Channel state information resource activation

Abstract

Example embodiments of the present disclosure are directed to channel state information resource activation. A method comprises receiving, from a second apparatus prior to a cell switch command reception, a mobility configuration including a configuration indicating Channel State Information, CSI, reference signal, RS, ports or CSI-RS resources for a CSI acquisition for a target cell for a cell switch; determining, after the cell switch command reception based on the configuration, one or more active CSI RS ports or CSI-RS resources in a target cell for the CSI acquisition for the target cell; and performing measurements for the CSI acquisition based on the determined one or more active CSI RS ports or CSI-RS resources

Description

CHANNEL STATE INFORMATION RESOURCE ACTIVATIONFIELD

[0001] Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, devices, apparatuses and computer readable storage medium for channel state information resource activation. BACKGROUND

[0002] With the continuous development of mobile networks, managing and optimizing user mobility between different network nodes has become crucial. Modern mobile communication systems require seamless connectivity between various network nodes to ensure efficient and reliable handovers. In order to ensure the communication continuousness in the wireless communication system, multiple technologies are proposed, such as cell switch. During the cell switch, the terminal device may switch among different cells. Further, technology of layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) may be used for enabling the cell switch. LTM is a procedure in which the next generation node B (gNB) receives LI and / or layer 3 (L3) measurement report(s) from a UE, and thus the gNB changes user equipment (UE) serving cell by a cell switch command signalled via a medium access control (MAC) control element (CE).SUMMARY

[0003] In a first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: receive, from a second apparatus prior to a cell switch command reception, a mobility configuration including a configuration including a configuration indicating Channel State Information, CSI, reference signal, RS, ports or CSI-RS resources for a CSI acquisition for a target cell for a cell switch; determine, after the cell switch command reception based on the configuration, one or more active CSI RS ports or CSI-RS resources in the target cell for the CSI acquisition for the target cell; and perform measurements for the CSI acquisition based on the determined one or more active CSI RS ports or CSI-RS resources.

[0004] In a second aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a second apparatus prior to a cell switch command reception, a mobility configuration including a configuration indicating Channel State Information, CSI, reference signal, RS, ports or CSI-RS resources for a CSI acquisition for a target cell for a cell switch; determining, after the cell switch command reception based on the configuration, one or more active CSI RS ports or CSI-RS resources in the target cell for the CSI acquisition for the target cell; and performing measurements for the CSI acquisition based on the determined one or more active CSI RS ports or CSI-RS resources.

[0005] In a third aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a second apparatus prior to a cell switch command reception, a mobility configuration including a configuration indicating Channel State Information, CSI, reference signal, RS, ports or CSI-RS resources for a CSI acquisition for a target cell for a cell switch; means for determining, after the cell switch command reception based on the configuration, one or more active CSI RS ports or CSI-RS resources in the target cell for the CSI acquisition for the target cell; and means for performing measurements for the CSI acquisition based on the determined one or more active CSI RS ports or CSI-RS resources.

[0006] In a fourth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the second aspect.

[0007] It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0009] FIG. 1 illustrates a signaling flow for an overall procedure for LTM;

[0010] FIG. 2A and FIG. 2B illustrate example communication environments in whichexample embodiments of the present disclosure can be implemented, respectively;

[0011] FIG. 3A and FIG. 3B illustrate procedures for CSI acquisition before / during LTM cell switch;

[0012] FIG. 4A and FIG. 4B illustrate example signaling flows for communication in accordance with some example embodiments of the present disclosure;

[0013] FIG. 5A to FIG. 5C illustrate example signaling flows for communication in accordance with some example embodiments of the present disclosure;

[0014] FIG. 6 illustrates an example of duration of active CSI-RS ports or CSI-RS resource in accordance with some example embodiments of the present disclosure;

[0015] FIG. 7 illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0016] FIG. 8 illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0017] FIG. 9 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0018] FIG. 10 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0019] Throughout the drawings, the same or similar reference numerals represent the same or similar element.DETAILED DESCRIPTION

[0020] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

[0021] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same mean as commonly understood by one ofordinary skills in the art to which this disclosure belongs.

[0022] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0023] It shall be understood that although the terms “first,” “second,”..., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0024] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0025] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

[0026] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements,components and / or combinations thereof.

[0027] As used in this application, the term “circuitry” may refer to one or more or all of the following:(a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and(b) combinations of hardware circuits and software, such as (as applicable):(i) a combination of analog and / or digital hardware circuit(s) with software / firmware and(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and(c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0028] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0029] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G),4.5G, the fifth generation (5G), 5.5G, the sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0030] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

[0031] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop -mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment(CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0032] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block (PRB)”, “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and / or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0033] As used herein, “inter-centralized unit (CU)” may refer to the interactions and handovers occurring between different centralized units within a mobile communication network. CUs are network nodes responsible for handling higher-layer functions such as radio resource control and mobility management. The term “inter-CU” specifically pertains to the processes, procedures, and mechanisms involved when a user equipment (UE) transitions from one CU to another, ensuring continuous and seamless connectivity during the handover.

[0034] As used herein, “intra-CU” may refer to the interactions and handovers occurring among different distributed units (DUs) or different gNBs of a same CU within a mobile communication network. The term “intra-CU” specifically pertains to the processes, procedures, and mechanisms involved when a UE transitions from one DU / gNB to another DU / gNB of a same CU, ensuring continuous and seamless connectivity during thehandover.

[0035] As mentioned above, technologies such as cell switch are proposed to ensure the communication continuousness in the wireless communication system. For example, LTM may be used for enabling the cell switch to reduce the mobility latency.

[0036] LTM is a cell switch procedure, where a serving cell of UE (primary cell, PCell or primary secondary cell, PSCell) is switched by the network by sending an LTM cell switch command. An LTM switch command is currently assumed delivered by MAC signaling using a MAC CE. Hence, not using radio resource control (RRC) signaling as a layer 3 (L3) based handover which is one of the current methods for changing between cells. LTM cell switch decision is based on measurements (for example layer 1, LI, measurements) that are performed and reported (for example LI measurement report) by the UE. Measurements and reporting are based on LTM candidate cell configuration provided by the network for one or more LTM candidate cells. An LTM candidate cell may be neighboring cells or a UE’s current serving cells (e.g. one of the current secondary cell).

[0037] In Release-18, LTM measurements on a neighboring candidate cell are performed using synchronization signal and physical broadcast channel (PBCH) blocks (SSBs) transmitted by the candidate cell for which the SSB configuration is provided to the UE.

[0038] Before the cell switch, the network may optionally activate one or more transmission configuration indicator (TCI) state(s) for one or more candidate cells for early downlink (DL) synchronization. Once a candidate cell TCI state is activated the UE may start tracking the downlink time / frequency synchronization using the reference signals associated with the activated TCI state(s). The UE may also perform early uplink (UL) synchronization before the cell switch if this is requested by the network.

[0039] Reference is now made to FIG. 1, which illustrates a signaling flow for an overall procedure for LTM. As illustrated in FIG. 1, at step 1, the UE sends a MeasurementReport message to the gNB. Based on the measurement report, and / or other conditions, the gNB decides to configure LTM and initiates LTM preparation. At step 2, the gNB transmits an RRCReconfiguration message to the UE, and the RRCRe configuration message includes the LTM candidate configurations. At step 3, the UE stores the LTM candidate configurations and transmits an RRCReconfigurationComplete message to the gNB.

[0040] At step 4a, the UE performs DL synchronization with the candidate cell(s) before receiving the cell switch command. At step 4b, when UE-based timing advance (TA) measurement is configured, UE acquires the TA value(s) of the candidate cell(s) by measurement. UE performs early TA acquisition with the candidate cell(s) as requested by the network before receiving the cell switch command. This is done via contention free random access (CFRA) triggered by a physical downlink control channel (PDCCH) order from the source cell, following which the UE sends preamble towards the indicated candidate cell. In order to minimize the data interruption of the source cell due to CFRA towards the candidate cell(s), the UE does not receive random access response from the network for the purpose of TA value acquisition and the TA value of the candidate cell is indicated in the cell switch command. The UE does not maintain the TA timer for the candidate cell and relies on network implementation to guarantee the TA validity.

[0041] At step 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 radio resource control (RRC) reconfiguration (step 2) is applicable.

[0042] At step 6, the gNB decides to execute cell switch to a target cell and transmits a medium access control (MAC) control element (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.

[0043] At step 7, the UE performs the random access procedure towards the target cell, if UE does not have valid TA of the target cell. At step 8, the UE completes the LTM cell switch procedure by sending RRCReconfigurationComplete message to target cell. If the UE has performed a random access (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 RA channel (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 uplink (UL) data. The steps 4-8 can be performed multiple times for subsequent LTM using the LTM candidate configuration(s) provided in step 2. The procedure over the air interface described above is applicable to both intra-gNB-DU LTM and inter-gNB-DU LTM.

[0044] One objective for LTM is CSI acquisition for candidate cells, i.e., enhancementsto LTM with CSI-RS measurements where enabling CSI acquisition (e.g., acquiring the channel information such as channel quality indicator (CQI), rank indicator (RI), precoding matric indicator (PMI) and so on) on candidate cell(s) based on CSI-RSs transmitted by the candidate cell(s). With this, the UE would be able to acquire and report the CSI parameters (CQI, PMI, RI, or / and LI) for a candidate cell, which then can be used for the transmission / reception in the target cell after the cell switch. This would reduce the need of additional measurements for CSI acquisition in the target cell for initial transmissions / receptions.

[0045] Measurements related enhancements include specifying necessary components to support event triggered LI measurement reporting, specifying support for CSI-RS measurements for LTM procedures and enable CSI-RS based beam management, and specifying CSI acquisition on candidate cell(s) based on CSI-RS before or during LTM cell switch. Further, Measurement related enhancements are applicable to Intra-CU master cell group (MCG) / secondary cell group (SCG) LTM and Inter-CU MCG / SCG LTM.

[0046] In the context of the present disclosure, term of CSI-related information acquisition may be replaced by CSI acquisition.

[0047] It should be noted that example embodiments discussed herein may be applicable to intra-CU cell switch, inter-CU cell switch, inter-gNB cell switch and so on. In summary, the present disclosure is not limited to the specific cell switch type.Example Environment

[0048] FIG. 2A shows an example communication environment 200A in which example embodiments of the present disclosure may be implemented. The network communication 200A includes a first apparatus 210, a second apparatus 220 and a third apparatus 230.

[0049] In some example embodiments, the first apparatus 210 may be comprised in a terminal device / apparatus and the second apparatus 220 / third apparatus 230 may be comprised in a network device / apparatus. Additionally, the second apparatuses 220 and the third apparatus 230 may provide one or more coverage areas, also called as cells. As illustrated in FIG. 2A, the communication environment 200A includes a cell 250 provided by the second apparatus 220 and a cell 260 provided by the third apparatus 230.

[0050] Further, in some example embodiments, the radio access network (RAN)architecture may include a centralized part, or central unit (CU), and a distributed part, or distributed unit (DU). The CU and the DU may be connected to one another by a so-called Fl interface. In the example of FIG. 2A, the second apparatus 220 may refer to a base station (such as, the next generation node B, gNB), a gNB-CU and / or a gNB-DU. Similarly, the third apparatus 230 also may refer to a base station (such as, a gNB), a gNB CU and / or a gNB DU.

[0051] In the example of FIG. 2A, the first apparatus 210 may move over time. As illustrated in FIG. 2 A, the first apparatus 210 locates at different positions at different time points (T1 and T2). As moving, the first apparatus 210 may switch among different cells, i.e., a cell switch procedure. In the example of FIG. 2 A, the first apparatus 210 may switch from cell 250 to cell 260. For a better discussion, the cell 250 may be called as the first cell 250, the source cell 250 or the serving cell 250, and the cell 260 may be called as the second cell 260, the candidate cell 260. Further, in a case that the cell 260 is selected as a target cell, the cell 260 also may be called as the target cell 260.

[0052] Reference is now made to FIG. 2B, which illustrates other example communication environments 200B in which example embodiments of the present disclosure may be implemented. In the example (A) of FIG. 2B, the second apparatus 220 and the third apparatus 230 are gNB DUs, and both the second apparatus 220 and the third apparatus 230 are connected to a same gNB-CU. In the example (B) of FIG. 2B, the second apparatus 220 and the third apparatus 230 are gNB DUs, while the second apparatus 220 the third apparatus 230 are connected to two different gNB-CUs.

[0053] It should be noted examples (A) and (B) of FIG. 2B are two example communication environments of the present discourse which are illustrated only for the purpose of illustration without suggesting any limitations. In fact, the cell switch discussed herein may include at least one of the following: an inter-gNB cell switch, an intra-CU cell switch, or an inter-CU cell switch.

[0054] It is to be understood that the number of devices and their connections shown in FIG. 2A and FIG. 2B are only for the purpose of illustration without suggesting any limitation. The communication environments 200A and 200B may include any suitable number of devices configured to implement example embodiments of the present disclosure. Although not shown, it would be appreciated that one or more additionaldevices may be located in the cell, and one or more additional cells may be deployed in the communication environments 200 A and 200B. It is noted that although illustrated as a network device, the second apparatus 220 / the third apparatus 230 may be another device than a network device. Although illustrated as a terminal device, the first apparatus 210 may be another device than a terminal apparatus.

[0055] Communications in the communication environments 200A and 200B may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (1G), the second generation (2G), the third generation (3G), the fourth generation (4G), the fifth generation (5G), 5.5G, the sixth generation (6G), and the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.Work Principle and Example Signalling for Communication

[0056] In some solutions, three alternatives may be considered for the CSI acquisition related measurements and reporting: Alt-1: CSI-RS measurement and CSI reporting operations are performed before reception of LTM cell switch command (CSC) MAC CE, where the report is sent to the serving cell and transferred to the candidate / target cell(s); Alt-2: CSI-RS measurement can start before reception of LTM CSC MAC CE and CSI reporting operation is performed after reception of LTM CSC MAC CE, where the report is sent directly to target cell, as illustrated in FIG. 3 A; Alt-3: CSI-RS measurement and CSI reporting operations are performed after reception of LTM CSC MAC CE, as illustrated in FIG. 3B.

[0057] Generally speaking, the UE is not expected to have more active CSI-RS ports or active CSI-RS resources in active bandwidth parts (BWPs) than reported as capability. Inthe following specification section, the details on current timeline for active number of CSI-RS port or RSs for CSI measurements and reporting performed in the UE’s serving cell where the measurements are done on a serving cell or / and reports are sent to a serving cell are provided.

[0058] In any slot, the UE is not expected to have more active CSI-RS ports or active CSI-RS resources in active BWPs than reported as capability. Non-zero power (NZP) CSI-RS resource is active in a duration of time defined as follows. For aperiodic CSI-RS, starting from the end of the PDCCH containing the request and ending at the end of the scheduled PUSCH containing the report associated with this aperiodic CSI-RS. When the PDCCH candidates are associated with a search space set configured with searchSpaceLinkingld, for the purpose of determining the NZP CSI-RS resource active duration, the PDCCH candidate that ends later in time among the two linked PDCCH candidates is used. For semi-persistent CSI-RS, starting from the end of when the activation command is applied, and ending at the end of when the deactivation command is applied. For periodic CSI-RS, starting when the periodic CSI-RS is configured by higher layer signalling, and ending when the periodic CSI-RS configuration is released

[0059] In some solutions, when the CSI request field on a DCI triggers a CSI report(s) on PUSCH, the UE shall provide a valid CSI report for the / / -th triggered report, if the first uplink symbol to carry the corresponding CSI report(s) including the effect of the timing advance, starts no earlier than at symbol Zre / , and if the first uplink symbol to carry the / / -th CSI report including the effect of the timing advance, starts no earlier than at symbol Z'rej(n), where Zref is defined as the next uplink symbol with its CP startingafter the end of the last symbol of the PDCCH triggering the CSI report(s), and where Z'rej(n), is defined as the next uplink symbol with its CP starting TmCS, = (Z')(2048+ 144)- K1URafter the end of the last symbol in time of the latest of aperiodic CSI-RS resource for channel measurements, aperiodic CSI-IM used for interference measurements, and aperiodic NZP CSI-RS for interference measurement for a CSI-ReportConfig, or for all triggered sub-configurations if CSI-ReportConfig contains multiple sub-configurations, when aperiodic CSI-RS is used for channel measurement for the / / -th triggered CSI report, and where TSWitch is pre-defined and is applied only if Z of below Table 1 is applied.

[0060] Z, Z' and « are defined as:Z = max (Z(m)) and Z' = max (Z'(m)), where M is the number of updated m=0,...,M-l m=0,...,M-lCSI report(s), (Z(m),Z'(m)) corresponds to the m-th updated CSI report and is defined as- (Z1(Z- ) of the Table 1 if max{ PPDCCH, PCSI-RS, PUL} < 3 and if the CSI is triggered without a PUSCH with either transport block or HARQ-ACK or both when L = 0 CPUs are occupied and the CSI to be transmitted is a single CSI and corresponds to wideband frequency-granularity where the CSI corresponds to at most 4 CSI-RS ports in a single resource without CRI report and where CodebookType is set to 'typel-SinglePanel1or where reportQuantity is set to 'cri-RI-CQP, or-(Z^.ZQ') of the Table 2 if the CSI to be transmitted corresponds to wideband frequency-granularity where the CSI corresponds to at most 4 CSI-RS ports in a single resource without CRI report and where CodebookType is set to 'typel- SinglePanel' or where reportQuantity is set to 'cri-RI-CQT, or-(Z^.ZQ') of the Table 2 if the CSI to be transmitted corresponds to wideband frequency-granularity where the reportQuantity is set to 'ssb-Index-SINR', 'cri-SINR', 'ssb-Index-SINR- Index or 'cri-SINR- Index or-p of Table 1 and Table 2 corresponds to the min QIPDCCH, PCSI-RS, PUL) where the PPDCCH corresponds to the subcarrier spacing of the PDCCH with which the DCI was transmitted and puL corresponds to the subcarrier spacing of the PUSCH with which the CSI report is to be transmitted and pcsi-RS corresponds to the minimum subcarrier spacing of the aperiodic CSI-RS triggered by the DCI.

[0061] The above discussed Table 1 and Table 2 are listed in the following.Table 1: CSI computation delay requirement 1Table 2: CSI computation delay requirement 2

[0062] One of the motivations of LTM is to maintain high data transmission efficiency (or spectral efficiency) in the process of fast cell switch. To achieve this, CSI acquisition based on CSI-RS(s) for the candidate cells using the CSI-RS(s) measurements on transmitted by the candidate cells has been agreed as one of the objectives for Rel-19 LTM to be specified. With this, the UE would be able to acquire and report the CSI parameters (channel quality indicator, CQI, precoding matrix indicator, PMI, rank indicator, RI, or / and Layer indicator, LI) for a candidate cell, which then can be used for the transmission / reception in the target cell after the cell switch. This would reduce the need of additional measurements for CSI acquisition in the target cell for initial transmissions / receptions.

[0063] In the context of the present disclosure, term of CSLrelated information acquisition, CSI acquisition, and similar terms are used interchangeably which refers to for the UE to measure, measure and store, or acquire CSI related information such as one or more of CQI, RI, PMI, RSRP, CRI.

[0064] In the context of the present disclosure, term RS and CSLRS may be used interchangeably, but the proposed solutions can be applied to any other similar RS, for example, which follows the same time domain behavior (periodic, semi-persistent, aperiodic) as CSLRS.

[0065] For Layer 1 measurements and reporting in the serving cell(s), the timeline for active CSLRS ports and CSLRS resources is defined for periodic (P), semi-persistent (SP), and aperiodic (AP) CSLRSs used for measurements on the serving cell, or when the reports are sent to the serving cell. Each UE has a limited capability for the number of active CSLRS ports or CSLRS resources it can support in any given slot, therefore, it is crucial to specify the timeline for the active duration of each configured RS to minimizeambiguity between the network and the UE regarding the measurements the NW can configure. This information enables the network to optimize the configuration of measurements and reporting to align with the UE's capabilities.

[0066] For CSI acquisition for a candidate cell during a cell switch procedure (such as LTM), when a report is sent directly to the target cell after the reception of the cell switch command, the timing of the uplink slot containing the report cannot be determined at the time of measurements. Also, based on the UE capability, some UEs may start performing the measurements before the cell switch and some UE may only start the measurements after the reception of the cell switch command.

[0067] It is therefore important to properly define the timeline for the active duration of each CSI-RS used for CSI acquisition measurements, considering the timing of measurements and the cell switch in both the serving cell and the target cell (before and after the cell switch). Otherwise, undefined, non-optimal, or relaxed activation assumptions for CSI acquisition measurements of candidate cells in the current serving cell could negatively impact the serving cell's measurements (e.g., a reduced number of active CSI-RS resources for serving cell measurements).

[0068] The present disclosure addresses the challenge of defining the timeline for the active number of CSI-RS ports or resources used for CSI acquisition in both the serving and the target cell. In some example embodiments of the present disclosure, methods or rules are proposed for counting active RS (such as, CSI-RS) ports or active RS (such as, CSI-RS) resources associated with CSI acquisition-related measurements for one or more candidate cells in the current serving cell (mobility source cell), which will be discussed with reference to FIG. 4A. Specifically when the UE supports, performs, or is configured to perform measurements prior to the reception of the cell switch command. Specifically, solutions are provided for all types (periodic, semi-persistent, aperiodic) CSI-RSs, based on the timeline of activation / deactivation command or configuration, CSI computation time, cell switch command and so on. It is further proposed to determine the number of active CSI-RS ports or RSs for CSI acquisition measurements for candidate cells based on the UE’s capability.

[0069] In some other example embodiments of the present disclosure, methods / rules are proposed for counting active RS (CSI-RS) ports or active RS (CSI-RS) resourcesassociated with CSI acquisition related measurements in the target cell, after the UE is commanded to switch to that cell, when the UE performs or is configured to perform measurements after the reception of the cell switch command, which will be discussed with reference to FIG. 4B. Specifically, solutions are provided for all types (periodic, semi-persistent, aperiodic) CSI-RSs, based on the timeline of activation / deactivation command or configuration, RS transmission, decoding and processing of the target cell configuration, CSI computation time, cell switch command and so on.

[0070] In the context of the present disclosure, the case of that the RS is used solely for early CSI acquisition measurements as part of the mobility procedure and the case of that the RS is utilized for both CSI acquisition for mobility and the serving cell procedure (e.g., for beam management or CSI measurements and reporting for mobility without any cell change) are considered. Further, for semi-persistent RS, both of the above cases are considered when the activation was done prior or after / via the cell switch command.

[0071] In the context of the present disclosure, for an active CSI-RS port or CSI-RS, a UE is expected to make any measurement (and send a measurement report), whereas for an inactive (or a deactivated) CSI-RS port or CSI-RS, the UE is not expected (or does not) to make any measurement (and send a measurement report).

[0072] It is noted the order acts shown in FIGS. FIGS. 4A and 4B are only an example not limitation. Acts may be performed in any suitable manner. Example embodiments described with reference to FIGS. 4A and 4B may be implemented separately or combined in any manner. For example, one or more example embodiments shown in a single drawing may be combined with one or more example embodiments shown in one or more other drawings.

[0073] In the following discussion, a cell switch may comprise at least one of the following: an inter-gNB cell switch, an intra-CU cell switch, or an inter-CU cell switch.

[0074] Further, in the following discussions, the first apparatus 110 may comprise a terminal apparatus, the second apparatus 120 may comprise one of the following: a next generation node B (gNB) serving the first apparatus 110 (also called as a source gNB), a distributed unit (DU) connecting with the first apparatus 110 (also called as a source DU), or a centralized unit (CU) connecting with the source DU (also called as a source CU), and the third apparatus 130 may comprises one of the following: a target gNB (also calledas a target gNB), a target DU, or a target CU.

[0075] Example embodiments where the CSI-related information acquisition are performed before the cell switch are discussed with reference to FIG. 4A, which illustrates an example signaling flow 400A for communication in accordance with some example embodiments of the present disclosure.

[0076] As illustrated in FIG. 4A, in operation, the second apparatus 220 (such as, a CU, source DU, source gNB) transmits (410-1) a mobility configuration to the first apparatus 210, and the first apparatus 210 receives (410-2) the mobility configuration accordingly.

[0077] In some example embodiments, the mobility configuration is a radio resource control signaling comprising LTM configuration or handover-related configuration, such as, an RRCReconfiguration message.

[0078] In some example embodiments, the mobility configuration indicates a configuration indicating CSI-RS ports or CSI-RS resources for acquisition of a CSI-related information, also referred as a CSI acquisition herein, for at least one candidate cell.

[0079] In the example of FIG. 4A, based on the configuration prior to a cell switch command reception, the first apparatus 210 determines (420) one or more active CSI-RS ports or CSI-RS resources in a serving cell of the first apparatus 210 for the CSI acquisition for the at least one candidate cell.

[0080] Based on the determined one or more active CSI RS ports or CSI-RS resources prior to the cell switch command reception, the first apparatus 210 performs (430) measurements for the CSI acquisition.

[0081] In the following, example embodiments for determining whether the CSI-RS ports or CSI-RS resources are considered as active or inactive are discussed.

[0082] In some example embodiments, a RS resource or a RS port associated with a periodic CSI-RS resource associated with a candidate cell may be considered as being active in the serving cell during a time duration. In some example embodiments, the time duration may start from the end of when the mobility configuration containing the configuration of a periodic CSI-RS or a control command is applied.

[0083] In some example embodiments, the control command may be a control command for activating measurements using the periodic CSI-RS or activating the periodic CSI-RS. Alternatively, in some example embodiments, the control command may be a control command for activating or triggering CSI measurements associated with the CSI acquisition for the candidate cell, the control command may be a PDCCH order triggering a RACH transmission associated with for the candidate cell or the periodic CSI-RS. In some example embodiments, a PDCCH order triggering a RACH transmission may be associated with a CSI-RS when the PDCCH order contains a synchronization signal block (SSB) which is quasi co-located (QCLed) with the CSI-RS. Alternatively, in some example embodiments, the control command may be a candidate TCI activation command for activating the TCI state associated with the candidate cell or the periodic CSI-RS.

[0084] Regarding the ending of the time duration, in some example embodiments, the time duration may end until when the cell switch command is received. Alternatively, in some example embodiments, the time duration may end until when an acknowledgement is sent for the cell switch command. Alternatively, in some example embodiments, the time duration may end until a certain number of symbols after the latest occurrence of a periodic candidate RS resource no later than the cell switch command. In some example embodiments, the certain number of symbols may be associated with at least one of a CSI computation delay or a UE capability or measurement quantity to be measured or reported using the measurement on the CSI-RS.

[0085] Alternatively, in some example embodiments, the time duration may end until when a transmission configuration indicator, TCI, deactivation command deactivating a TCI state associated with the candidate cell or a TCI state associated with the periodic CSI-RS is received. In some example embodiments, a TCI state may be associated with a CSI-RS when the TCI state contains a synchronization signal block (SSB) information which is quasi co-located (QCLed) with the CSI-RS.

[0086] In some example embodiments, a RS resource or a RS port associated with a SP CSI-RS resource associated with a candidate cell may be considered as being active in the serving cell during a time duration. In some example embodiments, the time duration may start from the end of when an activation command activating the SP CSI-RS or a measurement using the SP CSI-RS is applied.

[0087] Regarding the ending of the time duration, in some example embodiments, the time duration may end until when the cell switch command is received. Alternatively, in some example embodiments, the time duration may end until when an acknowledgement is sent for the cell switch command. Alternatively, in some example embodiments, the time duration may end until when a deactivation command is applied if the deactivation command is received before the cell switch command. Alternatively, in some example embodiments, the time duration may end until a certain number (as discussed above) of symbols after the latest occurrence of SP candidate RS resource no later than the cell switch command. In some example embodiments, the certain number of symbols may be associated with at least one of a CSI computation delay or a UE capability or measurement quantity to be measured or reported using the measurement on the CSI-RS. Alternatively, in some example embodiments, the time duration may end until when a TCI deactivation command deactivating a TCI state associated with the candidate cell or a TCI state associated with the SP CSI-RS is received.

[0088] In some example embodiments, a RS resource or a RS port associated with an aperiodic CSI-RS resource associated with a candidate cell may be considered as being active in the serving cell during a time duration. In some example embodiments, the time duration may start from a control command activating the aperiodic CSI-RS or a measurement using the aperiodic CSI-RS is applied or from the first symbol of the earliest occurrence of the aperiodic CSI-RS after the control command.

[0089] Regarding the ending of the time duration, in some example embodiments, the time duration may end at a time reference when the cell switch command is received. Alternatively, in some example embodiments, the time duration may end until when an acknowledgement is sent for the cell switch command. Alternatively, in some example embodiments, the time duration may end until a certain number of symbols after a reception of the aperiodic RS. In some example embodiments, the certain number of symbols may be associated with at least one of a CSI computation delay or a UE capability or measurement quantity to be measured or reported using the measurement on the CSI-RS.

[0090] According to some example embodiments of the present disclosure, the maximum number of active CSI-RS ports or active CSI-RS resources for the CSI acquisition may be reported / indicated to the second apparats 220 as discussed below.

[0091] In some example embodiments, the first apparatus 210 may indicate the maximum number of active CSI-RS ports or active CSI-RS resources for the CSI acquisition for the at least one candidate cell to the second apparatus 220.

[0092] In some example embodiments, the maximum number of active CSI-RS ports or active CSI-RS resources may be different from the maximum number of active CSI-RS ports or active CSI-RS resources, supported by the first apparatus 210, for CSI measurements reports sent to the serving cell. The CSI measurements reports sent to the serving cell may be associated with the measurements for beam management, or intra-cell / inter-cell mobility. Alternatively, in some example embodiments, the maximum number of active CSI-RS ports or active CSI-RS resources may the same with the maximum number of active CSI-RS ports or active CSI-RS resources, supported by the first apparatus 210, for CSI measurements reports sent to the serving cell.

[0093] In some example embodiments, the first apparatus 210 may transmit capability information to the second apparatus 220, where the capability information indicates the number of active CSI-RS ports or active CSI-RS resources, supported by the first apparatus 210, for CSI calculations for the at least one candidate cell.

[0094] In some cases, to trigger a cell switch to the target cell, the second apparatus 220 transmits (440-1) a cell switch command to the first apparatus 210, and the first apparatus 210 receives (440-2) the cell switch command accordingly. Then, the first apparatus 210 transmits a CSI report, generated based on the measurements for the CSI acquisition including information of acquired CSI related to one or more measurement quantities for the target cell, to the target cell. In some example embodiments, the measurement quantity comprises at least one of the following: a RI, a PMI, a CQI, CRI, a LI or a RSRP.

[0095] Example embodiments where the CSI-related information acquisition are performed after the cell switch are discussed with reference to FIG. 4B, which illustrates an example signaling flow 400B for communication in accordance with some example embodiments of the present disclosure.

[0096] As illustrated in FIG. 4B, in operation, the second apparatus 220 (such as, a CU, source DU, source gNB) transmits (450-1) a mobility configuration to the first apparatus 210, and the first apparatus 210 receives (450-2) the mobility configuration accordingly.

[0097] In some example embodiments, the mobility configuration is a radio resourcecontrol signaling comprising LTM configuration or handover-related configuration, such as, an RRCReconfiguration message.

[0098] In some cases, to trigger a cell switch to a target cell, the second apparatus 220 transmits (460-1) a cell switch command to the first apparatus 210, and the first apparatus 210 receives (460-2) the cell switch command accordingly.

[0099] In the example of FIG. 4B, after the cell switch command reception, the first apparatus 210 determines (470) one or more active CSI RS ports or CSI-RS resources for the CSI acquisition for the target cell based on the mobility configuration. Then, based on the determined one or more active CSI RS ports or CSI-RS resources prior to the cell switch command reception, the first apparatus 210 may perform (480) measurements for the CSI acquisition.

[0100] In the following, example embodiments for determining whether the CSI-RS ports or CSI-RS resources are considered as active or inactive are discussed.

[0101] In some example embodiments, a RS resource or a RS port associated with a periodic CSI-RS resource associated with the measurements for the target cell may be considered as being active in the target cell during a time duration. Regarding the starting of the time duration, in some example embodiments, the time duration may start from the last symbol of an uplink slot carrying an acknowledgment for the cell switch command indicating the target cell.

[0102] Alternatively, in some example embodiments, the time duration may start from the last symbol of the downlink slot carrying the cell switch command indicating the target cell. Alternatively, in some example embodiments, the time duration may start from the end of when the cell switch command indicating the target cell is applied. Alternatively, in some example embodiments, the time duration may start from the first symbol of the earliest occurrence of a periodic CSI-RS after the cell switch command. Alternatively, in some example embodiments, the time duration may start from the end of when the first apparatus 210 completes and processes a target cell configuration after receiving the cell switch command indicating the target cell.

[0103] Regarding the ending of the time duration, in some example embodiments, the time duration may end until the end of an uplink slot containing a CSI report associated with the periodic CSI-RS. In some examples, the CSI report may be sent in a specificuplink message to the target cell, e.g., in the message containing the RRC Reconfiguration Complete message, which may be a configured grant or a dynamic grant based first uplink message in a RACH-less cell switch or a message 3 sent during the RACH procedure in a RACH-based cell switch. In some examples, the UE may be provided a dynamic uplink grant to send the CSI report. Alternatively, in some example embodiments, the time duration may end until a certain number of symbols after the latest occurrence of a periodic CSI-RS resource after the cell switch command but before an uplink slot containing a CSI report associated with the periodic CSI-RS. Alternatively, in some example embodiments, the time duration may end until the periodic CSI-RS configuration is released in the target cell of the first apparatus 210. Alternatively, in some example embodiments, the time duration may end until a reconfiguration message associated with mobility configuration is received.

[0104] In some example embodiments, the ending of the duration or a configuration indicative of the ending time may be defined or configured in the mobility configuration. Alternatively, in some example embodiments, the time duration may end until the periodic CSI-RS configuration is released in the target cell of the first apparatus 210 if the periodic RS configured for the CSI acquisition in the mobility configuration is used for CSI measurement reporting for the serving cell procedure in the target cell.

[0105] In some example embodiments, in accordance with receiving an activation command for a semi-persistent CSI-RS resource associated with the measurements after or along with the cell switch command, the first apparatus 210 may determine a RS resource or a RS port associated with the semi-persistent CSI-RS as being active in the target cell during a time duration starting from the end of when the activation command for the semi-persistent CSI-RS is applied.

[0106] In some example embodiments, in accordance with receiving an activation command for a semi-persistent CSI-RS resource associated with the measurements before the cell switch command, the first apparatus 210 may determine a RS resource or a RS port associated with the semi-persistent CSI-RS resource as being active in the target cell during a time duration.

[0107] Regarding the starting of the time duration, in some example embodiments, the time duration may start from the last symbol of an uplink slot carrying theacknowledgment for the cell switch command indicating the target cell. Alternatively, in some example embodiments, the time duration may start from the last symbol of a downlink slot carrying the cell switch command indicating the target cell. Alternatively, in some example embodiments, the time duration may start from the end of when the cell switch command indicating the target cell is applied. Alternatively, in some example embodiments, the time duration may start from the first symbol of the earliest occurrence of a semi-persistent CSI-RS after the cell switch command. Alternatively, in some example embodiments, the time duration may start from the end of when the first apparatus 210 completes and processes a target cell configuration after receiving the cell switch command indicating the target cell.

[0108] Regarding the ending of the time duration, in some example embodiments, the time duration may end until at the end of an uplink slot containing a CSI report associated with the semi-persistent RS. Alternatively, in some example embodiments, the time duration may end until a certain number of symbols after the latest occurrence of semi-persistent CSI-RS resource after the cell switch command but before an uplink slot containing a CSI report associated with the semi-persistent CSI-RS. Alternatively, in some example embodiments, the time duration may end at the end when a deactivation command for the semi-persistent CSI-RS is applied.

[0109] In some example embodiments, the ending of the duration or a configuration indicative of the ending time may be defined or configured in the mobility configuration.

[0110] In some example embodiments, a RS resource or a RS port associated with an aperiodic CSI-RS resource associated with the measurements may be considered as being active in the cell during a time duration. In some example embodiments, the time duration may start from a control command received after or along with the cell switch command activating the aperiodic CSI-RS or a measurement using the aperiodic CSI-RS is applied or from the first symbol of the earliest occurrence of the aperiodic CSI-RS after the cell switch command. In some example embodiments, the time duration may end at the end of the uplink slot containing a CSI report associated with the aperiodic CSI-RS or a certain number of symbols after a reception of the aperiodic CSI-RS.[OHl] Similar with example embodiments discussed with reference to FIG. 4A, according to some example embodiments of the present disclosure, in the example of FIG.4B, the maximum number of active CSI-RS ports or active CSI-RS resources for the CSI acquisition may be reported / indicated to the second apparats 220 as discussed below.

[0112] In some example embodiments, the first apparatus 210 may indicate the maximum number of active CSI-RS ports or active CSI-RS resources for the CSI acquisition for the at least one candidate cell to the second apparatus 220 or maximum number of active CSI-RS ports or active CSI-RS resources for the CSI acquisition for the CSI acquisition upon a switching of the first apparatus to the target cell.

[0113] In some example embodiments, the maximum number of active CSI-RS ports or active CSI-RS resources may be different from the maximum number of active CSI-RS ports or active CSI-RS resources, supported by the first apparatus 210, for CSI for measurements and reporting configured in a serving cell configuration of the target cell. In some examples, measurements and reporting configured in a serving cell configuration of the target cell refers to the measurements and reporting to be supported in the target cell for serving cell procedures of the target cell . Alternatively, in some example embodiments, the maximum number of active CSI-RS ports or active CSI-RS resources may the same with the maximum number of active CSI-RS ports or active CSI-RS resources, supported by the first apparatus 210, for CSI for measurement and reporting configured in a serving cell configuration of the target cell..

[0114] To better understand the above procedure, more examples will be discussed with reference to FIG. 5 A to FIG. 5C. In the example of FIG. 5 A to FIG. 5C, UE is used as an example of the first apparatus 210, source DU / CDU is used as an example of the second apparatus 220, target DU is used as an example of the third apparatus 230, cell 1 is used as an example of the serving cell, cell 2 is used as an example of the target cell.

[0115] In the example of FIG. 5 A, at step 1, UE capability for CSI Acquisition for candidate cells may be provided to the source CU, such as, UE supporting of making measurements before the cell switch, the number of supported active number of CSI-RS resources or ports for CSI calculations for candidate cells or any other related capability information discussed above.

[0116] At step 2, UE may provide L3 / L1 measurement report to the source DU, and at step 3, source DU may provide the L3 / L1 measurement report to the source CU via UL RRC message transfer. Then, at step 4, LTM candidate preparation procedure may beperformed.

[0117] With steps 5-7, LTM Configuration (i.e., mobility configuration as discussed above) may be provided to the UE, where the LTM configuration may contain the configuration of CSI-RSs for CSI Acquisition from Cell 2. UE also may transmit an RRC Reconfiguration Complete, i.e., an acknowledgement of the mobility configuration.

[0118] Example embodiments where the UE is able to make CSI acquisition before the cell switch will be discussed with reference to FIG. 5B.

[0119] In operation, (similar with the example embodiments discussed with reference to FIG. 4A) at step 8, UE determines the active number of CSLRS resources or CSLRS ports in Cell 1 for the configured / activated report configs or measurements, and at step 9, UE determines report configs or measurements for which measurements can be performed can be performed based on the determined active number of CSLRS resources

[0120] At step 10, UE performs measurements and acquires CSI using the valid determined P CSI-RSs from cell 2 and prepares for the reporting of measurements. At step 11, the UE receives cell change (i.e., CSC) (with Target Cell ID = cell 2) and at step 12, the CSI Report containing the CSI measurements may be transmitted on the target cell.

[0121] More operations in the cell 1 (in the serving cell) are further discussed. In one example embodiment, for a CSI report for one or more candidate cells, or for CSI measurements associated with CSI acquisition for one or more candidate cells, the rules for counting active RS (CSLRS) ports or active RS (CSLRS) resources may be defined in the current serving cell (mobility source cell) when the UE supports, performs, or is configured to perform measurements prior to the reception of the cell switch command.

[0122] In some example embodiments, a periodic RS (e.g., CSLRS) resource associated with a candidate cell may be considered active in the current serving cell in a duration of time, starting from the end of when HO / LTM configuration containing the configuration of the RS or a control command (e.g., activating the measurements using the periodic RS) is applied, and ending when the cell switch command is received or an acknowledgement is sent for the cell switch command. Examples for control command may include “activating / triggering the CSI measurements associated with the CSI acquisition for the candidate cell”, “candidate TCI activation / deactivation command activating / deactivating a TCI state associated with the candidate cell”, or “a PDCCH order triggering an earlyPRACH transmission towards the candidate cell

[0123] In some example embodiments, the ending point may be the Z’ symbols (CSI computation delay based on UE capability, or this may be configured) after the latest occurrence of P candidate RS resource no later than the cell switch command. If this exceeds the cell switch command, the above option using the ending point based on the cell switch command may be used.

[0124] In some example embodiments, the ending point may be TCI deactivation command deactivating a TCI state associated with candidate cell or a TCI state associated with the periodic RS.

[0125] In some example embodiments, a semi-persistent RS (e.g., CSI-RS) resource associated with a candidate cell is considered active in the current serving cell in a duration of time, starting from the end of when the activation command activating the RS is applied, and ending when the cell switch command is received or an acknowledgement is sent for the cell switch command.

[0126] In some example embodiments, the ending point may be the end of when the deactivation command is applied if a deactivation command is received before the cell switch command.

[0127] In some example embodiments, the ending point may be the Z’ symbols (CSI computation delay based on UE capability, or this may be configured) after the latest occurrence of SP candidate RS resource no later than the cell switch command. If this exceeds the cell switch command, the above option using the ending point based on the cell switch command may be used.

[0128] In some example embodiments, the ending point may be TCI deactivation command deactivating a TCI state associated with candidate cell or a TCI state associated with the periodic RS.

[0129] In some example embodiments, an aperiodic RS (e.g., CSI-RS) resource associated with a candidate cell is considered active in the current serving cell in a duration of time, starting from the control command activating the RS is applied or from the first symbol of the earliest occurrence of the RS after the command, and ending when the cell switch command is received, or an acknowledgement is sent for the cell switchcommand.

[0130] In some example embodiments the ending point may be the Z’ symbols (CSI computation delay based on UE capability, or this may be configured) after the reception of the RS. If this exceeds the cell switch command, the above option using the ending point based on the cell switch command may be used.

[0131] In some example embodiments, the UE may indicate the maximum number of active CSI-RS ports or active CSI-RS resources for CSI acquisition measurements for mobility candidate cells (for which the reporting is sent to the candidate cell). In some example embodiments, this may be a separate UE capability (or limit) from the number of supported active CSI-RS ports or active CSI-RS resources for measurement reporting sent to the serving cell.

[0132] In some example embodiments, the number of supported active CSI-RS ports or active CSI-RS resources for measurement reporting sent to the serving cell may also apply to the number of active CSI-RS ports or active CSI-RS resources for CSI acquisition measurements for mobility candidate cells.

[0133] In some example embodiments, in any slot, the UE is not expected to have more active CSI-RS ports or active CSI-RS resources than reported as capability. In some example embodiments, the CSI report is configured to be sent to the target cell after receiving the cell switch command indicating the candidate cell for cell switch.

[0134] In some example embodiments, the CSI report may contain the information of acquired CSI for the candidate cell, in terms of at least one of the measurement quantities: CQI, RI, PMI, CRI, etc.

[0135] In some example embodiments, the configuration of the CSI report and associated measurement RSs (along with number of ports information) may be given in the Handover (HO) or LTM configuration.

[0136] Example embodiments where the UE is able to make CSI acquisition after or during the cell switch will be discussed with reference to FIG. 5C.

[0137] At step 13, the UE receives cell change (i.e., CSC) (with Target Cell ID = cell 2).

[0138] Similar with the example embodiments discussed with reference to FIG. 4B, atstep 14, UE determines active number of CSI-RS resources or CSI-RS ports in cell 2 for the configured / activated report configs or measurements, and at step 15, UE determines report configs or measurements for which measurements can be performed can be performed based on the determined active number of CSI-RS resources or CSI-RS ports.

[0139] At step 16, UE performs measurements and acquires CSI using the valid determined P CSI-RSs from cell 2 and prepare for the reporting of measurements, and at step 17, the CSI Report containing the CSI measurements may be transmitted on the target cell.

[0140] More operations in the cell 2 (in the target cell) are further discussed. In one example embodiment, for a cell, for CSI measurements performed before or during a cell switch procedure (or for CSI measurements associated with early CSI acquisition), the rules for counting active RS (CSI-RS) ports or active RS (CSI-RS) resources may be defined.

[0141] In one example embodiment, for a cell, for CSI measurements performed before or during a cell switch procedure (or for CSI measurements associated with early CSI acquisition), the rules for counting active RS (CSI-RS) ports or active RS (CSI-RS) resources may be defined only when the UE performs or is configured to perform measurements after the reception of the cell switch command.

[0142] In some example embodiments, a periodic RS (e.g., CSI-RS) resource associated with the CSI measurements performed is considered active in the cell during a time duration that starts from the last symbol of the uplink slot (PUCCH / PUSCH) carrying the acknowledgment for the cell switch command indicating the cell as the target cell, or from the last symbol of the downlink slot carrying the cell switch command indicating the cell as the target cell, or from the end of when the cell switch command is applied, or from the first symbol of the earliest occurrence of the RS after the cell switch command, or from the end of when the UE completes and processes the target cell configuration after receiving the cell switch command indicating the cell as the target cell.

[0143] In some example embodiments (referred to as Option A), the time duration ends at the end of the uplink slot (PUCCH / PUSCH) containing the report associated with this RS. This may be applicable when the CSI-RS is not required to be measured in the target cell after the report

[0144] In some example embodiments, the ending point may be the Z’ symbols (CSI computation delay based on UE capability, or this may be configured) after the latest occurrence of P candidate RS resource after the cell switch command but before the uplink slot (PUCCH / PUSCH) containing the report associated with this RS. If this exceeds the reporting slot, the above option using the ending point based on the reporting slot may be used.

[0145] In some example embodiments (referred to as Option A-l), the time duration ends until the periodic CSI-RS configuration is released in the cell. This may be applicable when the CSI-RS may be used for measurements for serving cell procedures in the target cell.

[0146] In some example embodiments (referred to as Option A-2), the time duration ends until the RRC reconfiguration (HO / LTM reconfiguration) is received. This may be applicable when the CSI-RS may be used for measurements for subsequent cell switches so the UE may assume such CSI-RS always active until a new configuration is received.

[0147] The specific option to be applied, such as Option A or Option A-l or Option A-2, may be defined or configured in the HO / LTM configuration. For example, Option A-l may be applicable when the RS configured for the mobility procedure (CSI acquisition) in the HO / LTM configuration is also used for the serving cell procedure (e.g., configured in the serving cell configuration).

[0148] In some example embodiments, when the activation command for a semi-persistent RS (e.g., CSI-RS) resource associated with the CSI measurements is received after or along with the cell switch command (indicating the cell as the target cell), the semi-persistent RS (e.g., CSI-RS) resource is considered active in the cell in a duration of time that starts from the end of when the activation command activating the RS is applied.

[0149] In some example embodiments, when the activation command for a semi-persistent RS (e.g., CSI-RS) resource associated with the CSI measurements is received before the cell switch command indicating the cell as the target cell, the semi-persistent RS (e.g., CSI-RS) resource is considered active in a duration of time that starts from the last symbol of the uplink slot (PUCCH / PUSCH) carrying the acknowledgment for the cell switch command indicating the cell as the target cell, or from the last symbol of the downlink slot carrying the cell switch command indicating the cell as the target cell, orfrom the end of when the cell switch command is applied, or from the first symbol of the earliest occurrence of the RS after the cell switch command, or from the end of when the UE completes and processes the target cell configuration after receiving the cell switch command indicating the cell as the target cell.

[0150] In some example embodiments (referred to as Option B), the time duration ends at the end of the uplink slot (PUCCH / PUSCH) containing the report associated with this RS (note: assuming that when the CSI-RS is not required to be measured in the target cell after the report).

[0151] In some example embodiments (referred to as Option B-l), the ending point may be the Z’ symbols (CSI computation delay based on UE capability, or this may be configured) after the latest occurrence of SP candidate RS resource after the cell switch command but before the uplink slot (PUCCH / PUSCH) containing the report associated with this RS. If this exceeds the reporting slot, the above option using the ending point based on the reporting slot may be used.

[0152] In some example embodiments (referred to as Option B-2), the ending point may be the end of when the deactivation command is applied.

[0153] In some example embodiments, the specific option to be applied, such as Option B or Option B-l or option B-2, may be defined or configured in the HO / LTM configuration.

[0154] In some example embodiments, an aperiodic RS (e.g., CSI-RS) resource associated with the CSI measurements considered active in the cell in a duration of time, starting from the control command received after or along with the cell switch command (indicating the cell as the target cell) activating the RS is applied or from the first symbol of the earliest occurrence of the RS after the command, and ending at the end of the uplink slot (PUCCH / PUSCH) containing the report associated with this RS.

[0155] In some example embodiments, the ending point may be the Z’ symbols (CSI computation delay) after the reception of the RS. If this exceeds the reporting slot, the above option using the ending point based on the reporting slot may be used

[0156] In some example embodiments, the UE may indicate the maximum number of active CSI-RS ports or active CSI-RS resources for early CSI acquisition measurementswhen the UE switches to the cell.

[0157] In some example embodiments, this may be a separate UE capability (or limit) from the number of supported active CSI-RS ports or active CSI-RS resources for measurements configured in the serving cell configuration (not in the HO / LTM configuration) of the target cell.

[0158] In some example embodiments, the number of supported active CSI-RS ports or active CSI-RS resources for measurements configured in the serving cell configuration may also apply to the number of active CSI-RS ports or active CSI-RS resources for early CSI acquisition measurements.

[0159] In some example embodiments, in any slot, the UE is not expected to have more active CSI-RS ports or active CSI-RS resources than reported as capability.

[0160] In some example embodiments, the CSI report is configured to be sent to the target cell after receiving the cell switch command indicating the candidate cell for cell switch. In some example embodiments, it is indicated in the cell switch command to perform measurements or / and send a CSI report to the target cell after receiving the cell switch command.

[0161] In some example embodiments, the CSI report may contain the information acquired CSI for the candidate cell, in terms of at least one of the measurement quantities: CQI, RI, PMI, CRI and so on.

[0162] In some example embodiments, the configuration of the CSI report and associated measurement RSs (along with number of ports information) may be given in the Handover (HO) or LTM configuration.

[0163] Reference is now made to FIG. 6. In the example of FIG. 6, for the serving cell, a periodic CSI-RS resource is considered active starting from the end of when a control command (e.g., activating the measurements using the periodic RS) is applied, and ending when the cell switch command is received. It is applied when the UE performs or configured to perform measurements for CSI acquisition before the reception of the cell switch command. And for the target cell, it is considered active starting from the end of when the cell switch command is applied until the end of the reporting slot. It is applied when the UE performs or configured to perform measurements for CSI acquisition afterthe reception of the cell switch command.

[0164] According to the above procedures, rules for active number of CSI-RS ports or CSI-RS resources timeline have been well defined for both serving and the target cell based on whether the UE makes measurement before the reception of the cell switch command. As a result, the network device may use this information to configure different measurements and reports appropriately.Example Methods

[0165] FIG. 7 shows a flowchart of an example method 700 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 700 will be described from the perspective of the first apparatus 210 in FIG. 2 A and FIG. 2B.

[0166] At block 710, the first apparatus receives, from a second apparatus, a mobility configuration including a configuration indicating Channel State Information, CSI, reference signal, RS, ports or CSI-RS resources for a CSI acquisition for at least one candidate cell.

[0167] At block 720, the first apparatus determines, based on the configuration prior to a cell switch command reception, one or more active CSI-RS ports or CSI-RS resources in a serving cell of the first apparatus for the CSI acquisition for the at least one candidate cell.

[0168] At block 730, the first apparatus performs measurements for the CSI acquisition based on the determined one or more active CSI RS ports or CSI-RS resources prior to the cell switch command reception.

[0169] In some example embodiments, a RS resource or a RS port associated with a periodic CSI-RS resource associated with a candidate cell is considered as being active in the serving cell during a time duration starting from the end of when the mobility configuration containing the configuration of a periodic CSI-RS or a control command is applied, and ending until at least one of the following: when the cell switch command is received, when an acknowledgement is sent for the cell switch command, a certain number of symbols after the latest occurrence of a periodic candidate RS resource no later than the cell switch command, or when a transmission configuration indicator, TCI,deactivation command deactivating a TCI state associated with the candidate cell or a TCI state associated with the periodic CSI-RS is received.

[0170] In some example embodiments, the control command comprises at least one of the following: a control command for activating measurements using the periodic CSI-RS or activating the periodic CSI-RS, a control command for activating or triggering CSI measurements associated with the CSI acquisition for the candidate cell, a physical downlink control channel, PDCCH, order triggering a random access channel, RACH, transmission associated with for the candidate cell or the periodic CSI-RS, or candidate TCI activation command for activating the TCI state associated with the candidate cell or the periodic CSI-RS.

[0171] In some example embodiments, a RS resource or a RS port associated with a semi-persistent, SP, CSI-RS resource associated with a candidate cell is considered as being active in the serving cell during a time duration starting from the end of when an activation command activating the SP CSI-RS or a measurement using the SP CSI-RS is applied, and ending until at least one of the following: when the cell switch command is received, when an acknowledgement is sent for the cell switch command, when a deactivation command is applied if the deactivation command is received before the cell switch command, a certain number of symbols after the latest occurrence of SP candidate RS resource no later than the cell switch command, or when a TCI deactivation command deactivating a TCI state associated with the candidate cell or a TCI state associated with the SP CSI-RS is received.

[0172] In some example embodiments, a RS resource or a RS port associated with an aperiodic CSI-RS resource associated with a candidate cell is considered as being active in the serving cell during a time duration starting from a control command activating the aperiodic CSI-RS or a measurement using the aperiodic CSI-RS is applied or from the first symbol of the earliest occurrence of the aperiodic CSI-RS after the control command, and ending until at least one of the following: when the cell switch command is received, when an acknowledgement is sent for the cell switch command, or a certain number of symbols after a reception of the aperiodic RS.

[0173] In some example embodiments, the certain number of symbols is associated with at least one of a CSI computation delay or a UE capability or measurement quantity to bemeasured or reported using the measurement on the CSI-RS.

[0174] In some example embodiments, the first apparatus may indicate, to the second apparatus, the maximum number of active CSI-RS ports or active CSI-RS resources for the CSI acquisition for the at least one candidate cell.

[0175] In some example embodiments, the maximum number of active CSI-RS ports or active CSI-RS resources is different from or the same with the maximum number of active CSI-RS ports or active CSI-RS resources, supported by the first apparatus, for CSI measurements reports sent to the serving cell.

[0176] In some example embodiments, the first apparatus may receive the cell switch command from the second apparatus indicating a candidate cell (or the at least one candidate cell) as a target cell; transmitting, to the target cell for a cell switch, CSI report generated based on the measurements for the CSI acquisition including information of acquired CSI related to one or more measurement quantities for the target cell.

[0177] In some example embodiments, the measurement quantity comprises at least one of the following: a rank indicator, RI, a precoding matrix indicator, PMI, a channel quality indicator, CQI, or channel state information, CSI-reference signal, RS, a resource indicator, CRI, a layer indicator, LI, or a reference signal receiving power, RSRP.

[0178] In some example embodiments, the first apparatus may transmit, to the second apparatus, capability information indicating the number of active CSI-RS ports or active CSI-RS resources, supported by the first apparatus, for CSI calculations for the at least one candidate cell.

[0179] In some example embodiments, the mobility configuration is a Layer 1 / Layer 2 triggered Mobility, LTM, configuration.

[0180] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

[0181] FIG. 8 shows a flowchart of an example method 800 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 800 will be described from the perspective of the first apparatus 210 in FIG. 2 A and FIG. 2B.

[0182] At block 810, the first apparatus receives, from a second apparatus prior to a cell switch command reception, a mobility configuration including a configuration indicating Channel State Information, CSI, reference signal, RS, ports or CSI-RS resources for a CSI acquisition for a target cell for a cell switch (or for a cell switch operation, switching from the source cell to the target cell indicated in the cell switch command).

[0183] At block 820, the first apparatus determines, after the cell switch command reception based on the configuration, one or more active CSI RS ports or CSI-RS resources in the target cell for the CSI acquisition for the target cell.

[0184] At block 830, the first apparatus performs measurements for the CSI acquisition based on the determined one or more active CSI RS ports or CSI-RS resources.

[0185] In some example embodiments, a RS resource or a RS port associated with a periodic CSI-RS resource associated with the measurements for the target cell is considered as being active in the target cell during a time duration.

[0186] In some example embodiments, the time duration starts from at least one of the following: the last symbol of an uplink slot carrying an acknowledgment for the cell switch command indicating the target cell, the last symbol of the downlink slot carrying the cell switch command indicating the target cell, the end of when the cell switch command indicating the target cell is applied, the first symbol of the earliest occurrence of a periodic CSI-RS after the cell switch command, or the end of when the first apparatus completes and processes a target cell configuration after receiving the cell switch command indicating the target cell.

[0187] In some example embodiments, the time duration ends until at least one of the following: at the end of an uplink slot containing a CSI report associated with the periodic CSI-RS, a certain number of symbols after the latest occurrence of a periodic CSI-RS resource after the cell switch command but before an uplink slot containing a CSI report associated with the periodic CSI-RS, the periodic CSI-RS configuration is released in the target cell of the first apparatus, or a reconfiguration message associated with mobility configuration, is received.

[0188] In some example embodiments, the ending of the duration is defined or configured in the mobility configuration.

[0189] In some example embodiments, the time duration ends until the periodic CSI-RS configuration is released in the target cell of the first apparatus if the periodic RS configured for the CSI acquisition in the mobility configuration is used for CSI measurement reporting for the serving cell procedure in the target cell.

[0190] In some example embodiments, in accordance with receiving an activation command for a semi-persistent CSI-RS resource associated with the measurements after or along with the cell switch command, the first apparatus may determine a RS resource or a RS port associated with the semi-persistent CSI-RS as being active in the target cell during a time duration starting from the end of when the activation command for the semi-persistent CSI-RS is applied.

[0191] In some example embodiments, in accordance with receiving an activation command for a semi-persistent CSI-RS resource associated with the measurements before the cell switch command, the first apparatus may determine a RS resource or a RS port associated with the semi-persistent CSI-RS resource as being active in the target cell during a time duration.

[0192] In some example embodiments, the time duration starts from at least one of the following: the last symbol of an uplink slot carrying the acknowledgment for the cell switch command indicating the target cell, or the last symbol of a downlink slot carrying the cell switch command indicating the target cell, or the end of when the cell switch command indicating the target cell is applied, or the first symbol of the earliest occurrence of a semi-persistent CSI-RS after the cell switch command, or the end of when the first apparatus completes and processes a target cell configuration after receiving the cell switch command indicating the target cell.

[0193] In some example embodiments, the time duration ends until at least one of the following: at the end of an uplink slot containing a CSI report associated with the semi-persistent RS, a certain number of symbols after the latest occurrence of semi-persistent CSI-RS resource after the cell switch command but before an uplink slot containing a CSI report associated with the semi-persistent CSI-RS, or the end when a deactivation command for the semi-persistent CSI-RS is applied.

[0194] In some example embodiments, the ending of the duration is defined or configured in the mobility configuration.

[0195] In some example embodiments, a RS resource or a RS port associated with an aperiodic CSI-RS resource associated with the measurements is considered as being active in the cell during a time duration starting from a control command received after or along with the cell switch command activating the aperiodic CSI-RS or a measurement using the aperiodic CSI-RS is applied or from the first symbol of the earliest occurrence of the aperiodic CSI-RS after the cell switch command, and ending at the end of the uplink slot containing a CSI report associated with the aperiodic CSI-RS or a certain number of symbols after a reception of the aperiodic CSI-RS.

[0196] In some example embodiments, the first apparatus may indicate, to the second apparatus, the maximum number of active CSI-RS ports or active CSI-RS resources for the CSI acquisition upon a switching of the first apparatus to the target cell.

[0197] In some example embodiments, the maximum number of active CSI-RS ports or active CSI-RS resources is different from or the same with the number of active CSI-RS ports or active CSI-RS resources that is supported by the first apparatus for measurement and reporting configured in a serving cell configuration of the target cell.

[0198] In some example embodiments, the first apparatus may transmit, to a target cell for a cell switch, CSI report generated based on the measurements for the CSI acquisition including information of acquired CSI related to one or more measurement quantities for the target cell.

[0199] In some example embodiments, the first apparatus may transmit, to the second apparatus, capability information indicating the number of active CSI-RS ports or active CSI-RS resources, supported by the first apparatus, for CSI calculations for the at least one candidate cell.

[0200] In some example embodiments, the mobility configuration is a Layer 1 / Layer 2 triggered Mobility, LTM, configuration.

[0201] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.Example Devices, apparatuses and CRMs

[0202] In some example embodiments, a first apparatus capable of performing any of the method 700 (for example, the first apparatus 210 in FIG. 2A and FIG. 2B) may comprisemeans for performing the respective operations of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 210 in FIG. 2 A and FIG. 2B.

[0203] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, a mobility configuration including a configuration indicating Channel State Information, CSI, reference signal, RS, ports or CSI-RS resources for a CSI acquisition for at least one candidate cell; means for determining, based on the configuration prior to a cell switch command reception, one or more active CSI-RS ports or CSI-RS resources in a serving cell of the first apparatus for the CSI acquisition for the at least one candidate cell; and means for performing measurements for the CSI acquisition based on the determined one or more active CSI RS ports or CSI-RS resources prior to the cell switch command reception.

[0204] In some example embodiments, a RS resource or a RS port associated with a periodic CSI-RS resource associated with a candidate cell is considered as being active in the serving cell during a time duration starting from the end of when the mobility configuration containing the configuration of a periodic CSI-RS or a control command is applied, and ending until at least one of the following: when the cell switch command is received, when an acknowledgement is sent for the cell switch command, a certain number of symbols after the latest occurrence of a periodic candidate RS resource no later than the cell switch command, or when a transmission configuration indicator, TCI, deactivation command deactivating a TCI state associated with the candidate cell or a TCI state associated with the periodic CSI-RS is received.

[0205] In some example embodiments, the control command comprises at least one of the following: a control command for activating measurements using the periodic CSI-RS or activating the periodic CSI-RS, a control command for activating or triggering CSI measurements associated with the CSI acquisition for the candidate cell, a physical downlink control channel, PDCCH, order triggering a random access channel, RACH, transmission associated with for the candidate cell or the periodic CSI-RS, or candidate TCI activation command for activating the TCI state associated with the candidate cell or the periodic CSI-RS.

[0206] In some example embodiments, a RS resource or a RS port associated with a semi-persistent, SP, CSI-RS resource associated with a candidate cell is considered as being active in the serving cell during a time duration starting from the end of when an activation command activating the SP CSI-RS or a measurement using the SP CSI-RS is applied, and ending until at least one of the following: when the cell switch command is received, when an acknowledgement is sent for the cell switch command, when a deactivation command is applied if the deactivation command is received before the cell switch command, a certain number of symbols after the latest occurrence of SP candidate RS resource no later than the cell switch command, or when a TCI deactivation command deactivating a TCI state associated with the candidate cell or a TCI state associated with the SP CSI-RS is received.

[0207] In some example embodiments, a RS resource or a RS port associated with an aperiodic CSI-RS resource associated with a candidate cell is considered as being active in the serving cell during a time duration starting from a control command activating the aperiodic CSI-RS or a measurement using the aperiodic CSI-RS is applied or from the first symbol of the earliest occurrence of the aperiodic CSI-RS after the control command, and ending until at least one of the following: when the cell switch command is received, when an acknowledgement is sent for the cell switch command, or a certain number of symbols after a reception of the aperiodic RS.

[0208] In some example embodiments, the certain number of symbols is associated with at least one of a CSI computation delay or a UE capability or measurement quantity to be measured or reported using the measurement on the CSI-RS.

[0209] In some example embodiments, the first apparatus further comprises: means for indicating, to the second apparatus, the maximum number of active CSI-RS ports or active CSI-RS resources for the CSI acquisition for the at least one candidate cell.

[0210] In some example embodiments, the maximum number of active CSI-RS ports or active CSI-RS resources is different from or the same with the maximum number of active CSI-RS ports or active CSI-RS resources, supported by the first apparatus, for CSI measurements reports sent to the serving cell.

[0211] In some example embodiments, the first apparatus further comprises: means for receiving the cell switch command from the second apparatus indicating a candidate cellas a target cell; means for transmitting, to the target cell for a cell switch, CSI report generated based on the measurements for the CSI acquisition including information of acquired CSI related to one or more measurement quantities for the target cell.

[0212] In some example embodiments, the measurement quantity comprises at least one of the following: a rank indicator, RI, a precoding matrix indicator, PMI, a channel quality indicator, CQI, or channel state information, CSI-reference signal, RS, a resource indicator, CRI, a layer indicator, LI, or a reference signal receiving power, RSRP.

[0213] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, capability information indicating the number of active CSLRS ports or active CSLRS resources, supported by the first apparatus, for CSI calculations for the at least one candidate cell.

[0214] In some example embodiments, the mobility configuration is a Layer 1 / Layer 2 triggered Mobility, LTM, configuration.

[0215] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

[0216] In some example embodiments, a first apparatus capable of performing any of the method 800 (for example, the first apparatus 210 in FIG. 2A and FIG. 2B) may comprise means for performing the respective operations of the method 800. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 210 in FIG. 2 A and FIG. 2B.

[0217] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus prior to a cell switch command reception, a mobility configuration including a configuration indicating Channel State Information, CSI, reference signal, RS, ports or CSLRS resources for a CSI acquisition for a target cell for a cell switch (or for a cell switch operation, switching from the source cell to the target cell indicated in the cell switch command); means for determining, after the cell switch command reception based on the configuration, one or more active CSI RS ports or CSL RS resources in the target cell for the CSI acquisition for the target cell; and means for performing measurements for the CSI acquisition based on the determined one or more active CSI RS ports or CSLRS resources.

[0218] In some example embodiments, a RS resource or a RS port associated with a periodic CSI-RS resource associated with the measurements for the target cell is considered as being active in the target cell during a time duration.

[0219] In some example embodiments, the time duration starts from at least one of the following: the last symbol of an uplink slot carrying an acknowledgment for the cell switch command indicating the target cell, the last symbol of the downlink slot carrying the cell switch command indicating the target cell, the end of when the cell switch command indicating the target cell is applied, the first symbol of the earliest occurrence of a periodic CSI-RS after the cell switch command, or the end of when the first apparatus completes and processes a target cell configuration after receiving the cell switch command indicating the target cell.

[0220] In some example embodiments, the time duration ends until at least one of the following: at the end of an uplink slot containing a CSI report associated with the periodic CSI-RS, a certain number of symbols after the latest occurrence of a periodic CSI-RS resource after the cell switch command but before an uplink slot containing a CSI report associated with the periodic CSI-RS, the periodic CSI-RS configuration is released in the target cell of the first apparatus, or a reconfiguration message associated with mobility configuration, is received.

[0221] In some example embodiments, the ending of the duration is defined or configured in the mobility configuration.

[0222] In some example embodiments, the time duration ends until the periodic CSI-RS configuration is released in the target cell of the first apparatus if the periodic RS configured for the CSI acquisition in the mobility configuration is used for CSI measurement reporting for the serving cell procedure in the target cell.

[0223] In some example embodiments, the first apparatus further comprises: means for in accordance with receiving an activation command for a semi-persistent CSI-RS resource associated with the measurements after or along with the cell switch command, determining a RS resource or a RS port associated with the semi-persistent CSI-RS as being active in the target cell during a time duration starting from the end of when the activation command for the semi-persistent CSI-RS is applied.

[0224] In some example embodiments, the first apparatus further comprises: means forin accordance with receiving an activation command for a semi-persistent CSI-RS resource associated with the measurements before the cell switch command, determining a RS resource or a RS port associated with the semi-persistent CSI-RS resource as being active in the target cell during a time duration.

[0225] In some example embodiments, the time duration starts from at least one of the following: the last symbol of an uplink slot carrying the acknowledgment for the cell switch command indicating the target cell, or the last symbol of a downlink slot carrying the cell switch command indicating the target cell, or the end of when the cell switch command indicating the target cell is applied, or the first symbol of the earliest occurrence of a semi-persistent CSI-RS after the cell switch command, or the end of when the first apparatus completes and processes a target cell configuration after receiving the cell switch command indicating the target cell.

[0226] In some example embodiments, the time duration ends until at least one of the following: at the end of an uplink slot containing a CSI report associated with the semi-persistent RS, a certain number of symbols after the latest occurrence of semi-persistent CSI-RS resource after the cell switch command but before an uplink slot containing a CSI report associated with the semi-persistent CSI-RS, or the end when a deactivation command for the semi-persistent CSI-RS is applied.

[0227] In some example embodiments, the ending of the duration is defined or configured in the mobility configuration.

[0228] In some example embodiments, a RS resource or a RS port associated with an aperiodic CSI-RS resource associated with the measurements is considered as being active in the cell during a time duration starting from a control command received after or along with the cell switch command activating the aperiodic CSI-RS or a measurement using the aperiodic CSI-RS is applied or from the first symbol of the earliest occurrence of the aperiodic CSI-RS after the cell switch command, and ending at the end of the uplink slot containing a CSI report associated with the aperiodic CSI-RS or a certain number of symbols after a reception of the aperiodic CSI-RS.

[0229] In some example embodiments, the first apparatus further comprises: means for indicating, to the second apparatus, the maximum number of active CSI-RS ports or active CSI-RS resources for the CSI acquisition upon a switching of the first apparatus to thetarget cell.

[0230] In some example embodiments, the maximum number of active CSI-RS ports or active CSI-RS resources is different from or the same with the number of active CSI-RS ports or active CSI-RS resources that is supported by the first apparatus for measurement and reporting configured in a serving cell configuration of the target cell.

[0231] In some example embodiments, the first apparatus further comprises: means for transmitting, to a target cell for a cell switch, CSI report generated based on the measurements for the CSI acquisition including information of acquired CSI related to one or more measurement quantities for the target cell.

[0232] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, capability information indicating the number of active CSI-RS ports or active CSI-RS resources, supported by the first apparatus, for CSI calculations for the at least one candidate cell.

[0233] In some example embodiments, the mobility configuration is a Layer 1 / Layer 2 triggered Mobility, LTM, configuration.

[0234] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

[0235] FIG. 9 is a simplified block diagram of a device 900 that is suitable for implementing example embodiments of the present disclosure. The device 900 may be provided to implement a communication device, for example, the first apparatus 210 and the second apparatus 220 in FIG. 2 A and FIG. 2B. As shown, the device 900 includes one or more processors 910, one or more memories 920 coupled to the processor 910, and one or more communication modules 940 coupled to the processor 910.

[0236] The communication module 940 is for bidirectional communications. The communication module 940 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 940 may include at least one antenna.

[0237] The processor 910 may be of any type suitable to the local technical network andmay include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 900 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0238] The memory 920 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 924, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), an optical disk, a laser disk, and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random-access memory (RAM) 922 and other volatile memories that will not last in the power-down duration.

[0239] A computer program 930 includes computer executable instructions that are executed by the associated processor 910. The instructions of the program 930 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 930 may be stored in the memory, e.g., the ROM 924. The processor 910 may perform any suitable actions and processing by loading the program 930 into the RAM 922.

[0240] The example embodiments of the present disclosure may be implemented by means of the program 930 so that the device 900 may perform any process of the disclosure as discussed with reference to FIG. 2A to FIG. 8. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0241] In some example embodiments, the program 930 may be tangibly contained in a computer readable medium which may be included in the device 900 (such as in the memory 920) or other storage devices that are accessible by the device 900. The device 900 may load the program 930 from the computer readable medium to the RAM 922 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storagepersistency (e.g., RAM vs. ROM).

[0242] FIG. 10 shows an example of the computer readable medium 1000 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 1000 has the program 930 stored thereon.

[0243] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0244] Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computerexecutable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0245] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general-purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions / operations specified inthe flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0246] In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0247] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random-access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0248] Further, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable sub-combination.

[0249] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the presentdisclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

I / We Claim:

1. A first apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to:receive, from a second apparatus prior to a cell switch command reception, a mobility configuration including a configuration indicating Channel State Information, CSI, reference signal, RS, ports or CSI-RS resources for a CSI acquisition for a target cell for a cell switch;determine, after the cell switch command reception based on the configuration, one or more active CSI RS ports or CSI-RS resources in the target cell for the CSI acquisition for the target cell; andperform measurements for the CSI acquisition based on the determined one or more active CSI RS ports or CSI-RS resources.

2. The first apparatus of claim 1, wherein a RS resource or a RS port associated with a periodic CSI-RS resource associated with the measurements for the target cell is considered as being active in the target cell during a time duration.

3. The first apparatus of claim 2, wherein the time duration starts from at least one of the following:the last symbol of an uplink slot carrying an acknowledgment for the cell switch command indicating the target cell,the last symbol of the downlink slot carrying the cell switch command indicating the target cell,the end of when the cell switch command indicating the target cell is applied, the first symbol of the earliest occurrence of a periodic CSI-RS after the cell switch command, orthe end of when the first apparatus completes and processes a target cell configuration after receiving the cell switch command indicating the target cell.

4. The first apparatus of claim 2 or 3, wherein the time duration ends until at least one of the following:at the end of an uplink slot containing a CSI report associated with the periodic CSI-RS,a certain number of symbols after the latest occurrence of a periodic CSI-RS resource after the cell switch command but before an uplink slot containing a CSI report associated with the periodic CSI-RS,the periodic CSI-RS configuration is released in the target cell of the first apparatus, ora reconfiguration message associated with mobility configuration, is received.

5. The first apparatus of claim 4, wherein the ending of the duration is defined or configured in the mobility configuration.

6. The first apparatus of claim 4, wherein the time duration ends until the periodic CSI-RS configuration is released in the target cell of the first apparatus if the periodic RS configured for the CSI acquisition in the mobility configuration is used for CSI measurement reporting for the serving cell procedure in the target cell.

7. The first apparatus of claim 1, wherein the first apparatus is caused to:in accordance with receiving an activation command for a semi-persistent CSI-RS resource associated with the measurements after or along with the cell switch command, determine a RS resource or a RS port associated with the semi-persistent CSI-RS as being active in the target cell during a time duration starting from the end of when the activation command for the semi-persistent CSI-RS is applied.

8. The first apparatus of claim 1, wherein the first apparatus is caused to:in accordance with receiving an activation command for a semi-persistent CSI-RS resource associated with the measurements before the cell switch command, determine a RS resource or a RS port associated with the semi-persistent CSI-RS resource as being active in the target cell during a time duration.

9. The first apparatus of claim 8, wherein the time duration starts from at least one of the following:the last symbol of an uplink slot carrying the acknowledgment for the cellswitch command indicating the target cell, orthe last symbol of a downlink slot carrying the cell switch command indicating the target cell, orthe end of when the cell switch command indicating the target cell is applied, orthe first symbol of the earliest occurrence of a semi-persistent CSI-RS after the cell switch command, orthe end of when the first apparatus completes and processes a target cell configuration after receiving the cell switch command indicating the target cell.

10. The first apparatus of any of claims 7-9, wherein the time duration ends until at least one of the following:at the end of an uplink slot containing a CSI report associated with the semi-persistent RS,a certain number of symbols after the latest occurrence of semi-persistent CSI-RS resource after the cell switch command but before an uplink slot containing a CSI report associated with the semi-persistent CSI-RS,the end when a deactivation command for the semi-persistent CSI-RS is applied.

11. The first apparatus of claim 10, wherein the ending of the duration is defined or configured in the mobility configuration.

12. The first apparatus of claim 1, wherein a RS resource or a RS port associated with an aperiodic CSI-RS resource associated with the measurements is considered as being active in the cell during a time duration starting from a control command received after or along with the cell switch command activating the aperiodic CSI-RS or a measurement using the aperiodic CSI-RS is applied or from the first symbol of the earliest occurrence of the aperiodic CSI-RS after the cell switch command, and ending at the end of the uplink slot containing a CSI report associated with the aperiodic CSI-RS or a certain number of symbols after a reception of the aperiodic CSI-RS.

13. The first apparatus of any of claims 1-12, wherein the first apparatus is caused to:indicate, to the second apparatus, the maximum number of active CSI-RS ports or active CSI-RS resources for the CSI acquisition upon a switching of the first apparatus to the target cell.

14. The first apparatus of claim 12, wherein the maximum number of active CSI-RS ports or active CSI-RS resources is different from or the same with the number of active CSI-RS ports or active CSI-RS resources that is supported by the first apparatus for measurement and reporting configured in a serving cell configuration of the target cell.

15. The first apparatus of any of claims 1-14, wherein the first apparatus is caused to:transmit, to a target cell for a cell switch, CSI report generated based on the measurements for the CSI acquisition including information of acquired CSI related to one or more measurement quantities for the target cell.

16. The first apparatus of any of claims 1-15, wherein the first apparatus is caused to:transmit, to the second apparatus, capability information indicating the number of active CSI-RS ports or active CSI-RS resources, supported by the first apparatus, for CSI calculations for the at least one candidate cell.

17. The first apparatus of any of claims 1-16, wherein the mobility configuration is a Layer 1 / Layer 2 triggered Mobility, LTM, configuration.

18. The first apparatus of any of claims 1-17, wherein the first apparatus comprises a terminal device and the second apparatus comprises a network device.

19. A method comprising:receiving, from a second apparatus prior to a cell switch command reception, a mobility configuration including a configuration indicating Channel State Information, CSI, reference signal, RS, ports or CSI-RS resources for a CSI acquisition for a target cell for a cell switch;determining, after the cell switch command reception based on the configuration, oneor more active CSI RS ports or CSI-RS resources in the target cell for the CSI acquisition for the target cell; andperforming measurements for the CSI acquisition based on the determined one or more active CSI RS ports or CSI-RS resources.

20. A first apparatus comprising:means for receiving, from a second apparatus prior to a cell switch command reception, a mobility configuration including a configuration indicating Channel State Information, CSI, reference signal, RS, ports or CSI-RS resources for a CSI acquisition for a target cell for a cell switch;means for determining, after the cell switch command reception based on the configuration, one or more active CSI RS ports or CSI-RS resources in the target cell for the CSI acquisition for the target cell; andmeans for performing measurements for the CSI acquisition based on the determined one or more active CSI RS ports or CSI-RS resources.

21. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 19.

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