Secondary cell activation based on aperiodic reference signals - Patents.com

Abstract

The present disclosure relates to a device, a method, an apparatus, and a computer-readable storage medium for a secondary cell (SCell) activation based on an aperiodic reference signal (ARS). The method includes transmitting a request from a first device to a second device to trigger transmission of the aperiodic reference signal based on beam information available at the time of secondary cell activation, and receiving the aperiodic reference signal for the secondary cell activation.

Description

[Technical Field]

[0001] Embodiments of the present disclosure relate generally to the field of telecommunications, and more particularly to a device, method, apparatus, and computer-readable storage medium for Aperiodic Reference Signal (ARS) based Secondary Cell (SCell) activation. [Background technology]

[0002] As in Long Term Evolution (LTE), in New Radio (NR), SCells can be activated or deactivated by the network to enable reasonable UE battery consumption when carrier aggregation (CA) is configured. When activating an SCell, it takes time to transition from a deactivated state to an activated state. In a fifth-generation mobile communication technology (5G) New Radio (NR) system, research on how to reduce the activation delay requirements on both the network side and the user equipment (UE) side should be further discussed. Summary of the Invention

[0003] Generally, the example embodiments of the present disclosure provide a solution for ARS-based SCell activation.

[0004] In a first aspect, a method is provided, the method including: transmitting, from a first device to a second device, a request to trigger transmission of an aperiodic reference signal based on beam information available upon activation of a secondary cell; and receiving the aperiodic reference signal for activation of the secondary cell.

[0005] In a second aspect, a method is provided, the method including: receiving, in a second device, from a first device, a request to trigger transmission of an aperiodic reference signal generated by the first device based on beam information available at the time of activation of a secondary cell; and performing the triggered transmission of the aperiodic reference signal to the first device for the activation of the secondary cell.

[0006] In a third aspect, there is provided a first device comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the first device to perform at least a method according to the first aspect.

[0007] In a fourth aspect, there is provided a second device comprising at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the second device to perform at least a method according to the second aspect.

[0008] In a fifth aspect, an apparatus is provided that includes means for transmitting, to a second device, a request to trigger transmission of an aperiodic reference signal based on beam information available upon activation of a secondary cell, and means for receiving the aperiodic reference signal for activation of the secondary cell.

[0009] In a sixth aspect, an apparatus is provided that includes means for receiving, from a first device, a request to trigger transmission of an aperiodic reference signal generated by the first device based on beam information available at the time of activation of a secondary cell, and means for performing such that transmission of the aperiodic reference signal to the first device for activation of the secondary cell is triggered.

[0010] In a seventh aspect, there is provided a computer readable medium having stored thereon a computer program which, when executed by at least one processor of a device, causes the device to perform a method according to the first or second aspect.

[0011] Other features and advantages of the presently disclosed embodiments will become apparent from the following description of specific embodiments, taken in conjunction with the accompanying drawings which illustrate, by way of example, the principles of the presently disclosed embodiments.

[0012] Embodiments of the present disclosure are presented by way of example, and their advantages will be explained in more detail below with reference to the accompanying drawings. Throughout the drawings, the same or similar reference numbers may refer to the same or similar elements. [Brief explanation of the drawings]

[0013] [Figure 1] 1 illustrates an exemplary environment in which exemplary embodiments of the present disclosure may be implemented. [Figure 2] 10 shows a signaling chart illustrating a process of ARS-based SCell activation, according to some example embodiments of the present disclosure. [Figure 3A] 10 illustrates an example of a UE requesting ARS for activation of an SCell, according to some example embodiments of the present disclosure. [Figure 3B] 10 illustrates an example of a UE requesting ARS for activation of an SCell, according to some example embodiments of the present disclosure. [Figure 3C] 10 illustrates an example of a UE requesting ARS for activation of an SCell, according to some example embodiments of the present disclosure. [Figure 4] 1 illustrates a flowchart of an example method for ARS-based SCell activation, according to some example embodiments of the present disclosure. [Figure 5] 1 illustrates a flowchart of an example method for ARS-based SCell activation, according to some example embodiments of the present disclosure. [Figure 6]FIG. 1 shows a simplified block diagram of a device suitable for implementing exemplary embodiments of the present disclosure. [Figure 7] 1 illustrates a block diagram of an exemplary computer-readable medium according to some embodiments of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0014] The principles of the present disclosure will now be described with reference to some exemplary embodiments. It should be understood that these embodiments are provided for illustrative purposes only, to assist those skilled in the art in understanding and practicing the present disclosure, but do not imply any limitation on the scope of the present disclosure. The embodiments described herein can be implemented in various ways other than those described below.

[0015] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0016] References in this disclosure to "one embodiment," "embodiment," "exemplary embodiment," etc. indicate that the described embodiment may include a particular feature, structure, or characteristic, but not all embodiments need include the particular feature, structure, or characteristic. Moreover, such phrases do not necessarily refer to the same embodiment. Furthermore, it is submitted that when a particular feature, structure, or characteristic is described in connection with one embodiment, 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.

[0017] While the terms "first," "second," etc. may be used herein to describe various elements, it should be understood that these elements should not be limited by these terms. These terms are used only to distinguish one element from another. For example, a first element could be referred to as a second element, and similarly, a second element could be referred to as a first element, without departing from the scope of the exemplary embodiments. As used herein, the term "and / or" includes any and all combinations of one or more of the listed terms.

[0018] As used herein, "at least one of " and "at least one of " are similar phrases, and when a list of two or more elements is joined by "and" or "or", mean at least one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0019] As used herein, unless explicitly stated, performing a step "in response to A" does not indicate that the step is performed immediately after "A" occurs, but may include one or more intervening steps.

[0020] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit example embodiments. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms unless the context clearly dictates otherwise. Furthermore, it will be 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 exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0021] As used in this application, the term "circuit" may refer to one or more or all of the following: (a) Hardware-only circuit implementation (e.g., implementation using only analog and / or digital circuits) (b) A combination of hardware circuitry and software (where applicable). (i) a combination of analog and / or digital hardware circuitry and software / firmware; (ii) Any portion of a hardware processor (including a digital signal processor) with software, software, and memory that cooperates to cause a device, such as a mobile phone or server, to perform various functions. (c) A hardware circuit and / or processor, such as a microprocessor or portion of a microprocessor, that requires software (e.g., firmware) for operation, and when not required for operation, the software may not be present.

[0022] This definition of circuit applies to all uses of the term in this application, including any claims. As a further example, the term circuit, as used in this application, also encompasses simply a hardware circuit or processor (or processors), or a portion of a hardware circuit or processor, as well as its (or their) accompanying software and / or firmware implementations. The term circuit also encompasses, for example, a baseband or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or network device, if applicable to certain claim elements.

[0023] As used herein, the term "communication network" refers to a network conforming to any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High Speed ​​Packet Access (HSPA), or Narrowband Internet of Things (NB-IoT). Furthermore, communications between terminal devices and network devices in a communication network may be performed according to any suitable generation of communication protocols, including, but not limited to, first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, fifth-generation (5G) communication protocols, and / or any other protocols currently known or developed in the future. Embodiments of the present disclosure may be applied to various communication systems. Given the rapid development of communications, there will naturally be future types of communication technologies and systems in which the present disclosure can be embodied. This should not be understood as limiting the scope of the present disclosure to only the aforementioned systems.

[0024] As used herein, the term "network device" refers to a node in a communication network through which a terminal device accesses the network and receives services therefrom. A network device may be referred to, depending on the terminology and technology applied, as a base station (BS) or access point (AP), e.g., a Node B (NodeB or NB), an evolved Node B (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 or pico node, a non-terrestrial network (NTN) or a non-terrestrial network device such as a satellite network device, a low Earth orbit (LEO) satellite, and a geosynchronous Earth orbit (GEO) satellite, an airborne network device, etc. In some exemplary embodiments, a radio access network (RAN) split architecture includes a centralized unit (CU) and a distributed unit (DU) in an IAB donor node. An IAB node includes a mobile terminal (IAB-MT) portion that behaves like a UE towards a parent node, and a DU portion of the IAB node that behaves like a base station towards a next-hop IAB node.

[0025] The term "terminal device" refers to any end device that may be capable of wireless communication. By way of example and not limitation, a terminal device may also be referred to as a communication device, user equipment (UE), subscriber station (SS), portable subscriber station, mobile station (MS), or access terminal (AT). Terminal devices may include, but are not limited to, mobile phones, cellular phones, smartphones, voice-over-IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback equipment, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop embedded equipment (LEEs), laptop mounted equipment (LMEs), USB dongles, smart devices, wireless customer premises equipment (CPEs), Internet of Things (loT) devices, watches or other wearables, head-mounted displays (HMDs), vehicles, drones, medical devices and applications (e.g., remote surgery), industrial devices and applications (e.g., robots and / or other wireless devices operating in industrial and / or automated processing chain contexts), consumer electronics devices, devices operating on commercial and / or industrial wireless networks, etc. Terminal devices may also correspond to the mobile termination (MT) portion 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.

[0026] As used herein, the terms "resource," "transmission resource," "resource block," "physical resource block (PRB)," "uplink resource," or "downlink resource" may refer to any resource for performing communication between a terminal device and a network device, such as a resource in the time domain, a resource in the frequency domain, a resource in the spatial domain, a resource in the code domain, or any other resource that enables communication. Hereinafter, unless explicitly stated, resources in both the frequency domain and the time domain are used as examples of transmission resources to describe some exemplary embodiments of the present disclosure. It should be noted that the exemplary embodiments of the present disclosure are equally applicable to other resources in other domains.

[0027] 1 illustrates an exemplary communication network 100 in which embodiments of the present disclosure may be implemented. As illustrated in FIG. 1, the communication network 100 may include a terminal device 110. Hereinafter, the terminal device 110 may also be referred to as a UE 110 or a first device 110.

[0028] The communication network 100 may further include a network device 120. Hereinafter, the network device 120 may be referred to as a gNB 120 or a second device 120. The terminal device 110 can communicate with the network device 120.

[0029] 1 is given for illustrative purposes, without implying any limitation, and communication network 100 may include any suitable number of network devices and terminal devices.

[0030] In some demonstrative embodiments, the link from network device 120 to terminal device 110 may be referred to as the downlink (DL), and the link from terminal device 110 to network device 120 may be referred to as the uplink (UL). In the DL, network device 120 is the transmit (TX) device (or transmitter) and terminal device 110 is the receive (RX) device (or receiver). In the UL, terminal device 110 is the TX device (or transmitter) and network device 120 is the RX device (or receiver).

[0031] Communications in communication environment 100 may utilize any suitable wireless communication technology and may be implemented according to any suitable communication protocol, including, but not limited to, cellular communication protocols such as first generation (1G), second generation (2G), third generation (3G), fourth generation (4G), fifth generation (5G), sixth generation (6G), wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11, and / or any other protocol now known or developed in the future. Further, communications may include, but are 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 access (OFDM), discrete Fourier transform spread OFDM (DFT-s-OFDM), and / or any other technology now known or developed in the future.

[0032] As mentioned above, in NR, an SCell may be activated or deactivated by the network to allow reasonable UE battery consumption when CA is configured. For example, an SCell activation / deactivation may be triggered by a Medium Access Control-Control Element (MAC CE) to indicate whether an SCell with SCellIndex i should be activated or deactivated.

[0033] When activating an SCell, it takes time to transition from a deactivated state to an activated state. In some conditions, e.g., an unknown target SCell, the activation delay may be very long due to cell detection, Layer 1 Reference Signal Received Power (L1-RSRP) measurements, and Channel State Information (CSI) measurements.

[0034] To reduce the delay, a fast SCell activation scheme is proposed to speed up the SCell activation procedure. A tracking aperiodic Channel State Information-Reference Signal (CSI-RS), i.e., A-TRS, can be configured for the SCell to assist Automatic Gain Control (AGC) and time / frequency synchronization.

[0035] For example, to enable fast SCell activation when CA is configured, aperiodic CSI-RS for tracking fast SCell activation may be configured for the SCell to support AGC and time / frequency synchronization. The MAC CE is used to trigger activation of one or more SCells and to trigger aperiodic CSI-RS for tracking fast SCell activation for (a set of) deactivated SCells.

[0036] Based on the A-TRS, the UE may monitor the A-TRS instead of the synchronization signal block (SSB) for cell synchronization. The A-TRS may be configured with a very short periodicity so that it may occur before the SSB, thus reducing the SCell activation delay.

[0037] However, in some scenarios, A-TRS may only be triggered when the SCell is known or the SCell is unknown but shares the same beam information as the active serving cell in the same band, i.e., in a contiguous intra-band scenario.

[0038] In other words, A-TRS can only be triggered if the network has beam information for the SCell to be activated, and therefore does not currently apply to unknown SCells.

[0039] However, the UE experiences a much longer activation delay when activating an unknown SCell due to beam measurements etc.

[0040] Known / unknown SCells are defined depending on whether the UE has sent a valid measurement report for the SCell within a certain period of time, which may not fully reflect the UE's latest knowledge of the SCell. For example, the UE may be performing intra-frequency measurements on a deactivated SCell when it receives the SCell activation command.

[0041] Therefore, a mechanism for triggering aperiodic reference signals upon secondary cell activation in both known and unknown SCell scenarios needs to be discussed.

[0042] According to some example embodiments of the present disclosure, a solution for ARS-based SCell activation is provided. In this solution, a UE may transmit a request for transmission to trigger an aperiodic reference signal (ARS) upon SCell activation based on available beam information. Upon receiving the request, ARS transmission is triggered in the gNB for SCell activation. Hereinafter, the term "ARS" may also be referred to as A-TRS or aperiodic CSI-RS. This solution may also be applied to the case of activating a primary secondary SCell (PSCell) upon secondary cell group (SCG) activation.

[0043] Preferred embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0044] Reference is now made to Figure 2, which illustrates a signaling chart 200 for communication in accordance with some example embodiments of the present disclosure. As shown in Figure 2, the signaling chart 200 includes a UE 110 and a gNB 120. For purposes of explanation, reference is made to Figure 1 to describe the signaling chart 200.

[0045] As shown in FIG. 2, the gNB 120 may send an SCell activation command to the UE 110 to notify that the SCell activation procedure should be initiated from the UE 110 (202).

[0046] UE 110 may then generate 204 a request to trigger ARS from gNB 120. For example, UE 110 may generate the request to trigger ARS based on its capabilities and / or whether available beam information has been acquired at UE 110.

[0047] If UE 110 has the capability to support a request that triggers an ARS, the capability may be reported from UE 110 to gNB 120. It should be appreciated that UE 110 may report its capability to gNB 120 before UE 110 decides to send and / or generate the request.

[0048] To generate the request, UE 110 may determine whether one or more SCells to be potentially activated are known. For example, UE 110 may determine whether these one or more SCells have been detected and / or whether measurement results for one or more SCells have been obtained. That is, UE 110 may determine whether available beam information for SCell activation has been acquired.

[0049] In some demonstrative embodiments, if UE 110 obtains available beam information for an SCell at the time of SCell activation, e.g., by performing intra-frequency measurements on a deactivated SCell that is being activated, UE 110 may select the best DL beam and request ARS to be triggered (transmitted) on the selected DL beam. That is, UE 110 may generate a request to trigger ARS indicating that ARS is to be triggered on the selected DL beam.

[0050] It is also possible that UE 110 does not have available beam information of the SCell at the time of activation of the SCell, i.e., the SCell is unknown by UE 110, and UE 110 may perform corresponding measurements on the SCell.

[0051] When UE 110 does not have available beam information, this may refer to two different scenarios. In some exemplary embodiments, the SCell has been detected at the time of SCell activation, but the SSB index has not been obtained. In this situation, UE 110 may determine at least one preferred beam based on the SSB index. For example, UE 110 may read the SSB index, e.g., 8*Tr in the SCell, to determine one or more candidate DL beams as at least one preferred beam. UE 110 may then generate a request indicating ARS to be triggered on one or more candidate DL beams, which may be identified by, e.g., one or more SSB indexes.

[0052] In some other exemplary embodiments, the SCell is not detected at the time of SCell activation, in which case UE 110 may perform cell detection before requesting ARS.

[0053] In some other exemplary embodiments, one or more pieces of information may be included in the request to assist in ARS triggering. For example, the request may include candidate / preferred beams from which the ARS is expected to be transmitted, which may be indicated by different indices or identities (IDs). Optionally, the candidate / preferred beams may be indicated by SSB indices acquired by the UE. As another option, the candidate / preferred beams may be indicated by CSI-RS IDs, such as the scellActivationRS-Id or non-zero power (NZP) CSI-RS-ResourceSetId configured on the SCell to be activated. Furthermore, the UE 110 may also prioritize beams on which ARS resources or A-TRS are configured for fast SCell activation.

[0054] Alternatively, or optionally, the request may include the configuration of one or more aperiodic reference signals and / or the number of ARS bursts expected on the candidate / preferred beam. The number of bursts may depend on the latest measurements or cell status at the UE 110. For example, if a cell is detected at the time of SCell activation, the UE 110 may request a single ARS for SCell activation. Otherwise, if a cell is not detected, the UE may request two or more ARS bursts for SCell activation.

[0055] Alternatively, or optionally, the request may include the use of the ARS burst for SCell activation, which indicates which of the activation steps following the SCell activation command the requested ARS burst will be used for, including AGC, time and frequency tracking, L1-RSRP measurements, fine time tracking, and channel measurements. By way of example, the three digits "use" may be used to indicate whether the ARS burst will be used for cell detection including AGC and time and frequency (T / F) tracking, L1-RSRP measurements, and / or CSI-RS measurements, respectively.

[0056] Alternatively, or optionally, the request may also include the configuration of one or more ARSs.

[0057] For example, if the SCell is in a deactivated state and a request is received, the network activates / trigger the ARS on the beam corresponding to the received SSB or QCL'd to the received SSB.

[0058] Referring again to FIG. 2, UE 110 may send a request to gNB 120 to trigger ARS (206). In some exemplary embodiments, the request is sent from UE 110 after UE 110 receives an SCell activation command from gNB 120 or after UE 110 sends a HARQ ACK in response to the activation command. A predetermined period is defined within which the UE should be able to send the request after UE 110 receives an SCell activation command from gNB 120 or sends a HARQ ACK in response to the activation command. If the UE fails to send the request within the predetermined period, the SCell is assumed to be activated according to a legacy unknown SCell activation procedure. For example, "T ARS_req The predetermined period, which may be expressed as "T", is the period for reporting L1 RSRP measurements when the CSI reporting resource on the PCell or any active serving cell is used to transmit the request. L1-RSRP,reporting For example, the threshold period "T ARS_req_threshold " may be set to send the request.

[0059] In some exemplary embodiments, the request is sent from the UE 110 to the gNB 120 via a MAC CE, or RRC message, or by reusing CSI reporting resources in the primary cell or active serving cell.

[0060] After receiving the request, the gNB 120 can trigger transmission of the ARS. As shown in Figure 2, the ARS may be transmitted from the gNB 120 to the UE 110 (208). Alternatively, or optionally, the ARS may also be transmitted to the UE 110 from another gNB (not shown). For example, transmission of the ARS may be triggered based on one or more pieces of information indicated in the request.

[0061] For example, if at least one candidate / preferred beam is indicated in the request, gNB120 may trigger an ARS transmission on the indicated at least one candidate / preferred beam for the SCell activation procedure. If at least one candidate / preferred beam is indicated by an SSB index, gNB120 may activate / trigger an ARS on the beam that corresponds to the received SSB index or is a quasi-colocation (QCL) assigned to the received SSB.

[0062] As another option, if the request indicates the use of an ARS burst for activation of the SCell, the gNB120 may trigger an ARS transmission based on the use of the ARS burst.

[0063] Additionally, gNB 120 may also send an indication of a Transmission Configuration Indicator (TCI) status to UE 110. UE 110 may monitor DL ​​ARS transmission based on the TCI status.

[0064] Based on the received ARS, UE 110 may perform cell synchronization (e.g., AGC and time / frequency synchronization) based on the ARS 210. After UE 110 completes cell synchronization based on the ARS, UE 110 may measure semi-periodic (SP) CSI-RS or periodic CSI-RS and send a CSI report for the SCell 212.

[0065] Optionally, the SP-CSI-RS may be activated in the same MAC CE of the ARS / TCI activation to avoid additional MAC uncertainty time. As another option, if the UE 110 indicates that the ARS is also used for CSI measurement, the UE 110 may also skip the SP-CSI-RS measurement and send a CSI report based on the ARS.

[0066] Although the case where ARS transmission is triggered based on a UE request has been described, it should be understood that gNB 120 may transmit ARS on one or more beams, which may be applied with or without a UE request, for cases where the SCell is known and cases where the SCell is unknown. As an example, ARS may be transmitted by gNB 120 based on the last measurement report from UE 110. Thus, if the UE can assume that the gNB transmitted ARS on the last used associated DL SSB and the SSB quality is still good (e.g., no time limit), UE 110 may activate SCell activation based on the ARS instead of the SSB.

[0067] In the solution of the present disclosure, the UE can benefit from available beam information and ARS to speed up activation of unknown SCells. With available DL beam information, the UE can treat previously unknown SCells as known and request ARS to assist with AGC and time / frequency tracking, and / or other activation steps on the best beam. This may enable the network to transmit ARS to the UE on the reported DL beam, which may reduce the activation time of the UE SCell.

[0068] Meanwhile, it can save an additional beam (i.e., L1-RSRP) measurement procedure for activating an unknown SCell. ARS may help the UE perform frequency and time tracking on the SCell for a shorter period, i.e., the duration of a CSI-RS burst, which may further reduce the activation delay due to SSB-based time / frequency tracking.

[0069] Some examples for triggering ARS transmission upon activation of an SCell may now be described in further detail with reference to FIGS. 3A-3C.

[0070] 3A, at the beginning of the timeline (i.e., T0), UE 110 receives an SCell activation command to activate an unknown SCell. For example, there is no active serving cell or known SCell on the band. Because the SCell is unknown, gNB 120 has not received a valid L3 measurement report within a period of time and therefore does not know, for example, the latest DL beam information on which UE 110 may be scheduled, and therefore cannot send a TCI indication.

[0071] In the example shown in Figure 3A, intra-frequency or serving cell measurements for an activated SCell have been made by UE 110, and thus UE 110 may determine DL beam information associated with, for example, SSB index #1 upon activation of the SCell. ARS_req (i.e., the period 302 between T1 and T2). The ARS request may be sent in a MAC message, an RRC message, or with reuse of CSI reporting resources on the PCell or any other serving cell.

[0072] Optionally, T ARS_req Also, T is used when the CSI reporting resource on the PCell is used to transmit the request. L1-RSRP,reporting The UE 110 may determine a time period threshold, i.e., T ARS_req_threshold It may be possible to initiate a request within

[0073] For example, a request may be sent from UE 110 at T2. The request may include at least beam information for which ARS is expected, e.g., SSB ID #1. It may also include an ARS index and the number of bursts expected for ARS if ARS is configured for the SCell before activation of the SCell.

[0074] Upon receiving the ARS request, the gNB 120 may trigger an ARS on the indicated DL beam corresponding to SSB ID#1 (at T3) or on the indicated ARS (if an ARS index is indicated). A TCI indication may be sent in the same MAC CE to indicate the DL beam to be monitored by the UE 110. The period between T2 and T3 is T MAC-uncertainty It can be called.

[0075] The UE 110 may then receive the ARS burst during the period 304 between T3 and T4. After the UE completes cell synchronization (e.g., AGC and time / frequency synchronization) based on the ARS, the UE may measure the SP-CSI-RS or periodic CSI-RS during the period 305 between T4 and T5 and send a CSI report for the SCell (at T5).

[0076] Optionally, the SP-CSI-RS may be activated in the same MAC CE of the ARS / TCI activation to avoid additional MAC uncertainty time. In another option, if the UE 110 indicates that the ARS is also used for CSI measurement, the UE 110 may skip the SP-CSI-RS measurement and send a CSI report based on the ARS.

[0077] In some exemplary embodiments, UE 110 may transmit a CSI report based on measurements on an ARS burst (not shown). The network may begin scheduling the UE after receiving the CSI report.

[0078] In the example shown in Figure 3B, similar to Figure 3A, the UE 110 receives an SCell activation command to activate an unknown SCell at the beginning of the timeline (i.e., T0). ARS_req (i.e., the period 312 between T1 and T2). The ARS request can be sent in a MAC message, an RRC message, or in a PCell or SCell with CSI reporting resource reuse. For example, ARS_reqAlso, if the CSI reporting resource on the PCell is used to transmit the request, T L1-RSRP,reporting The request may then be sent from UE 110 at T2.

[0079] In this case, the UE can request ARS transmission on multiple candidate beams, for example, based on its implementation information, such as Rx beam configuration or panel information. As shown in FIG. 3B, the UE 110 can request ARS on beams corresponding to SSBs #1 and #2. In one option, the UE 110 can indicate whether the same ARS is transmitted on multiple beams or whether each ARS is transmitted on a single beam. The gNB 120 can activate ARS on two beams for cell synchronization.

[0080] Alternatively, or optionally, the gNB 120 may also transmit the ARS on multiple beams without a UE request. The gNB 120 may transmit the ARS on multiple beams based on the most recent received measurement report from the UE.

[0081] Unlike the example of FIG. 3A, the UE needs to indicate the beam on which cell synchronization is completed based on the ARS. The gNB 120 can indicate the TCI indication (at T3) and activate the SP-CSI-RS for subsequent channel measurements. In the example of FIG. 3B, the ARS burst is transmitted on multiple beams, which extends the period of cell synchronization (period 314) compared to the period of a single ARS (period 304 in FIG. 3A). However, it still saves activation time by avoiding the beam sweep time, i.e., 8*Tr for SCells with unknown frequency ranges (FR2).

[0082] After the UE completes cell synchronization (e.g., time / frequency synchronization) based on the ARS, the UE may measure the SP-CSI-RS or periodic CSI-RS during the period 315 between T4 and T5 and send a CSI report for the SCell (at T5).

[0083] In the example shown in Figure 3C, similar to Figures 3A and 3B, the UE 110 receives an SCell activation command to activate an unknown SCell at the beginning of the timeline (i.e., T0). In this case, the UE may have detected the cell but does not have accurate beam information for the SCell, e.g., does not have valid L3 measurements for the SCell. In this case, as in Figure 3C, the UE needs to read the SSB index (during period 322) to obtain the beam information (i.e., SSB index) before sending an ARS request to the network. Then, for an additional time T ssb-index A period 322, which may be referred to as a period 322, is required for reading the SSB index on the SCell. Other operations or processes similar or the same as those in Figures 3A and 3B are omitted here.

[0084] In another example, the UE may not have detected a cell at the time of SCell activation (not shown). In this case, the UE may need to perform SSB-based cell detection and obtain an SSB index before it can initiate an ARS request. The activation delay may not be any different from the current SCell activation process.

[0085] In some exemplary embodiments, the activation time for ARS transmission, i.e., T activation_time can be defined based on the activation steps proposed above. For example, if the UE supports the UE-requested ARS capability, T activation_time is T L1-RSRP,reporting +T FirstATRS +T MAC-uncertainty +5ms, where T FirstATRS is a slot

number

[0086] In this way, a mechanism for triggering the ARS may be achieved to help the UE perform AGC and frequency and time tracking, and / or other activation steps on the SCell in a shorter period of time.

[0087] 4 shows a flowchart of an example method 400 of ARS-based SCell activation, according to some example embodiments of the present disclosure. Method 400 may be implemented in first device 110 as shown in FIG. 1. For illustrative purposes, method 400 will be described with reference to FIG. 1.

[0088] At 410, the first device 110 transmits a request to the second device to trigger transmission of an aperiodic reference signal based on available beam information upon activation of the secondary cell.

[0089] In some demonstrative embodiments, the first device may report to the second device the ability to support the request at the first device.

[0090] In some exemplary embodiments, the request is sent in at least one of a MAC message, an RRC message, or reuse of channel state information reporting resources in the primary cell or the active serving cell.

[0091] In some demonstrative embodiments, when a first device receives a command for activation of a secondary cell from a second device, the first device may transmit a request within a predetermined period of time.

[0092] In some exemplary embodiments, the predetermined period is the period for reporting Layer 1 reference signal received power when a channel state information reporting resource on the primary cell or the active serving cell is used to transmit the request.

[0093] In some demonstrative embodiments, if beam information is available, the first device may transmit a request indicating at least the aperiodic reference signal to be triggered on the beam.

[0094] In some demonstrative embodiments, if beam information is not available and a secondary cell to be activated is detected, the first device may determine at least one preferred beam based on a synchronization signal block index and transmit a request indicating at least an aperiodic reference signal to be triggered on the at least one preferred beam.

[0095] In some exemplary embodiments, if beam information is not available and a secondary cell to be activated has not been detected, the first device may perform cell detection for activation of the secondary cell.

[0096] In some exemplary embodiments, the request includes at least one of at least one preferred beam on which the one or more aperiodic reference signals are expected to be transmitted, the number of bursts of the one or more aperiodic reference signals expected on the at least one preferred beam, the configuration of the one or more aperiodic reference signals, or the use of bursts for secondary cell activation.

[0097] In some exemplary embodiments, the at least one preferred beam is indicated by at least one synchronization signal block index acquired by the first device or at least one of a respective aperiodic channel state information reference signal indexes associated with the at least one preferred beam, and the aperiodic channel state information reference signal is configured prior to activation of the secondary cell.

[0098] At 420, the first device receives an aperiodic reference signal for activation of the secondary cell.

[0099] In some demonstrative embodiments, the first device may receive an indication of a transmission configuration indication state associated with a transmission from the second device and monitor an aperiodic reference signal based at least on the indication.

[0100] In some demonstrative embodiments, the first device may receive an activation of a semi-periodic channel state information reference signal or a configuration of a periodic channel state information reference signal along with an indication of a transmission configuration indication status or an aperiodic reference signal.

[0101] In some demonstrative embodiments, the first device may generate a channel state information report based on measurements of at least one of an aperiodic reference signal, a semi-periodic channel state information reference signal, or a periodic channel state information reference signal, and transmit the channel state information report.

[0102] In some demonstrative embodiments, the first device may comprise a terminal device and the second device may comprise a network device.

[0103] 5 shows a flowchart of an example method 500 of ARS-based SCell activation, according to some example embodiments of the present disclosure. Method 500 may be implemented in second device 120 as shown in FIG. 1. For illustrative purposes, method 500 will be described with reference to FIG. 1.

[0104] At 510, the second device receives a request from the first device to trigger transmission of an aperiodic reference signal generated by the first device based on beam information available upon activation of the secondary cell.

[0105] At 520, the second device triggers transmission of an aperiodic reference signal to the first device for activation of the secondary cell.

[0106] In some demonstrative embodiments, the second device may receive from the first device a capability to support the request at the first device.

[0107] In some exemplary embodiments, the request is sent in at least one of a MAC message, an RRC message, or reusing channel state information reporting resources in the primary cell or the active serving cell.

[0108] In some exemplary embodiments, the request includes at least one of at least one preferred beam on which the one or more aperiodic reference signals are expected to be transmitted, the number of bursts of the one or more aperiodic reference signals expected on the at least one preferred beam, the configuration of the one or more aperiodic reference signals, or the use of bursts for secondary cell activation.

[0109] In some exemplary embodiments, the at least one preferred beam is indicated by at least one synchronization signal block index acquired by the first device or at least one of a respective aperiodic channel state information reference signal indexes associated with the at least one preferred beam, and the aperiodic channel state information reference signal is configured prior to activation of the secondary cell.

[0110] In some demonstrative embodiments, the second device may transmit to the first device an indication of a transmission setting indication state associated with the transmission.

[0111] In some demonstrative embodiments, the second device may transmit to the first device an activation of a semi-periodic channel state information reference signal or a configuration of a periodic channel state information reference signal along with an indication of the transmission configuration indication status or aperiodic reference signal.

[0112] In some demonstrative embodiments, the second device may receive from the first device a channel state information report generated by the first device based on at least one of an aperiodic reference signal, a semi-periodic channel state information reference signal, or a periodic channel state information reference signal.

[0113] In some exemplary embodiments, the first device comprises a terminal device and the second device comprises a network device.

[0114] In some demonstrative embodiments, an apparatus capable of performing method 400 (e.g., implemented in first device 110) may include means for performing each step of method 400. The means may be implemented in any suitable form. For example, the means may be implemented in a circuit or a software module.

[0115] In some demonstrative embodiments, the apparatus may include means for transmitting a request to a second device to trigger transmission of an aperiodic reference signal based on beam information available upon activation of the secondary cell, and means for receiving the aperiodic reference signal for activation of the secondary cell.

[0116] In some demonstrative embodiments, an apparatus capable of performing method 500 (e.g., implemented in second device 120) may include means for performing each step of method 500. The means may be implemented in any suitable form. For example, the means may be implemented in a circuit or a software module.

[0117] In some demonstrative embodiments, the apparatus includes means for receiving, from a first device, a request to trigger transmission of an aperiodic reference signal generated by the first device based on beam information available upon activation of a secondary cell, and means for performing to trigger transmission of the aperiodic reference signal to the first device for activation of the secondary cell.

[0118] 6 is a simplified block diagram of a device 600 suitable for implementing an exemplary embodiment of the present disclosure. The device 600 may be provided to implement a communication device, such as the terminal device 110 or the network device 120 shown in FIG. 1. As shown, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processors 610, and one or more communication modules 640 coupled to the processors 610.

[0119] The communications module 640 is for two-way communication. The communications module 640 has one or more communications interfaces to facilitate communication with one or more other modules or devices. The communications interface may represent any interface necessary for communication with other network elements. In some demonstrative embodiments, the communications module 640 may include at least one antenna.

[0120] The processor 610 may be of any type suitable for a local technology network and may include, by way of non-limiting example, one or more of a general purpose computer, a special purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The device 600 may have multiple processors, such as application specific integrated circuit chips that are time-slaved to a clock that synchronizes the main processor.

[0121] The memory 620 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memory include, but are not limited to, read-only memory (ROM) 624, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), optical disks, laser disks, and other magnetic and / or optical storage. Examples of volatile memory include, but are not limited to, random access memory (RAM) 622 and other volatile memory that does not persist during power-down durations.

[0122] The computer program 630 includes computer-executable instructions that are executed by the associated processor 610. The instructions of the program 630 may include instructions for performing the operations / acts of some example embodiments of the present disclosure. The program 630 may be stored in a memory, such as the ROM 624. The processor 610 may perform any appropriate actions and processes by loading the program 630 into the RAM 622.

[0123] An exemplary embodiment of the present disclosure may be implemented by a program 630 such that the device 600 may execute any process of the present disclosure, as discussed with reference to Figures 2 to 5. An exemplary embodiment of the present disclosure may also be implemented by hardware or a combination of software and hardware.

[0124] In some exemplary embodiments, the program 630 may be tangibly contained in a computer-readable medium, which may be included in the device 600 (such as memory 620) or other storage device accessible by the device 600. The device 600 may load the program 630 from the computer-readable medium into RAM 622 for execution. In some exemplary embodiments, the computer-readable medium may include any type of non-transitory storage medium, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. The term "non-transitory" as used herein is a limitation of the medium itself (i.e., tangible as opposed to a signal) as opposed to a limitation to data storage permanence (e.g., RAM vs. ROM).

[0125] 7 shows an example of a computer readable medium 700, which may be in the form of a CD, DVD or other optical storage disc. The computer readable medium 700 has the program 630 stored thereon.

[0126] In general, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic, or any combination thereof. While some aspects may be implemented in hardware, other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. While various aspects of the embodiments of the present disclosure are illustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it should be understood that the blocks, apparatus, systems, techniques, or methods described herein may be implemented in, by way of non-limiting example, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller, or other computing device, or some combination thereof.

[0127] Some exemplary 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 computer-executable instructions, such as those included in program modules, that execute on a target physical or virtual processor device to perform any of the methods described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or divided among program modules as desired in various embodiments. The machine-executable instructions for a program module may be executed in a local or distributed device. In a distributed device, the program modules may be located in both local and remote storage media.

[0128] Program code for carrying out the 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, a special-purpose computer, or other programmable data processing apparatus, such that when executed by the processor or controller, the program code implements the functions / acts specified in the flowcharts and / or block diagrams. The program code may run entirely on the machine, partially on the machine, as a stand-alone software package, partially on the machine, partially on a remote machine, or entirely on a remote machine or server.

[0129] In the context of the present disclosure, computer program code or associated data may be carried by any suitable carrier to enable a device, apparatus, or processor to perform the various processes and operations as described above. Examples of carriers include signals, computer-readable media, etc.

[0130] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. The computer-readable medium may include, but is 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 computer-readable storage media include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination thereof.

[0131] Furthermore, while operations are shown in a particular order, this should not be understood as requiring such operations to be performed in the particular order shown, or in any sequential order, or that all of the shown operations be performed, to achieve desirable results. In some situations, multitasking and parallel processing may be advantageous. Similarly, while some specific implementation details are included in the above description, these should not be construed as limitations on the scope of the disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated otherwise, 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 otherwise, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination.

[0132] Although the present disclosure has been described in language specific to structural features and / or methodological acts, it is to be understood that the present disclosure, as defined by 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

1. sending a request from the first device to the second device to trigger transmission of an aperiodic reference signal based on beam information available upon activation of the secondary cell; and receiving the aperiodic reference signal for activation of the secondary cell.

2. 10. The method of claim 1, further comprising reporting to the second device the capability to support the request at the first device.

3. The request is Medium Access Control messages, a radio resource control message, or 2. The method of claim 1, wherein the channel state information is transmitted with at least one of a reuse of channel state information reporting resources in a primary cell or an active serving cell.

4. The step of sending the request comprises:

2. The method of claim 1, further comprising: transmitting the request within a predetermined period of time in accordance with determining that a command for activation of the secondary cell is received from the second device.

5. 5. The method of claim 4, wherein the predetermined period is a period for reporting Layer 1 reference signal received power when a channel state information reporting resource on a primary cell or an active serving cell is used to transmit the request.

6. The step of sending the request comprises:

2. The method of claim 1, further comprising: transmitting, to the second device, the request indicating at least the aperiodic reference signal to be triggered on a preferred beam in accordance with a determination that beam information is available.

7. The step of sending the request comprises: determining at least one preferred beam based on a synchronization signal block index in accordance with a determination that beam information is not available and the secondary cell to be activated has been detected; and transmitting to the second device the request indicating at least the aperiodic reference signal to be triggered on the at least one preferred beam.

8. The step of sending the request comprises:

2. The method of claim 1, further comprising: performing cell detection for activation of the secondary cell in accordance with a determination that beam information is not available and the secondary cell to be activated has not been detected.

9. The request is at least one preferred beam over which one or more aperiodic reference signals are expected to be transmitted; the number of bursts of the one or more aperiodic reference signals expected on the at least one preferred beam; the configuration of the one or more aperiodic reference signals; or 2. The method of claim 1, comprising at least one of using the burst for activation of the secondary cell.

10. The at least one priority beam At least one synchronization signal block index obtained by the first device; 10. The method of claim 9, wherein the aperiodic channel state information reference signal index associated with the at least one preferred beam is indicated by at least one of the aperiodic channel state information reference signal indexes that are set before activation of the secondary cell.

11. receiving, from the second device, an indication of a transmission configuration indication state related to the transmission of the aperiodic reference signal; 2. The method of claim 1, further comprising: monitoring the aperiodic reference signal based at least on the indication.

12. 2. The method of claim 1, further comprising receiving an indication of a transmission configuration indication status or the aperiodic reference signal together with activation of a semi-periodic channel state information reference signal or configuration of a periodic channel state information reference signal.

13. the aperiodic reference signal; a semi-periodic channel state information reference signal, or generating a channel state information report based on at least one measurement of a periodic channel state information reference signal; 13. The method of claim 12, further comprising: transmitting the channel state information report.

14. 10. The method of claim 1, wherein the first device comprises a terminal device and the second device comprises a network device.

15. receiving, at a second device, a request from a first device to trigger transmission of an aperiodic reference signal generated by the first device based on beam information available upon activation of a secondary cell; and performing the transmission of the aperiodic reference signal to the first device for activation of the secondary cell so as to be triggered.

16. 16. The method of claim 15, further comprising receiving from the first device a capability to support the request at the first device.

17. The request is Medium Access Control messages, a radio resource control message, or 16. The method of claim 15, wherein the channel state information is received in at least one of a reuse of a channel state information reporting resource in a primary cell.

18. The request is at least one preferred beam over which one or more aperiodic reference signals are expected to be transmitted; the number of bursts of the one or more aperiodic reference signals expected on the at least one preferred beam; Configuring the one or more aperiodic reference signals; or 16. The method of claim 15, comprising at least one of using the burst for activation of the secondary cell.

19. The at least one priority beam At least one synchronization signal block index obtained by the first device; 20. The method of claim 18, wherein the aperiodic channel state information reference signal index associated with the at least one preferred beam is indicated by at least one of the aperiodic channel state information reference signal indexes that are set before activation of the secondary cell.

20. 16. The method of claim 15, further comprising transmitting to the first device an indication of a transmission configuration indication state related to the transmission of the aperiodic reference signal.

21. 16. The method of claim 15, further comprising transmitting to the first device an indication of a transmission configuration indication status of the aperiodic reference signal or activation of a semi-periodic channel state information reference signal or configuration of a periodic channel state information reference signal.

22. From the first device: the aperiodic reference signal; a semi-periodic channel state information reference signal, or 22. The method of claim 21, further comprising receiving a channel state information report generated by the first device based on at least one periodic channel state information reference signal.

23. 16. The method of claim 15, wherein the first device comprises a terminal device and the second device comprises a network device.

24. at least one processor; and at least one memory for storing instructions which, when executed by the at least one processor, cause the device to perform at least a method according to at least one of claims 1 to 14 or at least one of claims 15 to 23.

25. Apparatus, characterized in that it comprises means for carrying out the method according to at least one of claims 1 to 14 or the method according to at least one of claims 15 to 23.

26. A non-transitory computer readable medium comprising program instructions for causing an apparatus to at least perform the method according to at least one of claims 1 to 14 or the method according to at least one of claims 15 to 23.

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