Channel state information measurement for candidate cell during ltm

Abstract

Example embodiments of the present disclosure are directed to channel state information (CSI) measurement for candidate cell. A method comprises receiving, from a second apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; receiving, from the second apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration; and performing, based on the message, the at least one measurement based on the at least one reference signal without reporting the result of the measurement to the first cell.

Description

CHANNEL STATE INFORMATION MEASUREMENT FOR CANDIDATE CELLFIELD

[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 (CSI) measurement for candidate cell.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 layer 1 (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). The LTM procedure may be used to reduce the mobility latency.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 to: receive, from a second apparatus, a configuration regarding a channel state information (CSI) reporting, the configuration comprising at least one reference signal for at least one measurement for CSI of at least one candidate cell for a cell switch or mobility, wherein the configuration indicates the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration; and perform, based on the configuration, the at least one measurement based on the at least one reference signal without reporting the result of the atleast one measurement to the first cell.

[0004] In a second aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to: transmit, to a first apparatus, a configuration regarding a channel state information (CSI) reporting, the configuration comprising at least one reference signal for at least one measurement for CSI of at least one candidate cell for a cell switch or mobility, wherein the configuration indicates the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the configuration.

[0005] In a third 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 to: receive, from a second apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; receive, from the second apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration; and perform, based on the message, the at least one measurement based on the at least one reference signal without reporting the result of the measurement to the first cell.

[0006] In a fourth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to: transmit, to a first apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; and transmit, to the first apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration.

[0007] In a fifth 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 to: receive, from a second apparatus, a configuration of a set of reference signals for measurements of at least one candidate cell for a cell switch or mobility; receive, from the second apparatus, a message indicating at least one reference signal of the set of reference signals, the message further indicating to perform at least one measurement on the at least one reference signal for channel state information (CSI) of the at least one candidate cell without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the message; and perform, based on the message, the at least one measurement without transmitting the result to the first cell.

[0008] In a sixth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to: transmit, to a first apparatus, a configuration of a set of reference signals for measurements of at least one candidate cell for a cell switch or mobility; and transmit, to the first apparatus, a message indicating at least one reference signal of the set of reference signals, the message further indicating to perform at least one measurement on the at least one reference signal for channel state information (CSI) of the at least one candidate cell without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the message.

[0009] In a seventh aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a second apparatus, a configuration regarding a channel state information (CSI) reporting, the configuration comprising at least one reference signal for at least one measurement for CSI of at least one candidate cell for a cell switch or mobility, wherein the configuration indicates the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration; and performing, based on the configuration, the at least one measurement based on the at least one reference signal without reporting the result of the at least one measurement to the first cell.

[0010] In an eighth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a first apparatus, a configuration regarding a channel state information (CSI) reporting, the configuration comprising at least one reference signal for at least one measurement for CSI of at least one candidate cell for a cell switch or mobility,wherein the configuration indicates the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the configuration.

[0011] In a ninth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a second apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; receiving, from the second apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the configuration; and performing, based on the message, the at least one measurement based on the at least one reference signal without reporting the result of the measurement to the first cell.

[0012] In a tenth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a first apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; and transmitting, to the first apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration.

[0013] In an eleventh aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a second apparatus, a configuration of a set of reference signals for measurements of at least one candidate cell for a cell switch or mobility; receiving, from the second apparatus, a message indicating at least one reference signal of the set of reference signals, the message further indicating to perform at least one measurement on the at least one reference signal for channel state information (CSI) of the at least one candidate cell without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the message; and performing, based on the message, the at least one measurement without transmitting the result to the first cell.

[0014] In a twelfth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a first apparatus, a configuration of a set of reference signals for measurements of at least one candidate cell for a cell switch or mobility; and transmitting, tothe first apparatus, a message indicating at least one reference signal of the set of reference signals, the message further indicating to perform at least one measurement on the at least one reference signal for channel state information (CSI) of the at least one candidate cell without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the message.

[0015] In a thirteenth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a second apparatus, a configuration regarding a channel state information (CSI) reporting, the configuration comprising at least one reference signal for at least one measurement for CSI of at least one candidate cell for a cell switch or mobility, wherein the configuration indicates the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the configuration; and means for performing, based on the configuration, the at least one measurement based on the at least one reference signal without reporting the result of the at least one measurement to the first cell.

[0016] In a fourteenth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for transmitting, to a first apparatus, a configuration regarding a channel state information (CSI) reporting, the configuration comprising at least one reference signal for at least one measurement for CSI of at least one candidate cell for a cell switch or mobility, wherein the configuration indicates the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the configuration.

[0017] In a fifteenth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a second apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; means for receiving, from the second apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the configuration; and means for performing, based on the message, the at least one measurement based on the at least one reference signal without reporting the result of the measurement to the first cell.

[0018] In a sixteenth aspect of the present disclosure, there is provided a second apparatus.The second apparatus comprises means for transmitting, to a first apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; and means for transmitting, to the first apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration.

[0019] In a seventeenth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a second apparatus, a configuration of a set of reference signals for measurements of at least one candidate cell for a cell switch or mobility; means for receiving, from the second apparatus, a message indicating at least one reference signal of the set of reference signals, the message further indicating to perform at least one measurement on the at least one reference signal for channel state information (CSI) of the at least one candidate cell without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the message; and means for performing, based on the message, the at least one measurement without transmitting the result to the first cell.

[0020] In an eighteenth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for transmitting, to a first apparatus, a configuration of a set of reference signals for measurements of at least one candidate cell for a cell switch or mobility; and means for transmitting, to the first apparatus, a message indicating at least one reference signal of the set of reference signals, the message further indicating to perform at least one measurement on the at least one reference signal for channel state information (CSI) of the at least one candidate cell without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the message.

[0021] In a nineteenth 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 seventh aspect.

[0022] In a twentieth 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 eighth aspect.

[0023] In a twenty -first 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 ninth aspect.

[0024] In a twenty-second 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 tenth aspect.

[0025] In a twenty -third 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 eleventh aspect.

[0026] In a twenty-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 twelfth aspect.

[0027] 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

[0028] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0029] FIG. 1A and FIG. IB illustrate example communication environments in which example embodiments of the present disclosure can be implemented, respectively;

[0030] FIG. 2 illustrates an example signaling flow for layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) procedure;

[0031] FIG. 3 illustrates an example signaling flow for channel state information measurement for candidate cell in accordance with some example embodiments of the present disclosure;

[0032] FIG. 4 illustrates a schematic diagram of an example of LTM CSI reporting configuration in accordance with some example embodiments of the present disclosure;

[0033] FIG. 5 illustrates a schematic diagram of an example of LTM configuration inaccordance with some example embodiments of the present disclosure;

[0034] FIG. 6 illustrates an example signaling flow for channel state information measurement for candidate cell in accordance with some example embodiments of the present disclosure;

[0035] FIG. 7 illustrates another signaling flow for channel state information measurement for candidate cell in accordance with some example embodiments of the present disclosure;

[0036] FIG. 8 illustrates another example signaling flow for channel state information measurement for candidate cell in accordance with some example embodiments of the present disclosure;

[0037] FIG. 9 illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0038] FIG. 10 illustrates a flowchart of a method implemented at a second apparatus in accordance with some example embodiments of the present disclosure;

[0039] FIG. 11 illustrates another flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0040] FIG. 12 illustrates another flowchart of a method implemented at a second apparatus in accordance with some example embodiments of the present disclosure;

[0041] FIG. 13 illustrates another flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0042] FIG. 14 illustrates another flowchart of a method implemented at a second apparatus in accordance with some example embodiments of the present disclosure; and

[0043] FIG. 15 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0044] FIG. 16 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0045] Throughout the drawings, the same or similar reference numerals represent the same or similar element.DETAILED DESCRIPTION

[0046] 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.

[0047] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0048] 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.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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 nonterrestrial 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.

[0057] 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 npersonal 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.

[0058] 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.

[0059] 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.

[0060] 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 the handover.

[0061] FIG. 1A shows an example communication environment 100 A in which example embodiments of the present disclosure may be implemented. The network communication 100 A includes a first apparatus 110, a second apparatus 120 and a third apparatuses 130.

[0062] In some example embodiments, the first apparatus 110 may be comprised in a terminal device / apparatus and the second apparatus 120 / third apparatus 130 may be comprised in a network device / apparatus. Additionally, the second apparatuses 120 and the third apparatus 130 may provide one or more coverage areas, also called as cells. As illustrated in FIG. 1A, the communication environment 100A includes a cell 150 provided by the second apparatus 120 and a cell 160 provided by the second apparatus 120 provided by the third apparatus 130.

[0063] 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. 1A, the second apparatus 120 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 130 also may refer to a base station (such as, a gNB), a gNB CU and / or a gNB DU.

[0064] In the example of FIG. 1 A, the first apparatus 110 may move over time. As illustrated in FIG. 1 A, the first apparatus 110 locates at different positions at different time points (T1 and T2). As moving, the first apparatus 110 may switch among different cells, i.e., a cell switch procedure. In the example of FIG. 1 A, the first apparatus 110 may switch from cell 150 to cell 160. For a better discussion, the cell 150 may be called as the source cell 150 or the serving cell 150, and the cell 160 may be called as the candidate cell 160. Further, in a case that the cell 160 is selected as a target candidate cell, the cell 160 also may be called as the target candidate cell 160.

[0065] Reference is now made to FIG. IB, which illustrates other example communication environments 100B in which example embodiments of the present disclosure may be implemented. In the example (A) of FIG. IB, the second apparatus 120 and the third apparatus 130 are gNB DUs, and both the second apparatus 120 and the third apparatus 130 are connected to a same gNB-CU. In the example (B) of FIG. IB, the second apparatus 120 and the third apparatus 130 are gNB DUs, while the second apparatus 120 the third apparatus 130 areconnected to two different gNB-CUs.

[0066] Moreover, the first apparatus 110 in FIGS. 1 A and IB may support mobility, such as LTM or L3 based handover where the mobility execution is performed by the L3. In some mechanisms, the LTM procedure is proposed as FIG. 2.

[0067] It should be noted examples (A) and (B) of FIG. IB 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 intra-gNB cell switch, an inter-gNB cell switch, an intra-CU cell switch, or an inter-CU cell switch.

[0068] It is to be understood that the number of devices and their connections shown in FIG. 1A and FIG. IB are only for the purpose of illustration without suggesting any limitation. The communication environments 100 A and 100B may include any suitable number of devices configured to implementing example embodiments of the present disclosure. Although not shown, it would be appreciated that one or more additional devices may be located in the cell, and one or more additional cells may be deployed in the communication environments 100A and 100B. It is noted that although illustrated as a network device, the second apparatus 120 / the third apparatus 130 may be another device than a network device. Although illustrated as a terminal device, the first apparatus 110 may be another device than a terminal apparatus.

[0069] Communications in the communication environments 100 A and 100B 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.

[0070] As mentioned above, technologies such as cell switch are proposed to ensure the communication continuousness in the wireless communication system. For example, UE’s serving cell (e.g., a primary cell (PCell) or a primary synchronization cell (PSCell)) may be switched by the network by sending a LTM cell switch command. An LTM switch command may be currently assumed delivered by MAC (medium access control) signaling using a MAC CE (control element). Hence, radio resource control (RRC) signaling may be not used as a L3 based handover which is one of the current approaches for changing between cells. LTM cell switch decision may be based on LI measurements that are performed and reported using LI measurement reports by the UE. Measurements and reporting may be based on LTM candidate cell configuration provided by the network for one or more LTM candidate cells. An LTM candidate cell may be neighboring non-serving cells or a UE’s current serving cells (e.g. a secondary cell (SCell)).

[0071] In Release-18, LTM measurements on a neighboring candidate cell may be performed using synchronization signal blocks (SSB) transmitted by the candidate cell for which the SSB configuration is provided to the UE.

[0072] Before the cell switch, the network may optionally activate one or more transmission configuration indicator (TCI) state(s) for one or more candidate cells. Once a candidate cell TCI state is activated, the UE may start tracking the 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.

[0073] FIG. 2 illustrates an example signaling flow 200 for LTM procedure. The signaling flow 200 involves a UE 210 and a gNB 220. The UE 210 may be considered as an implementation of the first apparatus 110 in FIGS. 1 A and IB. The gNB 220 may be considered as an implementation of the second apparatus 120 in FIGS. 1A and IB.

[0074] As illustrated, at 2010, the UE 210 may be in RRC_CONNECTED state. At 2020, the UE 210 may transmit a measurement report to the gNB 220. With the measurement report, the gNB 220 may perform LTM candidate preparation at 2030. Then, at 2040, the gNB 220 may transmit a RRC reconfiguration to the UE 210. The RRC reconfiguration may include LTM candidate configuration. At 2050, the UE 210 may transmit a RRC reconfiguration complete message to the gNB 220. The procedures of 2010 to 2050 may be considered as LTM preparation.

[0075] Furthermore, at 2060, the UE 210 and the gNB 220 may perform the downlink (DL) synchronization with candidate cells. At 2070, the UE 210 and the gNB 220 may perform the UL synchronization with candidate cells. The procedures of 2060 and 2070 may be considered as early synchronization (referred to as “early sync”).

[0076] Subsequently, at 2080, the UE 210 may transmit LI measurement report to the gNB 220. At 2090, the gNB 220 may determine the LTM decision based on the LI measurement report from the UE 210. At 2100, the gNB 220 may transmit a cell switch command to the UE 210. The cell switch command may be transmitted via MAC CE. At 2110, the UE 210 may detach from source and apply target configurations. Additionally, at 2120, the UE 210 and the gNB 220 may perform a random access channel (RACH) procedure. The procedures of 2080 to 2120 may be considered as LTM execution.

[0077] At 2130, the UE 210 and the gNB 220 may perform an LTM completion procedure.

[0078] LTM was introduced in Rel-18 and may offer improvements in handover latency and interruption time compared to L3 based mobility. However, LTM as introduced in Rel-18 also has a number of limitations compared to L3 mobility. This Rel-19 work item aims to remove a number of these limitations with the following objectives. One of the objectives is to enable CSLreference signal (RS) measurements for LTM procedures.

[0079] It has been specified to support inter-CU L2 mobility (LTM). When CU is acting as the master node (MN) and dual connectivity (DC) is not configured, the case may be prioritized. As secondary priority, the case may be supported when NR-DC is configured and the CU is acting as a secondary node (SN) and the master cell group (MCG) is unchanged. As secondary priority, the case may be supported when NR-DC is configured, CU is acting as the MN and the secondary cell group (SCG) is unchanged or the SCG is released. Moreover, the case that LTM is configured in both MCG and SCG may be excluded. It is specified to support subsequent LTM mobility procedures aiming to avoid RRC configuration between cell switches as per Rel-18 LTM. For example, coordination with SA3 may be needed with respect to security key handling. Furthermore, intra-CU LTM procedure in Rel- 18 may be considered as baseline for adding inter-CU support.

[0080] Additionally, measurements related enhancements for purpose of supporting LTM are proposed. Specifically, measurement related enhancements may be applicable to intra-CU MCG / SCG LTM and inter-CU MCG / SCG LTM. Moreover, necessary components tosupport event triggered LI measurement reporting may be specified. CSLRS measurements for LTM procedures may be supported. CSLRS based beam management may be enabled. In addition, CSI acquisition on candidate cell(s) based on CSLRS before or during LTM cell switch may be specified. Furthermore, it is to be decided whether to support CSI report before or during the LTM cell switch, as part of the CSI acquisition procedure.

[0081] Furthermore, support of conditional intra-CU LTM may be specified. For instance, UE evaluated conditions for triggering LTM may be specified. Moreover, conditional LTM including subsequent LTM may be supported. The conditional LTM to the scenario where the UE is in non-DC may be specified with limitations. In addition, it may be checked whether the intra-CU conditional LTM is able to be specified to DC scenarios.

[0082] In addition, radio resource management (RRM) requirements related to the above objectives may be specified.

[0083] CSI acquisition (i.e. acquiring the channel parameters) such as channel quality indicator (CQI), precoding matrix indicator (PMI), layer indicator (LI), and rank indicator (RI), may be used to set the appropriate modulation, coding rate, and appropriate multiple-input multiple-output (MIMO) configuration (e.g., the number of layers, the precoding matrix) of the channel.

[0084] In Rel-19, agreements have been made related to CSLRS based LL reference signal receiving power (RSRP) measurements for candidate cells. Specifically, it has been agreed to support Ll-RSRP measurement based on CSLRS. Moreover, Ll-signal interference noise ratio (SINR) measurement based on CSLRS is to be supported.

[0085] Moreover, explicit configuration of CSLRS resource(s) for candidate cell(s) for LL measurement may be supported. CSLRS based Ll-RSRP report may be supported both for gNB scheduled and event triggered LI measurement reporting. Rel-18 LTM CSI reporting framework used for SSB based LI measurements may be the baseline for CSLRS based LL measurement report by gNB scheduled measurement reporting.

[0086] For gNB scheduled reporting and event triggered reporting, at least periodic CSLRS may be supported for Ll-RSRP measurement for candidate cell. Moreover, aperiodic and semi- persistent CSLRS may be supported. Additionally, at least CSLRS for beam management may be supported for Ll-RSRP measurement for candidate cell. CSLRS for mobility is to be supported.

[0087] Furthermore, UCI format may be used by replacing SS / PBCH Block resource indicator (SSBRI) with channel state information reference signal (CSI-RS) resource indicator (CRI). Whether the Ll-RSRP(s) of serving cell is always included may be configurable (in line with Rel-18). The quantization method and bit width defined in standards may be used. LI specified filtering for time and spatial domain may not be introduced. Enhancement on how to report L cells x M beams may be not included. Periodic reporting on physical uplink control channel (PUCCH) may be supported. Moreover, semi-persistent reporting on PUCCH / physical uplink shared channel (PUSCH), and aperiodic reporting on PUSCH are to be supported.

[0088] For CSI-RS based LI -measurement report by gNB scheduled measurement reporting, semi-persistent reporting on PUCCH / PUSCH and aperiodic reporting on PUSCH may be supported.

[0089] In addition, the procedures and mechanisms for CSI-RS based CSI acquisition for candidate cells need to be specified. Specifically, the CSI-RS measurement and the CSI reporting operations may be performed before reception of LTM cell switch command (CSC) MAC CE. The report may be sent to the serving cell and transferred to the candidate / target candidate cell(s).

[0090] Alternatively, the CSI-RS measurement may start before reception of the LTM CSC MAC CE and the CSI reporting operation may be performed after reception of the LTM CSC MAC CE. The report may be sent directly to the target candidate cell.

[0091] In some implementations, the CSI-RS measurement and the CSI reporting operations may be performed after reception of LTM CSC MAC CE. The report may be sent directly to the target candidate cell.

[0092] Moreover, it may be requested to provide the details of exact report timing and triggering mechanism.

[0093] Link adaptation may be important to have good spectral efficiency. Based on the link quality (channel parameters like CRI, CQI, PMI, RI, etc., also referred as CSI acquisition herein), appropriate modulation and coding rate for data channels, and aggregation level for control channel (e.g., physical downlink control channel (PDCCH)) may be determined.

[0094] 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 onCSI-RS for the candidate cells has been agreed as one of the objectives for Rel-19 LTM to be specified. In these cases, the UE may be able to acquire and report the CSI parameters (CQI, PMI, RI, or / and LI) for a candidate cell, which then may be used for the transmission / reception in the target candidate cell after the cell switch. The need of additional measurements for CSI acquisition in the target candidate cell for initial transmissions / receptions may be reduced.

[0095] It is to be studied for measurement and reporting timeline. For example, CSI-RS measurement and CSI reporting operations may be performed before reception of LTM cell switch command (CSC) MAC CE. The report may be sent to the serving cell and transferred to the candidate / target candidate cell(s).

[0096] Alternatively, CSI-RS measurement may start before reception of LTM CSC MAC CE and CSI reporting operation may be performed after reception of LTM CSC MAC CE. The report may be sent directly to target candidate cell.

[0097] In some mechanisms, CSI-RS measurement and CSI reporting operations may be performed after reception of LTM CSC MAC CE. The report may be sent directly to target candidate cell.

[0098] Typically, in a cell, LI measurements may be triggered by activating a report configuration that includes the measurement reference signal (RS) information (e.g., RS identifiers) to be used for measurements and reporting. This may require the UE to report the measurements to the cell where the reporting configuration is provided. For reporting, uplink (UL) resources may be allocated to the UE. Specifically, for periodic and semi-persistent (SP) reporting on PUCCH, resources may be provided along with the reporting configuration in the RRC configuration. For SP and aperiodic (AP) reporting on PUSCH, UL resources may be assigned through the downlink control information (DCI) that triggers SP and AP reporting.

[0099] In scenarios where the CSI measurements are triggered before the cell switch but CSI report is sent to a different cell (i.e., a mobility target candidate cell) from the cell where the report configuration is provided (i.e., within the serving cell config, e.g., ServingCellConfig, of the current serving cell, for example in the CSLMeasConfig information element) , the legacy mechanisms for triggering measurements by activating reporting along with UL resources may not apply. This is because the UL resources for reporting to the target candidate cell may not be known to the serving cell.

[0100] In order to solve at least part of the above problems or other potential problems, severalsolutions on CSI measurement for candidate cell such as CSI measurements for candidate cell in LTM are proposed. In a solution, a channel state information (CSI) reporting is configured as a part of the current serving configuration (e.g., within the serving cell config, e.g., ServingCellConfig, of the current serving cell, for example in the CSI-MeasConfig information element). The UE starts, based on the configuration, at least one measurement (e.g., a CSI measurement) based on at least one reference signal without reporting the result of the at least one measurement to a first cell including a serving cell of the UE or a cell providing the configuration. In this way, CSI measurements for candidate cells may be supported. Thus, the efficiency and effectiveness of the cell switch may be improved.

[0101] In another solution, a CSI reporting is configured. For example, the CSI report may be a part of the current serving configuration (e.g., within the serving cell config, e.g., ServingCellConfig, of the current serving cell, for example in the CSI-MeasConfig information element). The UE is triggered by a message from the gNB to start at least one measurement without reporting a result of the at least one measurement to a first cell including a serving cell of the UE or a cell providing the configuration. Such message-triggered CSI measurements for candidate cells may ensure that the flexibility and effectiveness of the cell switch are improved.

[0102] In a further solution, a set of reference signals for a CSI reporting is configured. For example, the CSI report may be a part of the current serving configuration (e.g., within the serving cell config, e.g., ServingCellConfig, of the current serving cell, for example in the CSI- MeasConfig information element). The UE is triggered by a message indicating at least one reference signal of the set of reference signals to start at least one measurement on the at least one reference signal for CSI of the candidate cells without reporting a result of the at least one measurement to a first cell. The first cell includes a serving cell of the UE or a cell providing the message. In this manner, CSI measurements related to reference signals for candidate cells may be supported. Thus, the effectiveness and accuracy of cell switch may be improved.

[0103] Several solutions of the present disclosure have been briefly described. Principle and implementations of the present disclosure will be described in detail below.

[0104] Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. It is noted the order acts shown in FIG. 3-8 are only an example not limitation. Acts may be performed in any suitable manner. Example embodiments described with reference to FIG. 3 to FIG. 8 may be implemented separately or combined in any manner. For example, one or more example embodiments shown in a singledrawing may be combined with one or more example embodiments shown in one or more other drawings.

[0105] In the following discussion, the cell switch may comprise at least one of the following: an intra-gNB cell switch, an inter-gNB cell switch, an intra-CU cell switch, or an inter-CU cell switch.

[0106] 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, a distributed unit (DU) connecting with the first apparatus 110, or a centralized unit (CU) connecting with the DU, and the third apparatus 130 may comprises one of the following: a target next generation node B (gNB), or a target distributed unit (DU).

[0107] As briefly described, in a solution of the present disclosure, a channel state information (CSI) reporting is configured. The UE starts, based on the configuration, at least one measurement (e.g., a CSI measurement) based on at least one reference signal without reporting the result of the at least one measurement to a first cell including a serving cell of the UE or a cell providing the configuration. FIG. 3 illustrates an example signalling flow 300 for channel state information measurement for candidate cell in accordance with some example embodiments of the present disclosure.

[0108] The signaling flow 300 involves the first apparatus 110 and the second apparatus 120 in FIG. 1 A and FIG. IB. Moreover, the signaling flow 300 involves a source DU 310, a source CU 320, and a target DU 330. The source DU 310 and the source CU 320 may be included in the second apparatus 120. In some implementations, the target DU 330 may be included in the second apparatus 120. Additionally, the target DU 330 may be considered as an implementation of the target candidate cell of the cell switch. As used herein, the term “target candidate cell” may also be referred to as a “target cell”. The target candidate cell may become a new serving cell after the cell switch. The previously serving cell (that is, the currently serving cell before the cell switch) may become a candidate cell after the cell switch. The serving cell before the cell switch may be referred to as a “source cell”.

[0109] In operation, the second apparatus 120 transmits (3050), to the first apparatus 110, a configuration regarding a channel state information (CSI) reporting. The configuration includes at least one reference signal for at least one measurement for CSI of at least one candidate cellfor a cell switch or mobility. Furthermore, the configuration (also referred to as “CSI reporting configuration” or “reporting configuration”) indicates the at least one measurement without reporting a result of the at least one measurement to a first cell. In these cases, the first cell includes a serving cell of the first apparatus 110 or a cell providing the configuration. Correspondingly, the first apparatus 110 receives the configuration. Additionally, the configuration may include a RRC configuration.

[0110] Furthermore, the first apparatus 110 performs (3070 / 3090 / 3110 / 3130), based on the configuration, the at least one measurement based on the at least one reference signal without reporting the result of the at least one measurement to the first cell. Specifically, the CSI reporting configuration type may be periodic, semi-persistent on PUCCH, semi-persistent on PUSCH, aperiodic, or event triggered reporting. As used herein, the measurement without being reported to the first cell may be referred to as a “no reported measurement” or “limited reported measurement” or “LTM CSI acquisition measurement” or “LTM CSI acquisition”.[OHl] In some embodiment, an indication may be configured associated with the CSI report configuration for the first apparatus 110 to perform the CSI acquisition measurements using the CSI-RSs (associated with the report configuration). The configuration may cause the first apparatus 110 to determine that the measurements are not reported to the current serving cell (alternatively to the cell where the reporting configuration is provided).

[0112] Specifically, for semi-persistent report on PUCCH, aperiodic or semi-persistent report on PUSCH (semiPersistentOnPUSCH) report configuration type, the first apparatus 110 may perform the measurements after the activation of reporting.

[0113] Additionally, the configuration may cause the first apparatus 110 to report the measurements to the target candidate cell (alternatively to the cell where the measurement RSs are located or the cell associated with the measurement RSs). In some following embodiments, the RSs may be described as CSI-RSs. It is to be understood that other suitable RSs may also be applied. Embodiments of the present disclosure is not limited here.

[0114] In some implementations, the first apparatus 110 may include a terminal device (e.g., a UE) and the second apparatus 120 may include a network device.

[0115] In some implementations, the configuration may include an indication with a first value. In these cases, the indication with the first value may indicate the at least one measurement without reporting a result of the at least one measurement to the first cell.

[0116] In some example embodiments, an explicit indication (e.g., one bit indication) associated with the report configuration may be used to trigger the UE to perform the CSI acquisition measurements using the CSI-RSs (associated with the report configuration). The UE may be configured not to report the said measurements to the current serving cell (alternatively to the cell where the reporting configuration is provided).

[0117] Specifically, If the value of the indication is set to the first value (e.g., 1), then the UE may not (alternatively the UE is configured not) report measurements associated with the report to the current serving cell. The configuration may indicate that UE is not configured to report the measurements to the current serving cell. The configuration may indicate that UE is configured report the measurements to the target candidate cell.

[0118] Furthermore, if there are any UL resources, associated with the current serving cell, for reporting are given, the UE may not use them.

[0119] Alternatively, if the value of the indication is set to the second value (e.g., 0), then the UE may report measurements associated with the report configuration to the current serving cell (using the UL resources given to the UE).

[0120] Alternatively, or in addition, the configuration may include a report quantity field with a quantity value. The report quantity field with the quantity value may indicate the at least one measurement without reporting the result of the at least one measurement to the first cell. Moreover, the quantity value may include, for example, but not limited to, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a layer indicator (LI), a rank indicator (RI), or a further value other than a reference signal received power (RSRP) field or signal to interference plus noise ratio (SINR) field.

[0121] In some implementations, an implicit indication may be used to configure the UE to perform the CSI acquisition measurements using the CSI-RSs (associated with the report configuration). The configuration may cause the UE to determine that the measurements are not reported to the current serving cell.

[0122] Specifically, if the reporting configuration is configured for LTM and the report quantity field configured for the reporting configuration (associated) is set to certain value, the reporting configuration may configure to the UE to perform the CSI acquisition measurements using the CSI-RSs (associated with the report configuration). The configuration may cause the UE to determine that the measurements are not reported to the current serving cell.

[0123] Furthermore, the certain value may include at least one of (CQI, PMI, RI, or / and LI). Moreover, the certain value may be quantity other than RSRP or SINR.

[0124] Furthermore, the type of CSI reporting may include, for example, but not limited to, a periodic CSI reporting, an aperiodic CSI reporting, a semi-persistent CSI reporting, or an event-triggered CSI reporting. In these cases, the CSI reporting may include a periodic or semi-persistent report on physical uplink control channel (PUCCH), and an absence of configuration information indicative of uplink resources for reporting at least one measurement result indicates the at least one measurement without reporting a result of the at least one measurement to the first cell.

[0125] In some example embodiments, if the reporting configuration is configured for LTM, and report config type field configured for the reporting configuration (associated) is set to periodic or semi-persistent report on PUCCH (semiPersistentOnPUCCH), the absence of any UL resources (PUCCH resources) may cause the UE to determine that the measurements are not reported to the current serving cell.

[0126] In some example embodiments, the configuration may include a configuration of the first cell, or a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration. For instance, the CSI reporting configuration may be given under the current serving cell configuration (under CSI-MeasConfig given under ServignCellConfig). Additionally, the CSI reporting configuration may be a mobility (LTM) CSI reporting configuration. In other words, the CSI reporting configuration may be provided as a part of the current serving cell configuration. In some examples, the CSI reporting configuration may be provided as a part of a candidate cell configuration. In some examples, the CSI reporting configuration may be provided as a part of LTM configuration outside of any cell configuration.

[0127] Moreover, the configuration may be associated with layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) based on at least one of: an LTM reporting configuration identifier, or an LTM resource configuration for the at least one measurement. Specifically, the CSI reporting configuration may be associated with LTM based on the configuration identifier (e.g., the LTM reporting configuration identifier) or determined based on the configured (LTM) resource configuration for measurements.

[0128] Furthermore, the result of the at least one measurement may include, for example, but not limited to, a channel quality indicator (CQI), a precoding matrix indicator (PMI), a channelstate information reference signal (CSI-RS) resource indicator (CRI), a synchronization signal and physical broadcast channel (SS / PBCH) block resource indicator (SSBRI), a layer indicator (LI), or a rank indicator (RI). In some implementations, report quantity associated with the CSI reporting configuration may indicate one or more of CQI, PMI, CRI, SSBRI), LI, or RI. For example, CSI measurements (also referred to as “CSI acquisition measurements”) may refer to the measurements to derive one or more of CSI quantities such as CQI, PMI, CRI, SSBRI, LI, RI, Ll-RSRP, Ll-SINR, Capabilityindex or time-domain channel properties (TDCP).

[0129] In some example embodiments, the configuration may indicate which report quantity is included in the result of the at least one measurement. The first apparatus 110, upon the reception of indication, may start measuring the indicated CSLRSs for the configured reporting quantities.

[0130] Moreover, at 3120, the first apparatus 110 may receive, from the second apparatus 120, a command for a cell switch to a target candidate cell (e.g., the target DU 330). The command may indicate the target candidate cell and a transmission configuration indication (TCI) state associated with the target candidate cell. In these cases, at 3130, the first apparatus 110 may perform a measurement associated with the target candidate cell or the TCI state. In other words, the first apparatus 110 may perform CSI measurements on CSLRSs configured for the target candidate cell. In some examples, the first apparatus 110 may perform CSI measurements which associated with the indicated TCI state. Specifically, the first apparatus 110 may perform CSI measurements using one or more CSLRSs which are quasi co-location (QCL) RS configured for the TCI state or have QCL relation (i.e., QCLed with respect to one of the QCL type, e.g., QCL typeA, typeB, typeC, or typed) with respect to RS configured for the TCI state configuration or have QCL relation with respect to a RS QCLed with the RS configured for the TCI state configuration. As illustrated, at 3120, the second apparatus 120 may transmit, to the first apparatus 110, MAC CE triggering cell change. The MAC CE may include a target candidate cell identification (ID) and an indicated TCI state. Furthermore, at 3130, the first apparatus 110 may continue measurements associated with only the target candidate cell (e.g., the target DU 330) and / or the indicated TCI state.

[0131] Additionally, at 3140, when a cell switch to the target candidate cell being performed, the first apparatus 110 may transmit the result of the at least one measurement to the target candidate cell (e.g., the target DU 330) or a candidate cell associated with the at least one reference signal for the at least one measurement. In these cases, when receiving the command,the first apparatus 110 may stop a measurement on a candidate cell different from the target candidate cell or a measurement on a reference signal not associated with the TCI state. Specifically, the first apparatus 110 may stop CSI measurements using one or more CSI-RSs which are not QCL RS configured for the TCI state or do not have any QCL relation (i.e., QCLed with respect to one of the QCL type, e.g., QCL typeA, typeB, typeC, or typed) with respect to RS configured for the TCI state configuration or do not have any QCL relation with respect to a RS QCLed with the RS configured for the TCI state configuration.

[0132] In some example embodiments, the UE may be triggered to make measurements before the reception of the cell switch command. For instance, the first apparatus 110 may receive, from the second apparatus 120, a message for an activation of a candidate transmission configuration indication (TCI) state. Moreover, the first apparatus 110 may stop a measurement on the at least one reference signal for CSI for at least one candidate cell without an activated TCI. For example, upon the reception of the cell switch command, the first apparatus 110 may stop measurements on candidate cells not indicated in the cell switch command. Upon the reception of the (early) candidate TCI state activation, the first apparatus 110 may stop measurements on at least one CSLRS for CSI acquisition for candidate cells for which the TCI is not activated. Specifically, the first apparatus 110 may stop perform CSI measurements using one or more CSI-RSs which are not the QCL RS configured for any active TCI state or do not have QCL relation with respect to RS configured for any active TCI state configuration or do not have QCL relation with respect to a RS QCLed with the RS configured for any active TCI state configuration.

[0133] Furthermore, the first apparatus 110 may perform at least one physical random access channel (PRACH) transmission for an early uplink synchronization. Additionally, the first apparatus 110 may stop a measurement on the at least one reference signal for CSI for at least one candidate cell without being performed the early uplink synchronization. For example, Upon the performing at least one PRACH transmission for early UL sync, the first apparatus 110 may stop measurements on at least one CSLRS for CSI acquisition for candidate cells for which the early UL sync is not performed. For example, the first apparatus 110 may stop perform CSI measurements using CSI-RSs which are not associated (e.g., in terms of QCL relation) with the RS (e.g., SSB or CSLRS) used for early uplink synchronization, e.g., RS used for UE-based timing advance estimation, specially to derive the receive timing difference or for random access channel based early uplink synchronization, the RS used to determine the random access channel occasion or / and preamble sequence selection for preamble transmission .Upon the reception of the cell switch command, the first apparatus 110 may stop measurements on RSs not associated with the indicated TCI state(s) in the cell switch command.

[0134] In some example embodiments, the first apparatus 110 may transmit, to the second apparatus 120, for example, but not limited to, a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell or a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch. Specifically, the first capability or the second capability may include the maximum number of cells or reference signals for which the at least one measurement is performed, or the maximum number of cells or reference signals for which the at least one measurement is performed within a time duration. Correspondingly, the second apparatus 120 may receive, from the first apparatus 110, the first capability and / or the second capability.

[0135] In some implementations, for example, the first apparatus 110 may indicate a capability to support CSI acquisition measurements before the cell switch for CSI acquisition for mobility candidate cells. In these cases, the capability may indicate the number of maximum cells / RSs the UE may perform CSI acquisition measurements. The capability may indicate the number of maximum cells / RSs the UE may perform CSI acquisition measurements withing a given time (e.g., a slot, a subframe, a frame, or, a Transmission Time Interval or any other suitable time length). Moreover, the first apparatus 110 may indicate a separate capability to support CSI acquisition CSI acquisition measurements during the cell switch (or after receiving the cell switch command) for CSI acquisition for mobility candidate cells. Specifically, the capability may indicate the number of maximum cells / RSs the UE may perform CSI acquisition measurements. The capability may indicate the number of maximum cells / RSs the UE may perform CSI acquisition measurements withing a given time (e.g., a slot, a subframe, a frame, or, a Transmission Time Interval or any other suitable time length).

[0136] As illustrated in FIG. 3, at 3060, after receiving the RRC reconfiguration, the first apparatus 110 may transmit a RRC reconfiguration complete message to the second apparatus 120. Specifically, the RRC reconfiguration may be transmitted to the source CU 320. As mentioned above, at 3070, if the CSI reporting configuration type is periodic associated with periodic CSI-RSs, the first apparatus 110 may perform periodic measurement on associated CSI-RSs without reporting to the current serving cell (e.g., the source DU 310).

[0137] Moreover, at 3080, the second device 120 may transmit, to the first apparatus 110, DLcontrol command (e.g., MAC CE) triggering SP report. In these cases, if the CSI reporting configuration type is SP CSI report via PUCCH (e.g., associated with periodic CSI-RSs), at 3090, the first apparatus 110 may perform measurement on associated CSI-RSs without reporting to current serving cell (e.g., source DU 310).

[0138] In some implementations, at 3100, the second apparatus 120 may transmit, to the first apparatus 110, DL control command (e.g., DCI) triggering SP or AP CSI report. In these cases, if the reporting configuration type is AP or SP CSI report via PUSCH (e.g., associated with periodic CSI-RSs), at 3110, the first apparatus 110 may perform measurement on associated CSI-RSs without reporting to the current serving cell (e.g., the source DU 310).

[0139] In some embodiment, as illustrated in FIG. 3, at 3010, the first apparatus 110 may transmit measurement report to the second apparatus 120. Specifically, the measurement report may be transmitted to the source DU 310 in the second apparatus 120. Moreover, at 3020, the source DU 310 may transmit, to the source CU 320, an UL RRC message with L3 measurement report. At 3030, the second apparatus 120 may perform LTM candidate preparation. Specifically, at 3040, the source CU 320 in the second apparatus 120 may determine LTM configuration. The LTM configuration may include, for example, but not limited to, LTM measurement configuration including P CSI-RSs for CSI acquisition from the target DU 330. Moreover, the LTM configuration may include LTM report configuration (e.g., in each cell configuration), CSI report configuration, and an indication for no reporting to the current serving cell (e.g., source DU 310).

[0140] In this way, measurements may be triggered without reporting to the current serving cell. Thus, the efficiency and effectiveness of the cell switch may be improved.

[0141] Regarding the LI measurement configuration in LTM of Rel-18, information about measurement resources (SSBs) from LTM candidate cells may be provided to the UE so that UE may make measurements. The UE may be also configured with LI measurement reporting configuration where the UE may report the measurements. For LTM, periodic and semi- persistent report on PUCCH, semi-persistent report on PUSCH, and aperiodic report on PUSCH may be supported.

[0142] Reference is made to FIG. 4, which illustrates a schematic diagram 400 of an example of LTM CSI reporting configuration in accordance with some example embodiments of the present disclosure. In the embodiment of FIG. 4, the UE may be configured with one or moreLTM CSI reporting configurations (LTM-CSI-ReportConfig) where each reporting configuration includes an LTM CSI resource configuration (LTM-CSI-ResourceConfig) including the information of resources to be used for channel measurements (Ll-RSRP measurements). For each reporting configuration, the UE may be configured to report M RSs / beams from each of the L configured candidate cells. I.e., each LTM CSI Resource Setting (LTM-CSI-ResourceConfig) may include configuration of an LTM-CSI-SSB-ResourceSet which includes a list of Z > 1 SS / PBCH blocks indices (given by Itm-CSI-SSB-ResourceLisf) and a list of Z LTM-Candidatelds (given by Itm-CandidatelDLisf) referring to candidate cells associated with the SS / PBCH block indices.

[0143] Reference is made to FIG. 5, which illustrates a schematic diagram 500 of an example of LTM configuration in accordance with some example embodiments of the present disclosure. Main components of Rel-18 LTM configuration and the positions of the components are illustrated in FIG. 5. Specifically, a high level view of LTM configuration given in RRC is shown in FIG. 5.

[0144] In the embodiment of FIG. 5, for each candidate cell, the UE may determine the time domain behavior of a SS / PBCH block resource from ssb-Periodicity and ssb-PositionsInBurst. Moreover, the frequency domain behavior of a SS / PBCH block resource may be determined by the higher layer parameters subCarrierSpacing, ssbFrequency.

[0145] Specifically, for each cell, LTM CSI report configurations may be given under current serving cell’s configuration where each report configuration contains an indication of a LTM CSI resource configuration and other parameters related for reporting, e.g., timing and uplink resources to transmit reports.

[0146] Furthermore, an LTM CSI resource configuration may contain a set of SSB indices from multiple candidate cells, which may be placed in a common LTM configuration, i.e., in LTM-configuration.

[0147] In some example embodiments, the detailed configuration of each SSB of a candidate cell indicated in an LTM CSI resource configuration given in LTM-SSB-configuration under LTM-candidate information element (IE). For each candidate cell, LTM-Candidate IE may include the configuration / information which is needed by the UE before the cell switch, e.g., SSB information for LTM measurements.

[0148] The LTM-Candidate IE may also include the list of non-zero power (NZP)-CSLRSresources which are currently used to provide the information for activation of TCI states associated with tracking RS (a type of CSI-RS). The same may be extended for LTM measurements with CSI-RSs.

[0149] In some implementations, an LTM-Candidate IE may also include RRC container (ServingCellConfig) which contains all the configuration details that will be needed by the UE after UE moves to this candidate cell after the cell switch from the current serving cell. In other words, ServingCellConfig given under LTM-Candidate IE may include the configuration details needed to perform regular serving cell operation within the candidate cell.

[0150] Furthermore, information elements details of LTM-CSI-ReportConfig, LTM-CSL ResourceConfig, and LTM-CSLSSB-ResourceSet are given below in Table 1. These details are for SSB based measurement and reporting and are for illustration purpose. A similar framework may be used for CSI-RS based measurements and reporting. ServingCell of current serving cell may include CSI-MeasConfig IE which includes the set of - LTM-CSI-ReportConfig via Itm- CSI-ReportConfigToAddModList-rl8. The CSI-MeasConfig information element is shown below in Table 2. It is to be understood the parameters, the values and the IES in Table 1 and any other following tables are only for the purpose of illustration, without suggesting any limitation. Those parameters, values or IEs may be varied in some example embodiments. Scope of embodiments of the present disclosure is not limited here.Table 1 : ServingCellConfig information elementTable 2: CSI-MeasConfig information element

[0151] Furthermore, the IE LTM-CSI-ReportConfig may be used to configure report on the cell in which the LTM-CSI-ReportConfig is included. The LTM-CSI-ReportConfig information element is shown in Table 3.Table3 : LTM-CSI-ReportConfig information element

[0152] Specifically, for LTM-CSI-ReportConfig field, the Itm-CSI-ReportConfigld is used to identify an LTM-CSI-ReportConfig. The Itm-ReportContent is used to define the content of the LTM LI measurement report. The Itm-ResourcesForChannelMeasurement may indicate the resources used for LTM LI measurements. The pucch-CSI-ResourceList may indicate which PUCCH resource to use for reporting on PUCCH. The reportConfigType may be used to describe the time domain behavior of how the LI measurements for LTM are reported. The reportSlotConfig may represent periodicity and slot offset. The reportSlotOffsetList, reportSlotOffsetListDCI-O-1 , and reportSlotOffsetListDCI-O-2 may be timing offset Y for semi persistent reporting using PUSCH and aperiodic reporting.

[0153] Moreover, for LTM-ReportContent field, the nrOfiReportedCells may be used to define how many cells are reported within a single LI measurement report instance. The nrOfReportedRS-PerCell may be used to define how many RSs per cell are reported within a single LI measurement report instance. The spCelllnclusion may be used to indicate whether the UE shall include a LI measurement report associated to the current SpCell. Additionally, this field may only be configured if the current SpCell is configured as an LTM candidate cell.

[0154] Furthermore, the IE LTM-CSI-ReportConfigld may be used to identify an LTM-CSI- ReportConfig. The LTM-CSI-ReportConfigldmiormsdion element is shown in Table 4.Table 4: LTM-CSI-ReportConfigldmiormsdion element

[0155] Additionally, the IE LTM-CSI-ResourceConfig may be used to define a group of one or more CSI resources for one or more LTM candidate configurations. The LTM-CSI- ResourceConfig information element is shown in Table 5.Table 5: LTM-CSI-ResourceConfig information element

[0156] Specifically, for LTM-CSI-ResourceConfig field, the Itm-CSI-ResourceConfigld may be used to identify an instance of LTM-CSI-ResourceConfig IE. The Itm-CSI-SSB-ResourceSet may be used to define one SS / PBCH block resource set from one or more LTM candidate cells.

[0157] For LTM-CSI-SSB-ResourceSet field, the Itm-CandidateldList may be used to indicate the LTM candidate cell IDs related to the SSBs in the Itm-CSI-SSB-ResourceList. The list may have the same number of entries as Itm-CSI-SSB-ResourceList . The Itm-CSI-SSB-ResourceList may be used to indicate on SS / PBCH block resources from one or more LTM candidate cells. The Itm-CSI-SSB-ResourceSetld may be used to identify on SS / PBCH block resource set.

[0158] Moreover, the IE LTM-CSI-ResourceConfigld may be used to identify an LTM-CSI- ResourceConfig. The LTM-CSI-ResourceConfigldmio m^Bon element is shown in Table 6.Table 6: LTM-CSI-ResourceConfigldmio m^ticin elementI — ASN1START I

[0159] Furthermore, the LTM Config IE may be provided as shown, the LTM Config IE may include LTM-candidate for each candidate cell, where LTM-Candidate includes candidate configuration given by Itm-CandidateConfig and some information outside of Itm- CandidateConfig, e.g., information related to early U1 synch, TCI states, etc. which are used by the UE before the cell switch. The UE may not be able to decode the content of Itm- CandidateConfig before the cell switch.

[0160] Reference is made to FIG. 6, which illustrates an example signalling flow 600 for channel state information measurement for candidate cell in accordance with some example embodiments of the present disclosure.

[0161] The signaling flow 600 involves the first apparatus 110 and the second apparatus 120 in FIG. 1 A and FIG. IB. Moreover, the signaling flow 600 involves a source DU 610, a source CU 620, and a target DU 630. The source DU 610 and the source CU 620 may be included in the second apparatus 120. In some implementations, the target DU 630 may be included in the second apparatus 120. Additionally, the target DU 630 may be considered as an implementation of the target candidate cell of the cell switch.

[0162] In some implementations, the first apparatus 110 may include a terminal device (e.g., a UE) and the second apparatus 120 may include a network device.

[0163] In operation, the second apparatus 120 transmits (6050), to the first apparatus 110, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility. Correspondingly, the first apparatus 110 receives the configuration from the second apparatus 120. The CSI reporting configuration may be provided as a part of the current serving cell configuration. In some example embodiments, the CSI reporting configuration may be provided as a part of a candidate cell configuration. In some examples, the CSI reporting configuration may be provided as a part of LTM configuration outside of any cell configuration.

[0164] Furthermore, the second apparatus 120 transmits (6070 / 6090), to the first apparatus 110, a message for triggering the CSI reporting. Specifically, the message may indicate the atleast one measurement without reporting a result of the at least one measurement to a first cell. The first cell may include at least one of: a serving cell of the first apparatus or a cell providing the configuration. Correspondingly, the first apparatus 110 receives the message from the second apparatus 120.

[0165] Moreover, the first apparatus 110 performs (6080 / 6100 / 6120) based on the message, the at least one measurement based on the at least one reference signal without reporting the result of the measurement to the first cell.

[0166] Furthermore, a reserved bit in the message may indicate the at least one measurement without reporting the result to the first cell. The CSI reporting may include a semi-persistent CSI report via PUCCH. Additionally, the message may include a MAC CE triggering the SP CSI report. In some example embodiments, a logical channel identifier (LCID) in an MAC subheader of the MAC CE indicates that the first apparatus may be configured not to report the result to the first cell. In some implementations, the CSI reporting may include, for example, but not limited to, an aperiodic CSI report via PUSCH or a semi-persistent CSI report via PUSCH. The message may include DCI triggering AP CSI report and / or SP CSI report.

[0167] In some example embodiments, for report configuration type which are activated or triggered via layer 1 or layer 2 signaling (MAC-CE or DCI), i.e., semi-persistent report on PUCCH via MAC-CE (SP CSI reporting on PUCCH Activation / Deactivation MAC CE), aperiodic report on PUSCH via DCI (DCI formats for scheduling of PUSCH containing CSI request field, DCI scrambled with C-RNTI), semi-persistent report on PUSCH via DCI (DCI formats for scheduling of PUSCH containing CSI request field, DCI scrambled with SP-CS- RNTI), the corresponding layer 1 or layer 2 signaling may contain the indication. A reserved bit in the above MAC-CE and DCI may be used for this purpose.

[0168] Alternatively, MAC-CE (i.e., SP CSI reporting on PUCCH Activation / Deactivation MAC CE), a unique logical channel ID (LCID) or a unique extended LCID (eLCID) may be used in MAC subheader to uniquely identify that this MAC CE is to trigger the first apparatus 110 to perform the CSI acquisition measurements and the first apparatus 110 is configured not to report the said measurements to the current serving cell.

[0169] In addition, an absence of information indicative of uplink resources in the DCI for reporting at least one measurement may indicate that the result is not reported to the first cell. For instance, if the reporting configuration is configured for LTM, and report configurationtype field configured for the reporting configuration (associated) is set to aperiodic or semi- persistent report on PUSCH (semiPersistentOnPUSCH), lower layer signaling (DCI formats for scheduling of PUSCH containing CSI request field) triggering the reporting without any UL resources (UL grant) may cause the first apparatus 110 to determine that the measurements are not reported to the current serving cell (e.g., the source DU 610).

[0170] In some example embodiments, the configuration may be associated with layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) based on an LTM reporting configuration identifier and / or an LTM resource configuration for the at least one measurement. Specifically, the CSI reporting configuration may be associated with LTM based on the configuration identifier (e.g., the LTM reporting configuration identifier) or determined based on the configured (LTM) resource configuration for measurements.

[0171] Furthermore, the result of the at least one measurement may include, for example, but not limited to, a CQI, a PMI, a CRI, a SSBRI, a LI, or a RI. In some implementations, report quantity associated with the CSI reporting configuration may indicate one or more of CQI, PMI, CRI, SSBRI), LI, or RI. For example, CSI measurements (also referred to as “CSI acquisition measurements”) may refer to the measurements to derive one or more of CSI quantities such as CQI, PMI, CRI, SSBRI, LI, RI, Ll-RSRP, Ll-SINR, Capabilityindex or time-domain channel properties (TDCP).

[0172] Moreover, at 6110, the first apparatus 110 may receive, from the second apparatus 120, a command for a cell switch to a target candidate cell (e.g., the target DU 630). The command may indicate the target candidate cell and a transmission configuration indication (TCI) state associated with the target candidate cell. In these cases, at 6120, the first apparatus 110 may perform a measurement associated with the target candidate cell or the TCI state. In other words, the first apparatus 110 may perform CSI measurements on CSLRSs configured for the target candidate cell. In some examples, the first apparatus 110 may perform CSI measurements which associated with the indicated TCI state. Specifically, the first apparatus 110 may perform CSI measurements using one or more CSLRSs which are quasi co-location (QCL) RS configured for the TCI state or have QCL relation (i.e., QCLed with respect to one of the QCL type, e.g., QCL typeA, typeB, typeC, or typed) with respect to RS configured for the TCI state configuration or have QCL relation with respect to a RS QCLed with the RS configured for the TCI state configuration. As illustrated, at 6110, the second apparatus 120 may transmit, to the first apparatus 110, MAC CE triggering cell change. The MAC CE may include a targetcandidate cell identification (ID) and an indicated TCI state. Furthermore, at 6120, the first apparatus 110 may continue measurements associated with only the target candidate cell (e.g., the target DU 630) and / or the indicated TCI state.

[0173] Additionally, at 6130, when a cell switch to the target candidate cell being performed, the first apparatus 110 may transmit the result of the at least one measurement to the target candidate cell (e.g., the target DU 630) or a candidate cell associated with the at least one reference signal for the at least one measurement. In these cases, when receiving the command, the first apparatus 110 may stop a measurement on a candidate cell different from the target candidate cell or a measurement on a reference signal not associated with the TCI state. Specifically, the first apparatus 110 may stop CSI measurements using one or more CSI-RSs which are not QCL RS configured for the TCI state or do not have any QCL relation (i.e., QCLed with respect to one of the QCL type, e.g., QCL typeA, typeB, typeC, or typed) with respect to RS configured for the TCI state configuration or do not have any QCL relation with respect to a RS QCLed with the RS configured for the TCI state configuration.

[0174] In some example embodiments, the UE may be triggered to make measurements before the reception of the cell switch command. For instance, the first apparatus 110 may receive, from the second apparatus 120, a message for an activation of a candidate transmission configuration indication (TCI) state. Moreover, the first apparatus 110 may stop a measurement on the at least one reference signal for CSI for at least one candidate cell without an activated TCI. For example, upon the reception of the cell switch command, the first apparatus 110 may stop measurements on candidate cells not indicated in the cell switch command. Upon the reception of the (early) candidate TCI state activation, the first apparatus 110 may stop measurements on at least one CSLRS for CSI acquisition for candidate cells for which the TCI is not activated. Specifically, the first apparatus 110 may stop perform CSI measurements using one or more CSI-RSs which are not the QCL RS configured for any active TCI state or do not have QCL relation with respect to RS configured for any active TCI state configuration or do not have QCL relation with respect to a RS QCLed with the RS configured for any active TCI state configuration.

[0175] Furthermore, the first apparatus 110 may perform at least one physical random access channel (PRACH) transmission for an early uplink synchronization. Additionally, the first apparatus 110 may stop a measurement on the at least one reference signal for CSI for at least one candidate cell without being performed the early uplink synchronization. For example,Upon the performing at least one PRACH transmission for early UL sync, the first apparatus 110 may stop measurements on at least one CSI-RS for CSI acquisition for candidate cells for which the early UL sync is not performed. For example, the first apparatus 110 may stop perform CSI measurements using CSLRSs which are not associated (e.g., in terms of QCL relation) with the RS (e.g., SSB or CSI-RS) used for early uplink synchronization, e.g., RS used for UE-based timing advance estimation, specially to derive the receive timing difference or for random access channel based early uplink synchronization, the RS used to determine the random access channel occasion or / and preamble sequence selection for preamble transmission. Upon the reception of the cell switch command, the first apparatus 110 may stop measurements on RSs not associated with the indicated TCI state(s) in the cell switch command.

[0176] In some example embodiments, the first apparatus 110 may transmit, to the second apparatus 120, for example, but not limited to, a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch. The first capability or the second capability may include the maximum number of cells or reference signals for which the at least one measurement is performed and / or the maximum number of cells or reference signals for which the at least one measurement is performed within a time duration. Correspondingly, the second apparatus 120 may receive the first capability and / or the second capability.

[0177] In this way, measurements may be triggered by the message from the second apparatus without reporting to the current serving cell. Thus, the flexibility and effectiveness of the cell switch may be improved.

[0178] As mentioned, in a further solution, a second apparatus such as a network device transmits, to a first apparatus such as a terminal device, a configuration of a set of RSs for measurements of at least one candidate cell for a cell switch or mobility such as LTM. The second apparatus further transmits, to the first apparatus, a message indicating at least one RS of the set of RSs. The message further indicates to perform at least one measurement on the at least one reference signal for CSI of the at least one candidate cell without reporting a result of the at least one measurement to a serving cell of the first apparatus and / or a cell providing the message. The first apparatus thus performs the measurement without reporting the measurement result to the serving cell and / or the cell providing the message. In this way, the first apparatus may be informed of whether a measurement of a RS needs to be reported to aserving cell or a candidate cell. The first apparatus may acquire and report the CSI parameters such as CQI, PMI, RI, or / and LI for a candidate cell, which then may be used for the transmission / reception in the target cell after the cell switch. The LTM can thus be enhanced.

[0179] FIG. 7 illustrates a signaling flow 700 for CSI measurement for candidate cell procedure according to some example embodiments of the present disclosure. The signaling flow 700 involves the first apparatus 110 and the second apparatus 120 in FIG. 1A and FIG. IB.

[0180] In operation, the second apparatus 120 transmits (7010), to the first apparatus, a configuration of a set of reference signals for measurements of at least one candidate cell for a cell switch or mobility. The first apparatus 110 receives (7020) the configuration. The configuration may be a configuration for a candidate cell, and / or a configuration for mobility such as LTM. The set of RSs may be a set of CSI RSs or any other suitable RSs. The configuration may be similar to those described with respect to FIG. 4 and FIG. 5, which will not be repeated here.

[0181] The second apparatus 120 transmits (7030) a message to the first apparatus 110. The first apparatus 110 receives (7040) the message. The message indicates at least one reference signal of the set of reference signals. In other words, the message includes information of the at least one RS. The message further indicates to perform at least one measurement on the at least one reference signal for CSI of the at least one candidate cell without reporting a result of the at least one measurement to a first cell. The first cell may be a serving cell of the first apparatus 110 and / or a cell providing the configuration or the message. For example, the measurement may be indicated to not be reported to the currently serving cell and / or the cell providing the configuration or the cell providing the message.

[0182] In some example embodiments, the message may include at least one of a time type of the at least one reference signal, the time type being periodic, aperiodic or semi-persistent, an identifier of a resource set comprising the at least one reference signal, the resource set being configured for a cell switch, an identifier of a resource set associated with LTM CSI acquisition, an identifier of a report configuration associated with the LTM CSI acquisition, at least one identifier of the at least one reference signal, or information of the at least one candidate cell.

[0183] By way of example, the result of the at least one measurement may include at least one of the following report quantities: a CQI, a PMI, CRI, SSBRI, LI, or a RI. Which report quantitymay be included in the measurement result (or the measurement report) or which report quantity need to be excluded from the measurement result may be configured in the configuration or configured by a further configuration.

[0184] The information of RS may be information of CSI-RS(s) associated with one or more candidate cells. The CSI-RS may be periodic, aperiodic or semi-persistent CSI-RS. The type of the CSI-RS may also be indicated by the message.

[0185] In some example embodiments, the RS information may comprise a resource set ID where resource set is configured as a part of the cell switch configuration, containing RSs IDs associated with one or more candidate cells (e.g., LTM-CSI-ResourceConfig). For example, the information may comprise a codepoint that indicates the at least one of: resource set ID associated with LTM CSI acquisition, or report config ID associated with LTM CSI acquisition.

[0186] As another example, the information may comprise RS IDs (or RS set ID or RS config Id) and associated candidate cell information, explicitly, e.g., candidate config ID(s), or implicitly. The RSs given in the message may be periodic or semi-persistent or aperiodic CSI- RS(s).

[0187] The first apparatus 110 performs (7050), based on the message, the at least one measurement without transmitting the result to the first cell. That is, the first apparatus 110 measures the at least one reference signal indicated by the message. The at least one reference signal may be associated with at least one candidate cell. That is, the first apparatus 110 may measure CSI for the at least one candidate cell. Such measurement result may not be reported to the first cell.

[0188] In some example embodiments, in response to receiving (7040) the message, the first apparatus 110 may perform (7050) the at least one measurement without transmitting the result to the first cell. Alternatively, or in addition, in some example embodiments, the first apparatus 110 may transmit an acknowledgement of the message to the second apparatus 120. In response to transmitting the acknowledgement of the message, the first apparatus 110 may perform (7050) the at least one measurement without transmitting the result to the first cell. As used herein, performing an operation such as the measurement without reporting in response to receiving a message may be explained as perform the operation in response to receiving the message or in response to transmitting an ACK of the message.

[0189] In some example embodiments, the message may be an MAC CE message, and / or DCI.As used herein, the message indicating the no reported measurement may be referred to as a command or a command message. The message may be a newly defined message such as layer one or layer two command or may be a reused command message such as cell switch command. The message may be used to trigger the first apparatus 110 to start performing the CSI acquisition measurements using one or more CSI-RSs associated with one or more candidate cells. The first apparatus 110 may be configured not to report the measurements to the current serving cell (alternatively to the cell where the control command is provided). By way of example, an explicit indication such as a reserved bit in the message (such as MAC CE or DCI) may indicate that the results of the at least one measurement is not reported to the first cell. The message may be used for an additional purpose or function, which will not be limited here.

[0190] In some example embodiments, the message may be an MAC CE for indicating an activation or deactivation of one or more semi-persistent reference signals for the at least one candidate cell. In response to receiving the MAC CE, the first apparatus 110 may perform (7050) the at least one measurement without transmitting the result to the first cell. In one example, a MAC-CE used to activate / deactivate SP CSI-RSs for a candidate cell may be used to trigger the first apparatus 110 to start performing the CSI acquisition measurements on the given CSI- RSs without any reporting of the measurements to the current serving cell. That is, the first apparatus 110 may not expect an activation of a SP CSI report or an aperiodic report associated with the SP CSI-RSs causing the first apparatus 110 to perform and report the measurement to the current serving cell.

[0191] In some example embodiments, the message may be transmitted before transmitting a cell switch command to the first apparatus 110. That is, the measurement may be performed before the cell switch. In some example embodiments, if the cell switch to a target candidate cell is performed after the at least one measurement, the first apparatus 110 may transmit the result of the at least one measurement to at least one of: the target candidate cell, or a candidate cell associated with the at least one reference signal for the at least one measurement. That is, the no reported measurement result may be later transmitted to the target candidate cell or the candidate cell associated with the RS.

[0192] Triggering of measurement may cause the first apparatus 110 to report the measurements to the target cell after the cell switch (alternatively to the cell where the measurement RSs are located or the cell associated with the measurement RSs).

[0193] The first apparatus 110 may start performing the measurements after the successful reception and processing of the control message (alternatively after the processing of the control message and transmitting the acknowledgment, HARQ-ACK, to the serving cell).

[0194] Alternatively, or in addition, the message may be a cell switch command indicating a cell switch to a target candidate cell. That is, the cell switch command message such as the MAC CE for cell switch or cell change may be used to indicate the no reported measurement. In such case, the at least one reference signal may be associated with at least one of the target candidate cell or TCI state in the cell switch command for handover. The first apparatus 110 may perform (7050) the at least one measurement based on the at least one reference signal during the cell switch or after the cell switch without reporting the result to the first cell. In some example embodiments, the first apparatus 110 may perform (7050) the at least one measurement based on spatial domain information obtained from the TCI state.

[0195] The cell switch command may contain the information of RSs, associated with the candidate ID and / or TCI state indicated in the cell switch command for handover. The first apparatus 110 may use to acquire the CSI acquisition measurement. For example, the first apparatus 110 may perform the measurements using the spatial domain information acquired from the indicated TCI state. The information may comprise a codepoint that indicates the at least one of resource set ID associated with LTM CSI acquisition, or report config ID associated with LTM CSI acquisition.

[0196] In some example embodiments, the RS for the measurement during or after the cell switch needs to be activated. In some example embodiments, the second apparatus 120 may transmit, to the target candidate cell, a notification of the cell switch, the notification indicating information of the at least one reference signal. The notification may indicate the target candidate cell to activate or start transmitting the at least one RS.

[0197] The information of RS in the cell switch command may be transmitted to the target candidate cell. This may particularly be used in case of semi-persistent or aperiodic CSLRSs associated with the target cell are indicated for CSI acquisition. The target candidate cell after receiving the cell switch notification, may activate / start transmitting the RSs, if not activated already.

[0198] In some example embodiments, the target candidate cell is associated with the second apparatus 120. That is, the second apparatus 120 may provide the target candidate cell andthe serving cell before the cell switch. As used herein, the serving cell before the cell switch is referred to as a “source cell”. In other words, the cell switch is an intra-gNB cell switch. For the intra-gNB cell switch, in response to receiving the notification at the target candidate cell, the second apparatus 120 may activate or start transmitting the at least one reference signal via the target candidate cell. The target candidate cell may activate or start transmitting the at least one RS.

[0199] Alternatively, in some example embodiments, the target candidate cell is associated with a third apparatus different from the second apparatus 120. That is, the source cell and the target candidate cell are associated with different gNBs. Such cell switch may be an inter- gNB cell switch. For the inter-gNB cell switch, the target candidate cell may receive the notification, and activate or start transmitting the at least one reference signal.

[0200] In some example embodiments, for the intra-gNB cell switch, the source cell is associated with a source DU, and the target candidate cell is associated with a target DU. The source DU and the target DU connects to a same CU. That is, the second apparatus 120 may include the CU, the source DU (also referred to as a first DU) controlling the source cell, and the target DU (also referred to as a second DU) controlling the target cell. In such scenario, the notification may be transmitted from the source DU to the CU. The CU may forward the notification to the target DU. The interface between the CU and the source or target DU may be Fl interface.

[0201] For the inter-gNB cell switch. The source DU controlling the source cell connects to a first CU (also referred to as a source CU). The target DU controlling the target candidate cell connects to a second CU (also referred to as a target CU). The second apparatus 120 may include the source DU and the source CU. A third apparatus may include the target DU and the target CU. In such scenario, the source DU may transmit the notification to the source CU for example via the Fl interface. The source CU may transmit the notification to the target CU for example via an Xn interface. The target CU may forward the notification to the target DU for example via the Fl interface.

[0202] In this way, the RS for the measurement during or after the cell switch can be transmitted. The CSI acquisition for target candidate cell can be achieved.

[0203] In some example embodiments, the first apparatus 110 may receive, from the second apparatus 120, a further message for an activation of a candidate TCI state. In response toreceiving the further message, the first apparatus 110 may stop a measurement on the at least one reference signal for CSI for at least one candidate cell without an activated TCI.

[0204] In some example embodiments, the first apparatus 110 may perform at least one PRACH transmission for an early uplink synchronization. The first apparatus 110 may stop a measurement on the at least one reference signal for CSI for at least one candidate cell without being performed the early uplink synchronization.

[0205] In some example embodiments, the first apparatus 110 may transmit, to the second apparatus 120, at least one of: a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch. The first capability or the second capability may include the maximum number of cells or reference signals for which the at least one measurement is performed, and / or the maximum number of cells or reference signals for which the at least one measurement is performed within a time duration. The second apparatus 120 may receive the first and / or second capability. In this way, the second apparatus 120 may be informed about how many cells or RS may be measured.

[0206] Several embodiments regarding the CSI measurement for candidate cell based on a message indicating the RS have been described with respect to FIG. 7. The signaling flow 800 in FIG. 8 illustrates further embodiments regarding such CSI measurement.

[0207] As shown, the signaling flow 800 involves a UE 810, a gNB 820 including a source DU 822 and a source CU 824, and a target DU 830. The target DU 830 may be included in the gNB 820 or be included in a different gNB (not shown). The UE 810 may be implemented as the first apparatus 110, and the gNB 820 may be implemented as the second apparatus 120. It is to be understood that several signaling or operations involved in the signaling flow 800 are same or similar with those of the signaling flow 300. Details of some same or similar signaling or operations will not be repeated here.

[0208] As shown, the source CU 824 may determine (8040) the LTM configuration for the UE 810. The LTM configuration may include LTM measurement configuration containing CSLRSs for CSI acquisition from the target DU 822. The LTM configuration such as RRC reconfiguration may be transmitted to UE 810.

[0209] In some example embodiments, for triggering measurement before the cell switch, thesource DU 822 may transmit a message or command to the UE 810 to trigger the measurement. In an example embodiment, the source DU 822 transmits (8070), to the UE 810, a layer one or layer two control command containing RS information for the CSI acquisition. The RS information may indicate CSI-RS(s) for measurements of at least one candidate cell. For example, the command may be MAC CE or DCI activating or deactivating a certain RS. In response to receiving the command, the UE 810 start performing (8080) the measurements on the indicated CSI-RS(s). The measurements may be periodic, aperiodic or semi-persistent. In addition, no reporting may be transmitted to the currently serving cell. After that, the source DU 822 may transmit (8090) an MAC CE command triggering the cell switch. The MAC CE command may indicate the target cell ID and indicated TCI state for the target cell. In response to receiving the MAC CE for cell change, the UE 810 may continue (8100) measurements associated with only the target candidate cell and / or the indicated TCI state. After the cell switch, the UE 810 may transmit (8110) a CSI report containing the CSI measurements on the indicted RS to the target DU 830.

[0210] Alternatively, in some example embodiments, the measurement may be triggered during the cell switch or after the cell switch. For example, for AP or SP CSI report via PUSCH, the message triggering the CSI acquisition measurements may be the command or MAC CE triggering the cell change. That is, the cell switch command (CSC) may indicate RS information for CSI acquisition measurement. For example, the source DU 822 transmits (8120) the cell switch command to the UE 810.

[0211] In some example embodiments, if SP or AP CSI-RSs are indicated in the cell switch command, the SP or AP CSI RSs may be activated by the target DU. In an embodiment, the source DU 822 may transmit (8130) a cell switch notification to the source CU 824, for example via Fl interface. The cell switch notification may indicate the SP or AP CSI-RSs. The source CU 824 may forward (8140) the cell switch notification to the target DU 830. For intra-gNB cell switch, the source CU 824 may forward (8140) the cell switch notification to the target DU 830 via Fl interface. For inter-gNB cell switch, the source CU 824 may transmit the cell switch notification to a target CU connecting the target DU 830 via Xn interface. The target CU may forward the cell switch notification to the target DU 830 via Fl interface.

[0212] In response to receiving the cell switch notification, the target DU 830 may activate (8150) or start transmission of the indicated SP or AP CSI-RSs. The UE 810 may start (8160) measurements associated with the indicated CSI-RSs. The UE 810 may transmit (8170) a CSIreport containing the CSI measurements to the target DU 830.

[0213] With the signaling flow 800, the L1 / L2 command message may trigger the CSI acquisition measurement without reporting. The LTM cell switch procedure can be enhanced.

[0214] It is to be understood that although some example embodiments are described with the intra-gNB cell switch for LTM and inter-gNB cell switch as examples, some example embodiments described with respect to these signaling flows may also be applicable for any other suitable mobility or any other suitable cell switch. Scope of embodiments of the present disclosure is not limited here.

[0215] It would be appreciated that some example specifications, signaling flows and embodiments are provided above, and the detailed description may be varied. It is to be understood that these signaling flows 300, 600, 700 and / or 800 may be used separately, or in any suitable combinations. Some example embodiments, operations or features described with respect to one of these signaling flows 300, 600, 700 and / or 800 may be applied to another of these signaling flows. Part of one of these signaling flows 300, 600, 700 and / or 800 may be applied in combination with part of another signaling flow. It is to be understood that these signaling flows 300, 600, 700 and / or 800 may involve any other suitable operations or signaling not shown. With these signaling flows and similar signaling flows for the CSI acquisition, the LTM-based cell switch procedure and other suitable cell switch procedure can be enhanced.

[0216] FIG. 9 shows a flowchart of an example method 900 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 900 will be described from the perspective of the first apparatus 110 in FIG. 3.

[0217] At block 910, the first apparatus 110 receives, from a second apparatus, a configuration regarding a channel state information (CSI) reporting, the configuration comprising at least one reference signal for at least one measurement for CSI of at least one candidate cell for a cell switch or mobility, wherein the configuration indicates the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus 110 or a cell providing the configuration.

[0218] At block 920, the first apparatus 110 performs, based on the configuration, the at least one measurement based on the at least one reference signal without reporting the result of the at least one measurement to the first cell.

[0219] In some example embodiments, the configuration may include at least one of: a configuration of the first cell, or a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration.

[0220] In some example embodiments, the configuration may be associated with layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) based on at least one of an LTM reporting configuration identifier, or an LTM resource configuration for the at least one measurement.

[0221] In some example embodiments, the result of the at least one measurement may include at least one of the following report quantities: a channel quality indicator (CQI), a precoding matrix indicator (PMI), a channel state information reference signal (CSLRS) resource indicator (CRI), a synchronization signal and physical broadcast channel (SS / PBCH) block resource indicator (SSBRI), a layer indicator (LI), or a rank indicator (RI).

[0222] In some example embodiments, the configuration may indicate which report quantity is included in the result of the at least one measurement.

[0223] In some example embodiments, the method 900 may further include: in response to a cell switch to a target candidate cell being performed, transmitting the result of the at least one measurement to at least one of: the target candidate cell, or a candidate cell associated with the at least one reference signal for the at least one measurement.

[0224] In some example embodiments, the method 900 may further include: receiving, from the second apparatus, a command for a cell switch to a target candidate cell, the command indicating the target candidate cell and a transmission configuration indication (TCI) state associated with the target candidate cell; and performing a measurement associated with at least one of: the target candidate cell, or the TCI state.

[0225] In some example embodiments, the method 900 may further include: in response to receiving the command, stopping at least one of: a measurement on a candidate cell different from the target candidate cell, or a measurement on a reference signal not associated with the TCI state.

[0226] In some example embodiments, the method 900 may further include: receiving, from the second apparatus, a message for an activation of a candidate transmission configuration indication (TCI) state; and stopping a measurement on the at least one reference signal for CSI for at least one candidate cell without an activated TCI.

[0227] In some example embodiments, the method 900 may further include: performing at least one physical random access channel (PRACH) transmission for an early uplink synchronization; and stopping a measurement on the at least one reference signal for CSI for at least one candidate cell without being performed the early uplink synchronization.

[0228] In some example embodiments, the configuration may include an indication with a first value, the indication with the first value indicating the at least one measurement without reporting a result of the at least one measurement to the first cell.

[0229] In some example embodiments, the configuration may include a report quantity field with a quantity value, the report quantity field with the quantity value indicating the at least one measurement without reporting the result of the at least one measurement to the first cell, wherein the quantity value comprises at least one of: a channel quality indicator (CQI), a precoding matrix indicator (PMI), a layer indicator (LI), a rank indicator (RI), or a further value other than a reference signal received power (RSRP) field or signal to interference plus noise ratio (SINR) field.

[0230] In some example embodiments, the type of CSI reporting may include at least one of: a periodic CSI reporting, an aperiodic CSI reporting, a semi-persistent CSI reporting, or an event-triggered CSI reporting.

[0231] In some example embodiments, the CSI reporting may include a periodic or semi- persistent report on physical uplink control channel (PUCCH), and an absence of configuration information indicative of uplink resources for reporting at least one measurement result indicates the at least one measurement without reporting a result of the at least one measurement to the first cell.

[0232] In some example embodiments, the method 900 may further include: transmitting, to the second apparatus, at least one of: a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of: thing maximum number of cells or reference signals for which the at least one measurement is performed, or thing maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

[0233] In some example embodiments, the first apparatus 110 may include a terminal deviceand the second apparatus comprises a network device.

[0234] FIG. 10 shows a flowchart of an example method 1000 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1000 will be described from the perspective of the second apparatus 120 in FIG. 3.

[0235] At block 1010, the second apparatus 120 transmits, to a first apparatus, a configuration regarding a channel state information (CSI) reporting, the configuration comprising at least one reference signal for at least one measurement for CSI of at least one candidate cell for a cell switch or mobility, wherein the configuration indicates the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration.

[0236] In some example embodiments, the method 1000 may further include: receiving, from the first apparatus, at least one of: a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of: thing maximum number of cells or reference signals for which the at least one measurement is performed, or thing maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

[0237] In some example embodiments, the configuration may include an indication with a first value, the indication with the first value indicating the at least one measurement without reporting a result of the at least one measurement to the first cell.

[0238] In some example embodiments, the configuration may include a report quantity field with a quantity value, the report quantity field with the quantity value indicating the at least one measurement without reporting a result of the at least one measurement to the first cell, wherein the quantity value comprises at least one of: a channel quality indicator (CQI), a precoding matrix indicator (PMI), a layer indicator (LI), a rank indicator (RI), or a further field other than a reference signal received power (RSRP) field or signal to interference plus noise ratio (SINR) field.

[0239] In some example embodiments, the CSI reporting may include at least one of: a periodic CSI reporting, an aperiodic CSI reporting, a semi-persistent CSI reporting, or an event-triggered CSI reporting.

[0240] In some example embodiments, the CSI reporting may include a periodic or semi- persistent report on physical uplink control channel (PUCCH), and an absence of configuration information indicative of uplink resources for reporting at least one measurement indicates the at least one measurement without reporting a result of the at least one measurement to the first cell.

[0241] In some example embodiments, the configuration may include a radio resource control configuration.

[0242] FIG. 11 shows a flowchart of an example method 1100 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1100 will be described from the perspective of the first apparatus 110 in FIG. 6.

[0243] At block 1110, the first apparatus 110 receives, from a second apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility.

[0244] At block 1120, the first apparatus 110 receives, from the second apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus 110 or a cell providing the configuration.

[0245] At block 1130, the first apparatus 110 performs, based on the message, the at least one measurement based on the at least one reference signal without reporting the result of the measurement to the first cell.

[0246] In some example embodiments, a reserved bit in the message may indicate the at least one measurement without reporting the result to the first cell.

[0247] In some example embodiments, the CSI reporting may include a semi-persistent (SP) CSI report via physical uplink control channel (PUCCH), and the message may include a medium access control control element (MAC CE) triggering the SP CSI report.

[0248] In some example embodiments, a logical channel identifier (LCID) in an MAC subheader of the MAC CE may indicate that the first apparatus 110 is configured not to report the result to the first cell.

[0249] In some example embodiments, the CSI reporting may include at least one of: an aperiodic (AP) CSI report via physical uplink shared channel (PUSCH) or a semi-persistent (SP) CSI report via PUSCH, and the message comprises downlink control information (DCI) triggering the at least one of: AP CSI report or SP CSI report.

[0250] In some example embodiments, an absence of information indicative of uplink resources in the DCI for reporting at least one measurement may indicate that the result is not reported to the first cell.

[0251] In some example embodiments, the configuration may be associated with layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) based on at least one of: an LTM reporting configuration identifier, or an LTM resource configuration for the at least one measurement.

[0252] In some example embodiments, the result of the at least one measurement may include at least one of the following report quantities: a channel quality indicator (CQI), a precoding matrix indicator (PMI), a channel state information reference signal (CSLRS) resource indicator (CRI), a synchronization signal and physical broadcast channel (SS / PBCH) block resource indicator (SSBRI), a layer indicator (LI), or a rank indicator (RI).

[0253] In some example embodiments, the first apparatus 110 may, in response to a cell switch to a target candidate cell being performed, transmit the result of the at least one measurement to at least one of: the target candidate cell, or a candidate cell associated with the at least one reference signal for the at least one measurement.

[0254] In some example embodiments, the first apparatus 110 may receive, from the second apparatus, a command for a cell switch to a target candidate cell, the command indicating the target candidate cell and a transmission configuration indication (TCI) state associated with the target candidate cell; and perform a measurement associated with at least one of: the target candidate cell, or the TCI state.

[0255] In some example embodiments, the first apparatus 110 may, in response to receiving the command, stop at least one of: a measurement on a candidate cell different from the target candidate cell, or a measurement on a reference signal not associated with the TCI state.

[0256] In some example embodiments, the first apparatus 110 may receive, from the second apparatus, a message for an activation of a candidate transmission configuration indication (TCI) state; and stop a measurement on the at least one reference signal for CSI for at least one candidate cell without an activated TCI.

[0257] In some example embodiments, the first apparatus 110 may perform at least one physical random access channel (PRACH) transmission for an early uplink synchronization; and stop a measurement on the at least one reference signal for CSI for at least one candidate cell without being performed the early uplink synchronization.

[0258] In some example embodiments, the first apparatus 110 may transmit, to the second apparatus, at least one of a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of thing maximum number of cells or reference signals for which the at least one measurement is performed, or thing maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

[0259] FIG. 12 shows a flowchart of an example method 1200 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1200 will be described from the perspective of the second apparatus 120 in FIG. 6.

[0260] At block 1210, the second apparatus 120 transmits, to a first apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility.

[0261] At block 1220, the second apparatus 120 transmits, to the first apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the configuration.

[0262] In some example embodiments, a reserved bit in the message may indicate the at least one measurement without reporting the result to the first cell.

[0263] In some example embodiments, the CSI reporting may include a semi-persistent (SP) CSI report via physical uplink control channel (PUCCH), and the message may include a medium access control control element (MAC CE) triggering the SP CSI report.

[0264] In some example embodiments, a logical channel identifier (LCID) in an MAC subheader of the MAC CE may indicate that the first apparatus is configured not to report the result to the first cell.

[0265] In some example embodiments, the CSI reporting may include at least one of: an aperiodic (AP) CSI report via physical uplink shared channel (PUSCH) or a semi-persistent (SP) CSI report via PUSCH, and the message comprises downlink control information (DCI) triggering the at least one of: AP CSI report or SP CSI report.

[0266] In some example embodiments, an absence of information indicative of uplink resources in the DCI for reporting at least one measurement may indicate that the result is not reported to the first cell.

[0267] In some example embodiments, the second apparatus 120 may receive, from the first apparatus, at least one of: a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of: thing maximum number of cells or reference signals for which the at least one measurement is performed, or thing maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

[0268] FIG. 13 shows a flowchart of an example method 1300 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1300 will be described from the perspective of the first apparatus 110 in FIG. 7.

[0269] At block 1310, the first apparatus 110 receives, from a second apparatus, a configuration of a set of reference signals for measurements of at least one candidate cell for a cell switch or mobility.

[0270] At block 1320, the first apparatus 110 receives, from the second apparatus, a message indicating at least one reference signal of the set of reference signals, the message further indicating to perform at least one measurement on the at least one reference signal for channel state information (CSI) of the at least one candidate cell without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus 110 or a cell providing the message.

[0271] At block 1330, the first apparatus 110 performs, based on the message, the at least one measurement without transmitting the result to the first cell.

[0272] In some example embodiments, the message may include at least one of: a mediumaccess control control element (MAC CE), or downlink control information (DCI).

[0273] In some example embodiments, the message may include the MAC CE for indicating an activation or deactivation of a semi-persistent reference signal for the at least one candidate cell.

[0274] In some example embodiments, the message may include at least one of: a time type of the at least one reference signal, the time type being periodic, aperiodic or semi-persistent, an identifier of a resource set comprising the at least one reference signal, the resource set being configured for a cell switch, an identifier of a resource set associated with layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) CSI acquisition, an identifier of a report configuration associated with the LTM CSI acquisition, at least one identifier of the at least one reference signal, or information of the at least one candidate cell.

[0275] In some example embodiments, a reserved bit in the message may indicate that the results of the at least one measurement is not reported to the first cell.

[0276] In some example embodiments, the first apparatus 110 may, in response to receiving the message or transmitting an acknowledgement of the message, perform the at least one measurement without transmitting the result to the first cell.

[0277] In some example embodiments, the message may be received before a cell switch, and the first apparatus 110 may, in response to the cell switch to a target candidate cell being performed, transmit the result of the at least one measurement to at least one of: the target candidate cell, or a candidate cell associated with the at least one reference signal for the at least one measurement.

[0278] In some example embodiments, the message may include a cell switch command indicating a cell switch to a target candidate cell, the at least one reference signal being associated with at least one of: the target candidate cell or transmission configuration indication (TCI) state in the cell switch command for handover, and the first apparatus is caused to: performing the at least one measurement based on the at least one reference signal.

[0279] In some example embodiments, the first apparatus 110 may perform the at least one measurement based on spatial domain information obtained from the TCI state.

[0280] In some example embodiments, the result of the at least one measurement may include at least one of the following report quantities: a channel quality indicator (CQI), a precodingmatrix indicator (PMI), a channel state information reference signal (CSI-RS) resource indicator (CRI), a synchronization signal and physical broadcast channel (SS / PBCH) block resource indicator (SSBRI), a layer indicator (LI), or a rank indicator (RI).

[0281] In some example embodiments, the first apparatus 110 may receive, from the second apparatus, a message for an activation of a candidate transmission configuration indication (TCI) state; and stop a measurement on the at least one reference signal for CSI for at least one candidate cell without an activated TCI.

[0282] In some example embodiments, the first apparatus 110 may perform at least one physical random access channel (PRACH) transmission for an early uplink synchronization; and stop a measurement on the at least one reference signal for CSI for at least one candidate cell without being performed the early uplink synchronization.

[0283] In some example embodiments, the first apparatus 110 may transmit, to the second apparatus, at least one of: a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of: thing maximum number of cells or reference signals for which the at least one measurement is performed, or thing maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

[0284] FIG. 14 shows a flowchart of an example method 1400 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 1400 will be described from the perspective of the second apparatus 120 in FIG. 7.

[0285] At block 1410, the second apparatus 120 transmits, to a first apparatus, a configuration of a set of reference signals for measurements of at least one candidate cell for a cell switch or mobility.

[0286] At block 1420, the second apparatus 120 transmits, to the first apparatus, a message indicating at least one reference signal of the set of reference signals, the message further indicating to perform at least one measurement on the at least one reference signal for channel state information (CSI) of the at least one candidate cell without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the firstapparatus or a cell providing the message.

[0287] In some example embodiments, the message may include at least one of: a medium access control control element (MAC CE), or downlink control information (DCI).

[0288] In some example embodiments, the message may include the MAC CE for indicating an activation or deactivation of a semi-persistent reference signal for the at least one candidate cell.

[0289] In some example embodiments, the message may include at least one of: a time type of the at least one reference signal, the time type being periodic, aperiodic or semi-persistent, an identifier of a resource set comprising the at least one reference signal, the resource set being configured for a cell switch, an identifier of a resource set associated with layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) CSI acquisition, an identifier of a report configuration associated with the LTM CSI acquisition, at least one identifier of the at least one reference signal, or information of the at least one candidate cell.

[0290] In some example embodiments, a reserved bit in the message may indicate that the results of the at least one measurement is not reported to the first cell.

[0291] In some example embodiments, the message may be transmitted before transmitting a cell switch command to the first apparatus.

[0292] In some example embodiments, the message may include a cell switch command indicating a cell switch to a target candidate cell, the at least one reference signal being associated with at least one of: the target candidate cell or transmission configuration indication (TCI) state in the cell switch command for handover.

[0293] In some example embodiments, the second apparatus 120 may transmit, to the target candidate cell, a notification of the cell switch, the notification indicating information of the at least one reference signal.

[0294] In some example embodiments, the target candidate cell may be associated with the second apparatus, and the second apparatus 120 may, in response to receiving the notification, activate or start transmitting the at least one reference signal via the target candidate cell.

[0295] In some example embodiments, the second apparatus 120 may include a centralized unit, a first distributed unit controlling the serving cell before the cell switch, and a second distributed unit controlling the target candidate cell, and wherein the notification is transmittedfrom the first distributed unit to the second distributed unit via the centralized unit.

[0296] In some example embodiments, the target candidate cell may be associated with a third apparatus, the second apparatus 120 may include a first distributed unit controlling the serving cell before the cell switch and a first centralized unit controlling the first distributed unit, and the third apparatus may include a second distributed unit controlling the target candidate cell and a second centralized unit controlling the second distributed unit, and wherein the notification is transmitted from the first distributed unit to the first centralized unit, then to the second distributed unit via the second centralized unit.

[0297] In some example embodiments, the second apparatus 120 may receive, from the first apparatus, at least one of: a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of: thing maximum number of cells or reference signals for which the at least one measurement is performed, or thing maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

[0298] In some example embodiments, a first apparatus capable of performing any of the method 900 (for example, the first apparatus 110 in FIG. 3) may comprise means for performing the respective operations of the method 900. 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 110 may be implemented as or included in the first apparatus 110 in FIG. 3.

[0299] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, a configuration regarding a channel state information (CSI) reporting, the configuration comprising at least one reference signal for at least one measurement for CSI of at least one candidate cell for a cell switch or mobility, wherein the configuration indicates the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration; and means for performing, based on the configuration, the at least one measurement based on the at least one reference signal without reporting the result of the at least one measurement to the first cell.

[0300] In some example embodiments, the configuration comprises at least one of: aconfiguration of the first cell, or a layer 1 / layer 2 (L1 / L2) triggered mobility (LTM)-based configuration.

[0301] In some example embodiments, the configuration is associated with layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) based on at least one of an LTM reporting configuration identifier, or an LTM resource configuration for the at least one measurement.

[0302] In some example embodiments, the result of the at least one measurement comprises at least one of the following report quantities: a channel quality indicator (CQI), a precoding matrix indicator (PMI), a channel state information reference signal (CSLRS) resource indicator (CRI), a synchronization signal and physical broadcast channel (SS / PBCH) block resource indicator (SSBRI), a layer indicator (LI), or a rank indicator (RI).

[0303] In some example embodiments, the configuration indicates which report quantity is included in the result of the at least one measurement.

[0304] In some example embodiments, the first apparatus further comprises: means for in response to a cell switch to a target candidate cell being performed, transmitting the result of the at least one measurement to at least one of: the target candidate cell, or a candidate cell associated with the at least one reference signal for the at least one measurement.

[0305] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, a command for a cell switch to a target candidate cell, the command indicating the target candidate cell and a transmission configuration indication (TCI) state associated with the target candidate cell; and means for performing a measurement associated with at least one of: the target candidate cell, or the TCI state.

[0306] In some example embodiments, the first apparatus further comprises: means for in response to receiving the command, stopping at least one of: a measurement on a candidate cell different from the target candidate cell, or a measurement on a reference signal not associated with the TCI state.

[0307] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, a message for an activation of a candidate transmission configuration indication (TCI) state; and means for stopping a measurement on the at least one reference signal for CSI for at least one candidate cell without an activated TCI.

[0308] In some example embodiments, the first apparatus further comprises: means forperforming at least one physical random access channel (PRACH) transmission for an early uplink synchronization; and means for stopping a measurement on the at least one reference signal for CSI for at least one candidate cell without being performed the early uplink synchronization.

[0309] In some example embodiments, the configuration comprises an indication with a first value, the indication with the first value indicating the at least one measurement without reporting a result of the at least one measurement to the first cell.

[0310] In some example embodiments, the configuration comprises a report quantity field with a quantity value, the report quantity field with the quantity value indicating the at least one measurement without reporting the result of the at least one measurement to the first cell, wherein the quantity value comprises at least one of: a channel quality indicator (CQI), a precoding matrix indicator (PMI), a layer indicator (LI), a rank indicator (RI), or a further value other than a reference signal received power (RSRP) field or signal to interference plus noise ratio (SINR) field.

[0311] In some example embodiments, the type of CSI reporting comprises at least one of: a periodic CSI reporting, an aperiodic CSI reporting, a semi-persistent CSI reporting, or an event- triggered CSI reporting.

[0312] In some example embodiments, the CSI reporting comprises a periodic or semi- persistent report on physical uplink control channel (PUCCH), and an absence of configuration information indicative of uplink resources for reporting at least one measurement result indicates the at least one measurement without reporting a result of the at least one measurement to the first cell.

[0313] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, at least one of: means for a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or means for a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of: means for thing maximum number of cells or reference signals for which the at least one measurement is performed, or means for thing maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

[0314] In some example embodiments, the first apparatus comprises a terminal device and the second apparatus comprises a network device.

[0315] In some example embodiments, a second apparatus capable of performing any of the method 1000 (for example, the second apparatus 120 in FIG. 3) may comprise means for performing the respective operations of the method 1000. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second apparatus 120 in FIG. 3.

[0316] In some example embodiments, the second apparatus comprises means for transmitting, to a first apparatus, a configuration regarding a channel state information (CSI) reporting, the configuration comprising at least one reference signal for at least one measurement for CSI of at least one candidate cell for a cell switch or mobility, wherein the configuration indicates the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the configuration.

[0317] In some example embodiments, the second apparatus further comprises: means for receiving, from the first apparatus, at least one of means for a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or means for a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of means for thing maximum number of cells or reference signals for which the at least one measurement is performed, or means for thing maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

[0318] In some example embodiments, the configuration comprises an indication with a first value, the indication with the first value indicating the at least one measurement without reporting a result of the at least one measurement to the first cell.

[0319] In some example embodiments, the configuration comprises a report quantity field with a quantity value, the report quantity field with the quantity value indicating the at least one measurement without reporting a result of the at least one measurement to the first cell, wherein the quantity value comprises at least one of a channel quality indicator (CQI), a precodingmatrix indicator (PMI), a layer indicator (LI), a rank indicator (RI), or a further field other than a reference signal received power (RSRP) field or signal to interference plus noise ratio (SINR) field.

[0320] In some example embodiments, the CSI reporting comprises at least one of: a periodic CSI reporting, an aperiodic CSI reporting, a semi-persistent CSI reporting, or an event-triggered CSI reporting.

[0321] In some example embodiments, the CSI reporting comprises a periodic or semi- persistent report on physical uplink control channel (PUCCH), and an absence of configuration information indicative of uplink resources for reporting at least one measurement indicates the at least one measurement without reporting a result of the at least one measurement to the first cell.

[0322] In some example embodiments, the configuration comprises a radio resource control configuration.

[0323] In some example embodiments, a first apparatus capable of performing any of the method 1100 (for example, the first apparatus 110 in FIG. 6) may comprise means for performing the respective operations of the method 1100. 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 110 in FIG. 6.

[0324] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; means for receiving, from the second apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration; and means for performing, based on the message, the at least one measurement based on the at least one reference signal without reporting the result of the measurement to the first cell.

[0325] In some example embodiments, a reserved bit in the message indicates the at least one measurement without reporting the result to the first cell.

[0326] In some example embodiments, the CSI reporting comprises a semi-persistent (SP)CSI report via physical uplink control channel (PUCCH), and the message comprises a medium access control control element (MAC CE) triggering the SP CSI report.

[0327] In some example embodiments, a logical channel identifier (LCID) in an MAC subheader of the MAC CE indicates that the first apparatus is configured not to report the result to the first cell.

[0328] In some example embodiments, the CSI reporting comprises at least one of an aperiodic (AP) CSI report via physical uplink shared channel (PUSCH) or a semi-persistent (SP) CSI report via PUSCH, and the message comprises downlink control information (DCI) triggering the at least one of AP CSI report or SP CSI report.

[0329] In some example embodiments, an absence of information indicative of uplink resources in the DCI for reporting at least one measurement indicates that the result is not reported to the first cell.

[0330] In some example embodiments, the configuration is associated with layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) based on at least one of an LTM reporting configuration identifier, or an LTM resource configuration for the at least one measurement.

[0331] In some example embodiments, the result of the at least one measurement comprises at least one of the following report quantities: a channel quality indicator (CQI), a precoding matrix indicator (PMI), a channel state information reference signal (CSLRS) resource indicator (CRI), a synchronization signal and physical broadcast channel (SS / PBCH) block resource indicator (SSBRI), a layer indicator (LI), or a rank indicator (RI).

[0332] In some example embodiments, the first apparatus further comprises: means for in response to a cell switch to a target candidate cell being performed, transmitting the result of the at least one measurement to at least one of: the target candidate cell, or a candidate cell associated with the at least one reference signal for the at least one measurement.

[0333] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, a command for a cell switch to a target candidate cell, the command indicating the target candidate cell and a transmission configuration indication (TCI) state associated with the target candidate cell; and means for performing a measurement associated with at least one of: the target candidate cell, or the TCI state.

[0334] In some example embodiments, the first apparatus further comprises: means for inresponse to receiving the command, stopping at least one of: a measurement on a candidate cell different from the target candidate cell, or a measurement on a reference signal not associated with the TCI state.

[0335] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, a message for an activation of a candidate transmission configuration indication (TCI) state; and means for stopping a measurement on the at least one reference signal for CSI for at least one candidate cell without an activated TCI.

[0336] In some example embodiments, the first apparatus further comprises: means for performing at least one physical random access channel (PRACH) transmission for an early uplink synchronization; and means for stopping a measurement on the at least one reference signal for CSI for at least one candidate cell without being performed the early uplink synchronization.

[0337] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, at least one of: means for a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or means for a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of: means for thing maximum number of cells or reference signals for which the at least one measurement is performed, or means for thing maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

[0338] In some example embodiments, a second apparatus capable of performing any of the method 1200 (for example, the second apparatus 120 in FIG. 6) may comprise means for performing the respective operations of the method 1200. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second apparatus 120 in FIG. 6.

[0339] In some example embodiments, the second apparatus comprises means for transmitting, to a first apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; and means for transmitting, to the first apparatus, a message for triggering the CSIreporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration.

[0340] In some example embodiments, a reserved bit in the message indicates the at least one measurement without reporting the result to the first cell.

[0341] In some example embodiments, the CSI reporting comprises a semi-persistent (SP) CSI report via physical uplink control channel (PUCCH), and the message comprises a medium access control control element (MAC CE) triggering the SP CSI report.

[0342] In some example embodiments, a logical channel identifier (LCID) in an MAC subheader of the MAC CE indicates that the first apparatus is configured not to report the result to the first cell.

[0343] In some example embodiments, the CSI reporting comprises at least one of: an aperiodic (AP) CSI report via physical uplink shared channel (PUSCH) or a semi-persistent (SP) CSI report via PUSCH, and the message comprises downlink control information (DCI) triggering the at least one of: AP CSI report or SP CSI report.

[0344] In some example embodiments, an absence of information indicative of uplink resources in the DCI for reporting at least one measurement indicates that the result is not reported to the first cell.

[0345] In some example embodiments, the second apparatus further comprises: means for receiving, from the first apparatus, at least one of: means for a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or means for a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of: means for thing maximum number of cells or reference signals for which the at least one measurement is performed, or means for thing maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

[0346] In some example embodiments, a first apparatus capable of performing any of the method 1300 (for example, the first apparatus 110 in FIG. 7) may comprise means for performing the respective operations of the method 1300. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or softwaremodule. The first apparatus may be implemented as or included in the first apparatus 110 in FIG. 7.

[0347] In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, a configuration of a set of reference signals for measurements of at least one candidate cell for a cell switch or mobility; means for receiving, from the second apparatus, a message indicating at least one reference signal of the set of reference signals, the message further indicating to perform at least one measurement on the at least one reference signal for channel state information (CSI) of the at least one candidate cell without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the message; and means for performing, based on the message, the at least one measurement without transmitting the result to the first cell.

[0348] In some example embodiments, the message comprises at least one of a medium access control control element (MAC CE), or downlink control information (DCI).

[0349] In some example embodiments, the message comprises the MAC CE for indicating an activation or deactivation of a semi-persistent reference signal for the at least one candidate cell.

[0350] In some example embodiments, the message comprises at least one of a time type of the at least one reference signal, the time type being periodic, aperiodic or semi-persistent, an identifier of a resource set comprising the at least one reference signal, the resource set being configured for a cell switch, an identifier of a resource set associated with layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) CSI acquisition, an identifier of a report configuration associated with the LTM CSI acquisition, at least one identifier of the at least one reference signal, or information of the at least one candidate cell.

[0351] In some example embodiments, a reserved bit in the message indicates that the results of the at least one measurement is not reported to the first cell.

[0352] In some example embodiments, the first apparatus further comprises: means for in response to receiving the message or transmitting an acknowledgement of the message, performing the at least one measurement without transmitting the result to the first cell.

[0353] In some example embodiments, the message is received before a cell switch, and the first apparatus is further caused to: means for in response to the cell switch to a target candidate cell being performed, transmitting the result of the at least one measurement to at least one of:the target candidate cell, or a candidate cell associated with the at least one reference signal for the at least one measurement.

[0354] In some example embodiments, the message comprises a cell switch command indicating a cell switch to a target candidate cell, the at least one reference signal being associated with at least one of: the target candidate cell or transmission configuration indication (TCI) state in the cell switch command for handover, and the first apparatus is caused to: means for performing the at least one measurement based on the at least one reference signal.

[0355] In some example embodiments, the first apparatus further comprises: means for performing the at least one measurement based on spatial domain information obtained from the TCI state.

[0356] In some example embodiments, the result of the at least one measurement comprises at least one of the following report quantities: a channel quality indicator (CQI), a precoding matrix indicator (PMI), a channel state information reference signal (CSI-RS) resource indicator (CRI), a synchronization signal and physical broadcast channel (SS / PBCH) block resource indicator (SSBRI), a layer indicator (LI), or a rank indicator (RI).

[0357] In some example embodiments, the first apparatus further comprises: means for receiving, from the second apparatus, a message for an activation of a candidate transmission configuration indication (TCI) state; and means for stopping a measurement on the at least one reference signal for CSI for at least one candidate cell without an activated TCI.

[0358] In some example embodiments, the first apparatus further comprises: means for performing at least one physical random access channel (PRACH) transmission for an early uplink synchronization; and means for stopping a measurement on the at least one reference signal for CSI for at least one candidate cell without being performed the early uplink synchronization.

[0359] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, at least one of: means for a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or means for a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of: means for thing maximum number of cells or reference signals for which the at least one measurement is performed, ormeans for thing maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

[0360] In some example embodiments, a second apparatus capable of performing any of the method 1400 (for example, the second apparatus 120 in FIG. 7) may comprise means for performing the respective operations of the method 1400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second apparatus 120 in FIG. 7.

[0361] In some example embodiments, the second apparatus comprises means for transmitting, to a first apparatus, a configuration of a set of reference signals for measurements of at least one candidate cell for a cell switch or mobility; and means for transmitting, to the first apparatus, a message indicating at least one reference signal of the set of reference signals, the message further indicating to perform at least one measurement on the at least one reference signal for channel state information (CSI) of the at least one candidate cell without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the message.

[0362] In some example embodiments, the message comprises at least one of: a medium access control control element (MAC CE), or downlink control information (DCI).

[0363] In some example embodiments, the message comprises the MAC CE for indicating an activation or deactivation of a semi-persistent reference signal for the at least one candidate cell.

[0364] In some example embodiments, the message comprises at least one of: a time type of the at least one reference signal, the time type being periodic, aperiodic or semi-persistent, an identifier of a resource set comprising the at least one reference signal, the resource set being configured for a cell switch, an identifier of a resource set associated with layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) CSI acquisition, an identifier of a report configuration associated with the LTM CSI acquisition, at least one identifier of the at least one reference signal, or information of the at least one candidate cell.

[0365] In some example embodiments, a reserved bit in the message indicates that the results of the at least one measurement is not reported to the first cell.

[0366] In some example embodiments, the message is transmitted before transmitting a cell switch command to the first apparatus.

[0367] In some example embodiments, the message comprises a cell switch command indicating a cell switch to a target candidate cell, the at least one reference signal being associated with at least one of: the target candidate cell or transmission configuration indication (TCI) state in the cell switch command for handover.

[0368] In some example embodiments, the second apparatus further comprises: means for transmitting, to the target candidate cell, a notification of the cell switch, the notification indicating information of the at least one reference signal.

[0369] In some example embodiments, the target candidate cell is associated with the second apparatus, and the second apparatus further comprises: means for in response to receiving the notification, activating or start transmitting the at least one reference signal via the target candidate cell.

[0370] In some example embodiments, the second apparatus comprises a centralized unit, a first distributed unit controlling the serving cell before the cell switch, and a second distributed unit controlling the target candidate cell, and wherein the notification is transmitted from the first distributed unit to the second distributed unit via the centralized unit.

[0371] In some example embodiments, the target candidate cell is associated with a third apparatus, the second apparatus comprises a first distributed unit controlling the serving cell before the cell switch and a first centralized unit controlling the first distributed unit, and the third apparatus comprises a second distributed unit controlling the target candidate cell and a second centralized unit controlling the second distributed unit, and wherein the notification is transmitted from the first distributed unit to the first centralized unit, then to the second distributed unit via the second centralized unit.

[0372] In some example embodiments, the second apparatus is further caused to: means for receiving, from the first apparatus, at least one of: means for a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or means for a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of: means for thing maximum number of cells or reference signals for which the at least one measurement is performed, or means for thing maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

[0373] FIG. 15 is a simplified block diagram of a device 1500 that is suitable for implementing example embodiments of the present disclosure. The device 1500 may be provided to implement a communication device, for example, the first apparatus 110 or the second apparatus 120 as shown in FIGS. 3, 6, and 7. As shown, the device 1500 includes one or more processors 1510, one or more memories 1520 coupled to the processor 1510, and one or more communication modules 1540 coupled to the processor 1510.

[0374] The communication module 1540 is for bidirectional communications. The communication module 1540 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 1540 may include at least one antenna.

[0375] The processor 1510 may be of any type suitable to the local technical network and may 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 1500 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.

[0376] The memory 1520 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) 1524, 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) 1522 and other volatile memories that will not last in the power-down duration.

[0377] A computer program 1530 includes computer executable instructions that are executed by the associated processor 1510. The instructions of the program 1530 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 1530 may be stored in the memory, e.g., the ROM 1524. The processor 1510 may perform any suitable actions and processing by loading the program 1530 into the RAM 1522.

[0378] The example embodiments of the present disclosure may be implemented by means ofthe program 1530 so that the device 1500 may perform any process of the disclosure as discussed with reference to FIG. 2 to 8. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0379] In some example embodiments, the program 1530 may be tangibly contained in a computer readable medium which may be included in the device 1500 (such as in the memory 1520) or other storage devices that are accessible by the device 1500. The device 1500 may load the program 1530 from the computer readable medium to the RAM 1522 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 storage persistency (e.g., RAM vs. ROM).

[0380] FIG. 16 shows an example of the computer readable medium 1600 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 1600 has the program 1530 stored thereon.

[0381] 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.

[0382] 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 datatypes. 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.

[0383] 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 in the 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.

[0384] 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.

[0385] 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 readonly 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.

[0386] 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.

[0387] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure 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

WHAT IS CLAIMED IS:

1. A first apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to: receive, from a second apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; receive, from the second apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration; and perform, based on the message, the at least one measurement based on the at least one reference signal without reporting the result of the measurement to the first cell.

2. The first apparatus of claim 1, wherein a reserved bit in the message indicates the at least one measurement without reporting the result to the first cell.

3. The first apparatus of claim 1 or 2, wherein the CSI reporting comprises a semi- persistent (SP) CSI report via physical uplink control channel (PUCCH), and the message comprises a medium access control control element (MAC CE) triggering the SP CSI report.

4. The first apparatus of claim 3, wherein a logical channel identifier (LCID) in an MAC sub-header of the MAC CE indicates that the first apparatus is configured not to report the result to the first cell.

5. The first apparatus of claim 1, wherein the CSI reporting comprises at least one of: an aperiodic (AP) CSI report via physical uplink shared channel (PUSCH) or a semi-persistent (SP) CSI report via PUSCH, and the message comprises downlink control information (DCI) triggering the at least one of: AP CSI report or SP CSI report.

736. The first apparatus of claim 5, wherein an absence of information indicative of uplink resources in the DCI for reporting at least one measurement indicates that the result is not reported to the first cell.

7. The first apparatus of any of claims 1-6, wherein the configuration is associated with layer 1 / layer 2 (L1 / L2) triggered mobility (LTM) based on at least one of an LTM reporting configuration identifier, or an LTM resource configuration for the at least one measurement.

8. The first apparatus of any of claims 1-7, wherein the result of the at least one measurement comprises at least one of the following report quantities: a channel quality indicator (CQI), a precoding matrix indicator (PMI), a channel state information reference signal (CSLRS) resource indicator (CRI), a synchronization signal and physical broadcast channel (SS / PBCH) block resource indicator (SSBRI), a layer indicator (LI), or a rank indicator (RI).

9. The first apparatus of any of claims 1-8, wherein the first apparatus is further caused to: in response to a cell switch to a target candidate cell being performed, transmit the result of the at least one measurement to at least one of: the target candidate cell, or a candidate cell associated with the at least one reference signal for the at least one measurement.

10. The first apparatus of any of claims 1-9, wherein the first apparatus is further caused to: receive, from the second apparatus, a command for a cell switch to a target candidate cell, the command indicating the target candidate cell and a transmission configuration indication (TCI) state associated with the target candidate cell; and perform a measurement associated with at least one of: the target candidate cell, or the TCI state.

11. The first apparatus of claim 10, wherein the first apparatus is further caused to: in response to receiving the command, stop at least one of: a measurement on a candidate cell different from the target candidate cell, or a measurement on a reference signal not associated with the TCI state.7412. The first apparatus of any of claims 1-11, wherein the first apparatus is further caused to: receive, from the second apparatus, a message for an activation of a candidate transmission configuration indication (TCI) state; and stop a measurement on the at least one reference signal for CSI for at least one candidate cell without an activated TCI.

13. The first apparatus of any of claims 1-12, wherein the first apparatus is further caused to: perform at least one physical random access channel (PRACH) transmission for an early uplink synchronization; and stop a measurement on the at least one reference signal for CSI for at least one candidate cell without being performed the early uplink synchronization.

14. The first apparatus of any of claims 1-13, wherein the first apparatus is further caused to: transmit, to the second apparatus, at least one of: a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of: the maximum number of cells or reference signals for which the at least one measurement is performed, or the maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

15. The first apparatus of any of claims 1-14, wherein the first apparatus comprises a terminal device, and the second apparatus comprises a network device.

16. A second apparatus comprising: at least one processor; and75at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to: transmit, to a first apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; and transmit, to the first apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the configuration.

17. The second apparatus of claim 16, wherein a reserved bit in the message indicates the at least one measurement without reporting the result to the first cell.

18. The second apparatus of claim 16 or 17, wherein the CSI reporting comprises a semi- persistent (SP) CSI report via physical uplink control channel (PUCCH), and the message comprises a medium access control control element (MAC CE) triggering the SP CSI report.

19. The second apparatus of claim 18, wherein a logical channel identifier (LCID) in an MAC sub-header of the MAC CE indicates that the first apparatus is configured not to report the result to the first cell.

20. The second apparatus of claim 16, wherein the CSI reporting comprises at least one of an aperiodic (AP) CSI report via physical uplink shared channel (PUSCH) or a semi- persistent (SP) CSI report via PUSCH, and the message comprises downlink control information (DCI) triggering the at least one of AP CSI report or SP CSI report.

21. The second apparatus of claim 20, wherein an absence of information indicative of uplink resources in the DCI for reporting at least one measurement indicates that the result is not reported to the first cell.

22. The second apparatus of any of claims 16-21, wherein the second apparatus is further caused to: receive, from the first apparatus, at least one of:a first capability for supporting the at least one measurement without reporting the result to the first cell before a cell switch to a target candidate cell, or a second capability for supporting the at least one measurement without reporting the result to the first cell during or after the cell switch, wherein the first capability or the second capability comprises at least one of the maximum number of cells or reference signals for which the at least one measurement is performed, or the maximum number of cells or reference signals for which the at least one measurement is performed within a time duration.

23. A method comprising: receiving, at a first apparatus from a second apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; receiving, from the second apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the configuration; and performing, based on the message, the at least one measurement based on the at least one reference signal without reporting the result of the measurement to the first cell.

24. A method comprising: transmitting, at a second apparatus to a first apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; and transmitting, to the first apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration.

25. A first apparatus comprising: means for receiving, from a second apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; means for receiving, from the second apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of a serving cell of the first apparatus or a cell providing the configuration; and means for performing, based on the message, the at least one measurement based on the at least one reference signal without reporting the result of the measurement to the first cell.

26. A second apparatus comprising: means for transmitting, to a first apparatus, a configuration of at least one reference signal for at least one measurement for channel state information (CSI) reporting of at least one candidate cell for a cell switch or mobility; and means for transmitting, to the first apparatus, a message for triggering the CSI reporting, the message indicating the at least one measurement without reporting a result of the at least one measurement to a first cell, the first cell comprising at least one of: a serving cell of the first apparatus or a cell providing the configuration.

27. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 23 or 24.

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