WO2025171535A1

WO2025171535A1 - Measurement on secondary cell

Info

Publication number: WO2025171535A1
Application number: PCT/CN2024/077211
Authority: WO
Inventors: Naizheng ZHENG; Lei Du; Tao Tao
Original assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Current assignee: Nokia Shanghai Bell Co Ltd; Nokia Solutions and Networks Oy; Nokia Technologies Oy
Priority date: 2024-02-14
Filing date: 2024-02-14
Publication date: 2025-08-21
Anticipated expiration: 2026-08-14

Abstract

Example embodiments of the present disclosure are related to measurement on a carrier aggregation (CA) cell. A first apparatus receives, from a second apparatus, a request to perform a measurement on a second cell which is different from a first cell serving the first apparatus. The request is comprised in downlink control information. The first apparatus then provides, to the second apparatus, an indication indicating whether a result of the measurement meets at least one condition.

Description

MEASUREMENT ON SECONDARY CELL

FIELD

Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to methods, devices, apparatuses and a computer readable storage medium for measurement on a carrier aggregation (CA) cell.

BACKGROUND

An Synchronization Signal Block (SSB) is an essential part of the 5G New Radio (NR) standard used for wireless communication. It plays a crucial role in synchronizing user devices (UEs) with the 5G network and enabling efficient cell search and initial access procedures. The SSB may be a periodically always-on signal. However, this is not desired for network energy saving for new radio (NR) .

SUMMARY

In a first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: receive, from a second apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus; and provide, to the second apparatus, an indication indicating whether or not result of the measurement meets at least one predetermined condition, wherein the request is comprised in downlink control information.

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 at least to: transmit, to a first apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus; receive, from the first apparatus, an indication indicating whether or not a result of the measurement meets at least one predetermined condition; and determine, based on the indication, whether or not a synchronization signal on the second cell is to be transmitted, wherein the request is comprised in downlink control information.

In a third aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a second apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus; and providing, to the second apparatus, an indication indicating whether or not a result of the measurement meets at least one predetermined condition, wherein the request is comprised in downlink control information.

In a fourth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a first apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus; receiving, from the first apparatus, an indication indicating whether a result of the measurement meets at least one predetermined condition; and determining, based on the indication, whether or not a synchronization signal on the second cell is to be transmitted, wherein the request is comprised in downlink control information.

In a fifth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a second apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus; and means for providing, to the second apparatus, an indication indicating whether or not a result of the measurement meets at least one predetermined condition, wherein the request is comprised in downlink control information.

In a sixth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for transmitting, to a first apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus; means for receiving, from the first apparatus, an indication indicating whether a result of the measurement meets at least one predetermined condition; and means for determining, based on the indication, whether or not a synchronization signal on the second cell is to be transmitted, wherein the request is comprised in downlink control information.

In a seventh 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 third aspect.

In an eighth 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 fourth aspect.

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

Some example embodiments may now be described with reference to the accompanying drawings, where:

FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

FIG. 2 illustrates a signaling flow for measurement on CA secondary Cell (SCell) according to some example embodiments of the present disclosure;

FIG. 3 illustrates a schematic diagram of measurement procedure on CA SCell according to some example embodiments of the present disclosure;

FIG. 4 illustrates a flowchart of a method implemented at a first apparatus according to some example embodiments of the present disclosure;

FIG. 5 illustrates a flowchart of a method implemented at a second apparatus according to some example embodiments of the present disclosure;

FIG. 6 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

FIG. 7 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

Throughout the drawings, the same or similar reference numerals represent the same or similar element.

DETAILED DESCRIPTION

Principle of the present disclosure may 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 may be implemented in various manners other than the ones described below.

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.

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.

It may 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.

As used herein, “at least one of the following: <a list of two or more elements>” and “at least one of <a list of two or more elements>” 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.

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.

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 may 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.

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.

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.

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) , 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 may 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.

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

The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE) , a Subscriber Station (SS) , a Portable Subscriber Station, a Mobile Station (MS) , or an Access Terminal (AT) . The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA) , portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE) , laptop-mounted equipment (LME) , USB dongles, smart devices, wireless customer-premises equipment (CPE) , an Internet of Things (IoT) 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.

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 may 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.

FIG. 1 illustrates example communication environment 100 in which example embodiments of the present disclosure can be implemented. In the communication environment 100, a plurality of communication devices, including a first apparatus 110 and a second apparatus 120 can communicate with each other.

The first apparatus 110 may be located in one or more cells managed by the second apparatus 120 and/or other apparatuses. In the communication environment 100, the second apparatus 120 may communicate data and control information with the first apparatus 110 in one or more cells, such as a cell 101 and a cell 102.

As shown in FIG. 1, the second apparatus 120 has CA capability and may transmit to and receive from the cell 101 and the cell 102. One of the cells 101 and 102 may be a primary cell (PCell) and the other may be a SCell. In this example environment 100, it is assumed that the cell 101 is the PCell and the cell 102 is the SCell. It is to be understood that this is just an example, rather than suggesting any limitation. There may be more SCells and the cell may be a PCell in some other embodiments.

Still referring to the example environment 100, the PCell 101 is a cell that operates on the primary frequency band. A terminal device, for example, the first apparatus 110, may conduct an initial connection establishment process or begin the connection re-establishment process in the PCell. Once the terminal device is in a Radio Resource Control (RRC) connected state, it may be configured with one or more SCells. The SCell 102 operates on the secondary frequency band and is configured to provide additional wireless resources.

In some example embodiments, if the first apparatus 110 is a terminal device and the second apparatus 120 is a network device, a link from the second apparatus 120 to the first apparatus 110 is referred to as a downlink (DL) , while a link from the first apparatus 110 to the second apparatus 120 is referred to as an uplink (UL) . In DL, the second apparatus 120 is a transmitting (TX) device (or a transmitter) and the first apparatus 110 is a receiving (RX) device (or a receiver) . In UL, the first apparatus 110 is a TX device (or a transmitter) and the second apparatus 120 is a RX device (or a receiver) .

It is to be understood that the number of apparatuses and their connections shown in FIG. 1 are only for the purpose of illustration without suggesting any limitation. The communication environment 100 may include any suitable number of apparatuses configured to implementing example embodiments of the present disclosure.

In the following, for purpose of illustration, some example embodiments are described with the first apparatus 110 operating as a terminal device and the second apparatus 120 operating as a network device. However, in some example embodiments, operations described in connection with a terminal device may be implemented at a network device or other device, and operations described in connection with a network device may be implemented at a terminal device or other device.

Communications in the communication environment 100 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) , 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.

Study and research are made on the inter-band CA with synchronization signal block (SSB) -less SCell operation. However, the focused scenario is only limited to the Frequency Range (FR) 1 and co-located inter-band CA, where the inter-band CA with non-co-located or band combination of FR1-FR2 scenarios was not being studied.

As briefly mentioned above, the inter-band CA with non-co-located or band combination of FR1-FR2 scenarios is to be further developed.

Firstly, it is desired to specify procedures and signaling method (s) to support on-demand SSB SCell operation for UEs in connected mode configured with CA, for both intra-/inter-band CA. For example, specify triggering method (s) (select from UE uplink wake-up-signal using an existing signal/channel, cell on/off indication via backhaul, SCell activation/deactivation signaling) . It should be noted that on-demand SSB transmission can be used by UE for at least SCell time/frequency synchronization, (layer 1) L1/ (layer 3) L3 measurements and SCell activation, and is supported for FR1 and FR2 in non-shared spectrum.

Secondly, it is desired to study procedures and signaling method (s) to support on-demand System Information Block 1 (SIB1) for UEs in idle/inactive mode, including: triggering method by uplink wake-up-signal using an existing signal/channel; wake-up-signal configuration provisioning to UE; information exchange between gNBs at least for the configuration of wake-up signal, if necessary.

Thirdly, it is desired to specify adaptation of common signal/channel transmissions, for example, adaptation of SSB in time domain, e.g., adapting periodicity; adaptation of Physical Random Access Channel (PRACH) in time domain; adaptation of PRACH in spatial domain, e.g. non-uniform PRACH resources per SSB, and specify if found beneficial; adaptation of paging occasions including confining the paging occasions in the time domain.

Fourthly, it is desired to specify the corresponding core requirements, for the above features.

Generally, it is understood that the above-mentioned first objective covers not only on-demand SSB operation for SSB-less SCell scenario but also on-demand SSB operation for the SCell where SSB-less operation is not feasible. Moreover, with the “on-demand SSB” SCell operation, technically the “on-demand SSB” transmission can be based on either network (NW) triggered manner or UE triggered approach. And with the on-demand SSB transmission in SCell operation, further adaptation of time-domain SSB patterns can considered as stated in the above-mentioned third objective, which can help to further reduce the network energy consumption by enabling more chances for gNB to use deeper sleep mode, and in the meanwhile, it enables faster SCell activation for the SCell with on-demand SSB transmission if the SCell is in rather deep sleep mode.

Generally, an RRC_CONNECTED UE with CA, is required to perform cell detection and corresponding measurement, i.e. automatic gain control (AGC) tuning, time and frequency synchronization, and Layer 1 Reference Signal Receiver Power (L1-RSRP) measurement, before data transmissions on CA SCell. For R15/16 CA operation, the measurements are based on the SSB signal transmissions on SCell, and further enhancement was made with R17 CA to reduce the latency of SCell Activation procedure, where the measurements with AGC and time/frequency (T/F) synchronization can be based on an NW triggered tracking reference signal (TRS) burst transmissions with SCell Activation command. But still, the cell detection measurements need to be performed based on legacy periodic SSB signal on SCell.

Furthermore, for CA with SSB-less SCell operation, the transmission of SSB signals on CA SCell is minimized with one of motivations for network energy saving. And the RRC_CONNECTED CA UE relies on the SSB measurement from PCell or reference cell to acquire the cell detection and corresponding measurements for AGC tuning and T/F synchronization. Practically, such SSB-less SCell operation can work fine under the Intra-band contiguous CA scenario, since collocation deployment has been assumed for intra-band CA, and therefore it can be assumed that the channel characteristic among the contiguous intra bands carriers can be quite similar or even the same, and the timing and AGC derived from the SSB based measurements in PCell/reference cell can be assumed directly applicable to the SSB-less SCell.

In existing design, SCell activation delay requirement is defined for SSB-less Intra-band SCell. As described below, only 3ms is needed to activate an intra-band SSB-less SCell as the UE assumes the same timing, beam information and channel propagation conditions with PCell. Hence no dedicated activation steps are needed for the SCell. UE blindly relies on that network uses exactly same configuration and timing. And applying this the UE would start using the SCell. However, this requirement is defined under a list of additional side conditions including receive time difference (RTD) at the UE side, power difference (at UE side) and Quasi-Colocation (QCL) status. Taking RTD as example, the receive time difference between the serving cell (e.g. PCell) and the to be activated SCell, needs to be within 260ns (as observed at by the UE) . The current 260ns maximum receive timing difference (MRTD) requirement is based on intra-band contiguous CA where the current MRTD is based on the network phase synchronization requirement of 260ns and assuming that the PL delay difference between the PCell and the SCell being activated is assumed negligible (zero) .

It is specified that if the SCell being activated belongs to FR1 and if there is at least one active serving cell contiguous to the SCell on that FR1 band, if the UE is not provided with SSB configuration (absoluteFrequencySSB) nor SMTC configuration for the target SCell, Tactivation_time is 3 ms for UE supporting scellWithoutSSB, provided the following side conditions:

- The RTD between the target SCell and the contiguous active serving cell is within±260ns, and

- The difference of the reception power with the contiguous active serving cell is <= 6dB, and

- The RS (s) of SCell being activated is (are) QCL-TypeA with TRS (s) of the SCell being activated, and the TRS (s) of the SCell being activated is (are) further QCL- TypeC with SSB (s) of any active serving cell that is contiguous to the SCell being activated on that FR1 band.

However, such SSB-less SCell operation can be problematic for RRC connected UEs with inter-band CA scenario, for example when the CA carriers between the bands are co-located/non-co-located, or non-contiguous intra-band CA. In these scenarios, the channel characteristic, i.e. Path Loss (PL) delay, reflections, and PL loss, measured in the PCell or reference cell band can no longer be assumed the same and may be quite different from the other CA bands. In this case, the SSB-based measurements in PCell/reference cell of an RRC connected CA UE cannot be assumed directly applicable to the other SCell/carriers. And therefore, it requires some signals (i.e. SSB or ATRS) transmissions on SCell for assisting UE to measure the SCell such as with cell detection, AGC tuning, T/F synchronization, L1-RSRP etc.

By practice, the network has the freedom to configure the CA SCell, and even an SSB-less SCell if the network decides to go to the network saving mode. However, with SSB-less SCell operation especially for the scenario of co-located inter-band CA and non-contiguous intra-band CA, the network as well as the UE does not have the prior-knowledge on whether or not the measurements from the PCell/reference cell can be applicable to the configured SSB-less SCell, unless the UE can perform some sort of measurement evaluation or verification based on the signal transmissions in SSB-less SCell. This measurement evaluation or verification may be associated with whether or not the above-mentioned side conditions are met/satisfied.

Practically, such verification signal in SCell can be based on the legacy NW configured SSB with always-ON periodic transmissions. However, from network saving perspective, it is not a very NW energy efficient approach. A better alternative to obtain network energy saving is that the SCell operate in SSB-less mode with network-triggered on-demand SSB transmissions whenever the NW requires the UE to perform such measurement evaluation or verification in the operation of SSB-less SCell.

In legacy Long Term Evolution (LTE) /NR network, the network pooling with PDCCH order was specified, where originally the Physical Downlink Control Channel (PDCCH) order is a mechanism by which the gNB “force” the UE to initiate PRACH. Practically, one of the most important purposes of RACH is to let UE obtain the synchronization with network and establish the initial connection pipe. In most case, the decision to initiate (trigger) PRACH is done by UE side. But there is some case where Network (eNB) need to “force” UE to initiate the RACH, and PDCCH Order is the mechanism.

For PDCCH order with NR, the Downlink Control Information (DCI) format 1_0 was specified with details of corresponding DCI fields described below, where the network may “force” the UE to perform random access procedure with PRACH transmission in the indicated SSB-beam and/or UL/SUL carrier.

DCI format 1_0 is used for the scheduling of PDSCH in one downlink (DL) cell. The following information is transmitted by means of the DCI format 1_0 with CRC scrambled by Cell Radio-Network Temporary Identifier (C-RNTI) or Configured Scheduling RNTI (CS-RNTI) or Modulation Coding Scheme Cell RNTI (MCS-C-RNTI) :

- Identifier for DCI formats -1 bits;

- The value of this bit field is always set to 1, indicating a DL DCI format;

- Frequency domain resource assignment -bits whereis given by the following: 1) the size of CORESET 0 if CORESET 0 is configured for the cell; and 2) the size of initial DL bandwidth part if CORESET 0 is not configured for the cell.

If the Cyclic Redundancy Check (CRC) of the DCI format 1_0 is scrambled by C-RNTI and the "Frequency domain resource assignment" field are of all ones, the DCI format 1_0 is for random access procedure initiated by a PDCCH order, with all remaining fields set as follows:

- Random Access Preamble index -6 bits according to ra-PreambleIndex.

- UL/supplementary uplink (SUL) indicator -1 bit. If the value of the "Random Access Preamble index" is not all zeros and if the UE is configured with supplementaryUplink in ServingCellConfig in the cell, this field indicates which UL carrier in the cell to transmit the PRACH; otherwise, this field is reserved.

- Synchronization Signal (SS) /Synchronization Signal (PBCH) index -6 bits. If the value of the "Random Access Preamble index" is not all zeros, this field indicates the SS/PBCH that shall be used to determine the RACH occasion for the PRACH transmission; otherwise, this field is reserved.

- PRACH Mask index -4 bits. If the value of the "Random Access Preamble index" is not all zeros, this field indicates the RACH occasion associated with the SS/PBCH indicated by "SS/PBCH index" for the PRACH transmission; otherwise, this field is reserved.

- Reserved bits -12 bits for operation in a cell with shared spectrum channel access in frequency range 1 or when the DCI format is monitored in common search space for operation in a cell in frequency range 2-2, otherwise 10bits.

Furthermore, details about RACH with PDCCH order in NR are provided below. The Random Access procedure is initiated by a PDCCH order, by the MAC entity itself, or by RRC for the predetermined events. There is only one Random Access procedure ongoing at any point in time in a Media Access Control (MAC) entity. The Random Access procedure on an SCell or an Layer 1 or Layer 2 (L1/L2) triggered mobility (LTM) candidate cell shall only be initiated by a PDCCH order with ra-PreambleIndex different from 0b000000.

It should be noted that if a new Random Access procedure is triggered while another is already ongoing in the MAC entity, it is up to UE implementation whether to continue with the ongoing procedure or start with the new procedure (e.g. for SI request) . Moreover, if there was an ongoing Random Access procedure that is triggered by a PDCCH order while the UE receives another PDCCH order indicating the same Random Access Preamble, PRACH mask index and uplink carrier, the Random Access procedure is considered as the same Random Access procedure as the ongoing one and not initialized again.

According to some example embodiments of the present disclosure, there is provided a solution for UE measurement in CA SCell. To identify whether the side conditions are met (e.g. timing from the PCell/reference cell can be applicable to the configured SSB-less Scell) , especially for the scenario of co-located inter-band CA and non-contiguous intra-band CA, the NW may request the UE to perform such measurement evaluation or verification in the operation of SSB-less SCell, i.e. before SCellConfig, with better network energy efficient manner. This may help network to decide if SSB-less operation can be configured on the SCell. Solution (s) for triggering such measurements based on PDCCH Order mechanism are proposed and descried in details below.

Example embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings.

FIG. 2 illustrates a signaling flow 200 for UE measurement on CA SCell according to some example embodiments of the present disclosure. For the purposes of discussion, the signaling flow 200 will be discussed with reference to FIG. 1. The signaling flow involves a first apparatus 110 and a second apparatus 120. For the purpose of illustration, some example embodiments may be described with the first apparatus 110 operating as a terminal device (for example, a UE) and the second apparatus 120 operating as a network device (for example, a gNB) .

In the signaling flow 200, the second apparatus 120 transmits (215) a request to the first apparatus 110. The request is intended to trigger the first apparatus 110 to perform a measurement on a second cell. The second cell is different from a first cell serving the first apparatus 110. In some example embodiments, the first cell may be a PCell, for example, the cell 101 and the second cell may be a SCell, for example, the cell 102. In such case, the second apparatus 120 may send the request in PCell to the first apparatus 110 and may request the first apparatus 110 to perform evaluation/verification measurements in an intended SSB-less SCell, for example, the second cell.

The request may be included in downlink control information (DCI) . In some example embodiments, the DCI may include the physical downlink control channel (PDCCH) order command. Specifically, the DCI format of the “PDCCH order” may be based on the DCI format 1_0. In this case, the request may be also referred to as a PDCCH order or a PDCCH order command.

The request may have various structure. In some example embodiments, the request may include an uplink (UL) /supplemental uplink (SUL) field. The UL/SUL field may correspond to the second cell on which the first apparatus is to perform the measurement. In such case, the intended SSB-less SCell for UE measurement is indicated via the legacy field of UL/SUL indicator in DCI format 1_0.

Alternatively or in addition, the request may include a SSB index field. The SSB index field may correspond to a SSB beam in the second cell on which the first apparatus is to perform the measurement. The second apparatus 120 may utilize the SSB index fields to request the first apparatus 110 to perform the measurements in the indicated SSB beam only. If the field is absent, the first apparatus 110 may need to perform the measurements in all SSB beams as default.

In some further example embodiments, the request may further include a field dedicated for indicating to perform the measurement. With a new bit-field for indication of the purpose of PDCCH order, the DCI may instruct the first apparatus 110 to perform evaluation and verification measurement in the intended SSB-less SCell i.e. the second cell.

The request may include a variety of indications or information. In some example embodiments, the request may include, for example but not limited to, an indication indicating whether the measurement is to be performed, an indication of a beam on which the measurement is performed, an indication of a type of the measurement, an indication of a signal to be measured, and/or an indication of a time duration for providing the indication and the like.

Additionally, the second apparatus 120 may transmit (205) configuration information to the first apparatus 110. The configuration information may indicate, for example but not limited to, a list of beams among which at least one is instructed/requested to be measured, a list of types of measurement among which at least one is instructed/requested to be performed, a list of signals among which at least one is instructed/requested to be measured, a list of time durations for providing the indication, and/or a list of conditions associated with a measurement and so on. For example, the configuration information may be transmitted via system information.

In such case, the second apparatus 120 may indicate in the request an index or entry of a list of network configured verification signals (i.e. type of verification signals (SSB vs. CSI-RS) , periodicity, duration, starting offset, etc. ) that is utilized, if the list of network configured verification signals are carried in broadcast system information (SIB) . That is, the second apparatus 120 may indicate in the request the expected type of UE feedback and/or measurement, if the list of UE measurement types are configured in SIB.

In some example embodiments, the configuration information may be included in system information or a message of RRC received on the first cell.

The first apparatus 110 may receive (210) the configuration information. Thus, the first apparatus 110 may have the knowledge of configured beams and/or signals to be possibly measured, types of possible measurements, possible time durations for providing the indication, conditions associated with the measurement, and/or the like. In some example embodiments, the request received (220) by the first apparatus 110 may indicate, for example, which one of the configured beams is to be measured, which one of the signals is to be measured, which one of the types of measurement is to be used, which time duration of the time durations is to be used, and/or which one of the conditions are to be applied.

As shown in FIG. 2, the first apparatus 110 receives (220) the request and performs measurements accordingly. Then, the first apparatus 110 provides (225) an indication (which is also referred to as a UE feedback) to the second apparatus 120. The indication indicates whether a result of the measurement meets at least one predetermined condition (also referred to as “side condition” in some example embodiments) . The indication may be an explicit “Yes” or “No” , or may be an implicit “No” (which may correspond to a case where no indication is transmitted when the at least one condition is not met. The message carrying the indication may additionally or alternatively include any result (s) of the at least one measurement. The at least one condition may be, for example but not limited to, whether a received time difference (RTD) of signals between PCell and SCell is within a cyclic prefix (CP) , and/or whether a received power level per resource element (EPRE) of the SCell is within a threshold from the reference cell (for example PCell) . etc., as explained above in connection of additional side conditions.

In some example embodiments, upon the PDCCH order is received from the second apparatus 120 with DCI format 1_0, the first apparatus 110 may perform the measurement of the configured verification signals in the intended SSB-less SCell based on the PDCCH order with DCI format 1_0. The first apparatus 110 may then evaluate on whether the given at least one conditions are fulfilled or not based on measurement results of the configured verification signal and may feedback to the second apparatus 120 on the measurement results based on a PDCCH order triggering.

In some example embodiments, the indication may be transmitted (225) in a message of Medium Access Control (MAC) control element (CE) . Alternatively, the indication may be transmitted (225) in a message of Radio Resource Control (RRC) . Alternatively, the indication may be transmitted (225) in a message of Layer-1 signal or a message carried in a Layer-1 uplink control channel or uplink data channel. The Layer-1 signal may be PRACH for example. In such case, the UE feedback may be based on PRACH signal, which indicates to the second apparatus 120 “Yes” (the at least one condition is fulfilled) , or “No” (the at least one condition is not fulfilled) . Alternatively, an implicit “No” can be considered. More specifically, if the first apparatus 110 does not feedback PRACH before a timer (e.g., T) expired, the second apparatus 120 may treat it as “No” (the at least one condition is not fulfilled) . The timer T may be preconfigured to the first apparatus 110 or indicated via the PDCCH order.

In some example embodiments, the indication may be transmitted within a time duration for providing the indication after receiving the request. The time duration may be predetermined or may be obtained from the request or configuration information. In some example embodiments, the first apparatus 110 may transmit, to the second apparatus, the result of the measurement via a preconfigured resource, a Medium Access Control (MAC) command, or a Radio Resource Control (RRC) message.

Specifically, the indication (possible carrying measurement results reporting) is transmitted via some L1 resources, L2 MAC command, or L3 report. For carrying the indication, the PUCCH/PUSCH resource (s) can be configured in the serving cell (PCell) . The first apparatus 110 may be able to send the indication based on the PDCCH order triggering within a certain time period. This is defined as the PDCCH-order triggered measurement reporting delay i.e. the time between the PDCCH order and the point when the first apparatus 110 starts to transmit the indication over an air interface. The time for transmission of such PUCCH/PUSCH triggered by PDCCH order can be a fixed timing, i.e. a timer or a configured timing based PUCCH/PUSCH transmission.

In further example embodiments, the time duration may be based on a type of measurement to be performed. Alternatively, or in addition, the time duration may be based on a processing time for processing downlink control information and/or a measuring time for performing the measurement and evaluating the result of the measurement. That is, the reporting delay may be determined based on at least the following: 1) a processing time for process the PDCCH order, for instance, a fixed timing that is defined and/or 2) a measurement/evaluation time for determining if the at least one condition is fulfilled.

When the measurement period is defined, two cases need to be considered. In the first case, namely, Case1, if the first apparatus 110 has been configured with neighbor cell measurement on the SCell, the first apparatus 110 has detected the SCell and is able to measure quite soon after receiving PDCCH order (i.e. the request) . The measurement period can be defined as the time to measure e.g. RTD. It is determined based on a number of measurement samples, measurement occasions (e.g. SMTC) , verification signal periodicity, discontinuous reception (DRX) cycle etc.

In the second case, namely, Case 2, if the first apparatus 110 has not been configured with neighbor cell measurement on the SCell, the first apparatus 110 would need identify the SCell which takes longer time than case 1 (assuming verification signaling can also be used for cell identification) . The cell identification time needs to be additional counted in the reporting delay.

The second apparatus 120 receives (230) the indication from the first apparatus 110 and determines (235) whether or not an ScellConfig message and/or a synchronization signal on the second cell is to be transmitted. The determination is based on the indication. In some example embodiments, based on the UE feedback with PDCCH order mechanism, the second apparatus 120 may decide whether to configure the SSB-less SCell to the first apparatus 110 with sending of SCellConfig message or not. The first apparatus 110 may receive the configuration of a synchronization signal to be transmitted on the second cell if the indication indicating the at least one condition is not fulfilled.

Specifically, if the indication received (230) from the first apparatus 110 indicates that the result of the measurement does not meet the at least one condition, the second apparatus 120 may determine that a synchronization signal needs to be transmitted on the second cell. Then, the second apparatus 120 may determine a configuration of the synchronization signal to be transmitted on the second cell. In turn, the second apparatus 120 may transmit, to the first apparatus 110, the configuration of the synchronization signal on the second cell. On the other hand, if the indication indicates that the result of the measurement meets the at least one condition, the second apparatus 120 may determine that a synchronization signal need not be transmitted on the second cell (in which case configuration of the synchronization signal need not be transmitted) .

In some example embodiment, the configuration of the synchronization signal on the second cell may include, for example but not limited to, a periodicity of the synchronization signal, a starting point of the synchronization signal, a transmission duration of the synchronization signal, and/or an allocated time frequency resource for the synchronization signal.

In some example embodiment, the first apparatus 110 may include a terminal device, and the second apparatus 120 may include a network device. The first cell may be a PCell and the second cell may be a SCell.

In view of the above, a mechanism for triggering UE measurements in CA SCell based on the PDCCH order is proposed. FIG. 3 illustrates a schematic diagram of a measurement procedure on CA SCell according to some example embodiments of the present disclosure. For the purposes of discussion, the schematic diagram 300 will be discussed with reference to FIG. 1. The schematic diagram 300 involves a first apparatus 110 and a second apparatus 120. For the purpose of illustration, some example embodiments may be described with the first apparatus 110 operating as a terminal device (for example, a UE) and the second apparatus 120 operating as a network device (for example, a gNB) .

As shown in FIG. 3. the second apparatus 120 requests or triggers the first apparatus 110 (e.g., an RRC_CONNECTED UE) with CA capability to perform measurement evaluation or verification before intended SSB-less SCell configuration/operation based on the PDCCH order, for example, in DCI format 1_0. Then, the first apparatus 110 performs the measurement of the configured verification signals, for example, tracking reference signals (TRSs) in TRS burst (s) , in the intended SSB-less SCell triggered by the PDCCH order. Then, the first apparatus 110 transmits a corresponding feedback from the first apparatus 110 to the second apparatus 120, so as to assist the second apparatus 120 to determine whether the intended SCell can be appliable to the UE with SSB-less or not. The second apparatus 120 may determine whether or not transmit a SCellConfig message and/or a synchronization signal to the first apparatus 110 based on the feedback from the first apparatus 110. In an embodiment, the configuration of the synchronization signal is included in the SCellConfig.

FIG. 4 shows a flowchart of an example method 400 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 400 will be described from the perspective of the first apparatus 110 in FIG. 1.

At block 410, the first apparatus 110 receives, from a second apparatus 120, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus 110. The request is comprised in downlink control information.

At block 420, the first apparatus 110 provides , to the second apparatus 120, an indication indicating whether a result of the measurement meets at least one condition.

In some example embodiments, the downlink control information comprises a physical downlink control channel (PDCCH) order command.

In some example embodiments, the request comprises at least one of the following fields: an uplink (UL) /supplemental uplink (SUL) field corresponding to the second cell on which the first apparatus is to perform the measurement, a synchronization signal /physical broadcast channel (SSB) index field corresponding to the SSB beam in the second cell on which the first apparatus is to perform the measurement, or a field dedicated for indicating to perform the measurement.

In some example embodiments, the request indicates at least one of the following: an indication indicating whether the measurement is to be performed, an indication of a beam on which the measurement is performed, an indication of a type of the measurement, an indication of a signal to be measured, or an indication of a time duration for providing the indication.

In some example embodiments, the first apparatus 110 may further receive, from the second apparatus, configuration information indicating at least one of: a list of beams among which at least one is instructed to be measured, a list of types of measurement among which at least one is instructed to be performed, a list of signals among which at least one is instructed to be measured, a list of time durations for providing the indication, or a list of conditions associated with a measurement.

In some example embodiments, the configuration information is comprised in system information or a message of Radio Resource Control (RRC) received on the first cell.

In some example embodiments, the indication is transmitted in at least one of: a message of Medium Access Control (MAC) control element (CE) , a message of Radio Resource Control (RRC) , a message of Layer-1 signal or a message carried in a Layer-1 uplink control channel or uplink data channel.

In some example embodiments, the indication is transmitted within a time duration for providing the indication after receiving the request, wherein the time duration is predetermined or is obtained from the request or configuration information.

In some example embodiments, the time duration is based on a type of measurement to be performed.

In some example embodiments, the time duration is based on at least one of a processing time for processing downlink control information, a measuring time for performing the measurement and evaluating the result of the measurement.

In some example embodiments, the first apparatus 110 may further transmit, to the second apparatus, the result of the measurement via a preconfigured resource, a Medium Access Control (MAC) command, or a Radio Resource Control (RRC) message.

In some example embodiments, the first apparatus 110 may further receive, from the second apparatus, a configuration of a synchronization signal to be transmitted on the second cell, the configuration being determined in a case where the indication indicates the result of the measurement does not meet the at least one condition.

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

FIG. 5 shows a flowchart of an example method 500 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 500 will be described from the perspective of the second apparatus 120 in FIG. 1.

At block 510, the second apparatus 120 transmits, to a first apparatus 110, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus.

At block 520, the second apparatus 120 receives, from the first apparatus 110, an indication indicating whether a result of the measurement meets at least one condition.

At block 530, the second apparatus 120 determines, based on the indication, whether or not a synchronization signal on the second cell is to be transmitted, the request is comprised in downlink control information.

In some example embodiments, the second apparatus 120 may further transmit, to the first apparatus, configuration information indicating at least one of: a list of beams among which at least one is instructed to be measured , a list of types of measurement among which at least one is instructed to be performed, a list of signals among which at least one is instructed to be measured, a list of time durations for providing the indication, or a list of conditions associated with a measurement.

In some example embodiments, the indication is transmitted in at least one of: a message of Medium Access Control (MAC) control element (CE) , a message of Radio Resource Control (RRC) , or a message of Layer-1 signal or a message carried in a Layer-1 uplink control channel or uplink data channel.

In some example embodiments, the indication is received within a time duration for providing the indication after transmitting the request, wherein the time duration is predetermined or is obtained from the request or configuration information.

In some example embodiments, the time duration is based on at least one of a processing time for processing downlink control information, or a measuring time for performing the measurement and evaluating the result of the measurement.

In some example embodiments, the second apparatus 120 may further receive, from the first apparatus, the result of the measurement via a preconfigured resource, a Medium Access Control (MAC) command, or a Radio Resource Control (RRC) message.

In some example embodiments, the second apparatus 120 may further: in accordance with a determination that the indication indicates that the result of the measurement does not meet the at least one condition, determine that a synchronization signal needs to be transmitted on the second cell; determine a configuration of the synchronization signal to be transmitted on the second cell; and transmit, to the first apparatus, the configuration of the synchronization signal on the second cell.

In some example embodiments, the second apparatus 120 may further: in accordance with a determination that the indication indicates that the result of the measurement meets the at least one condition, determine that a synchronization signal need not be transmitted on the second cell.

In some example embodiments, the configuration of the synchronization signal on the second cell comprises at least one of: a periodicity of the synchronization signal, a starting point of the synchronization signal, a transmission duration of the synchronization signal, or an allocated time frequency resource for the synchronization signal.

In some example embodiments, a first apparatus capable of performing any of the method 400 (for example, the first apparatus 110 in FIG. 1) may comprise means for performing the respective operations of the method 400. 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. 1.

In some example embodiments, the first apparatus comprises means for receiving, from a second apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus, wherein the request is comprised in downlink control information; and means for providing, to the second apparatus, an indication indicating whether a result of the measurement meets at least one condition.

In some example embodiments, the first apparatus further comprises means for performing other operations in some example embodiments of the method 400 or the first apparatus 110. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the first apparatus.

In some example embodiments, a second apparatus capable of performing any of the method 500 (for example, the second apparatus 120 in FIG. 1) may comprise means for performing the respective operations of the method 500. 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. 1.

In some example embodiments, the second apparatus comprises means for transmitting, to a first apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus, wherein the request is comprised in downlink control information; means for receiving, from the first apparatus, an indication indicating whether a result of the measurement meets at least one condition; and means for determining, based on the indication, whether or not a synchronization signal on the second cell is to be transmitted.

In some example embodiments, the second apparatus further comprises means for performing other operations in some example embodiments of the method 500 or the second apparatus 120. In some example embodiments, the means comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the performance of the second apparatus.

FIG. 6 is a simplified block diagram of a device 600 that is suitable for implementing example embodiments of the present disclosure. The device 600 may be provided to implement a communication device, for example, the first apparatus 110 or the second apparatus 120 as shown in FIG. 1. As shown, the device 600 includes one or more processors 610, one or more memories 620 coupled to the processor 610, and one or more communication modules 640 coupled to the processor 610.

The communication module 640 is for bidirectional communications. The communication module 640 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 640 may include at least one antenna.

The processor 610 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 600 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.

The memory 620 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) 624, 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) 622 and other volatile memories that will not last in the power-down duration.

A 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 operations/acts of some example embodiments of the present disclosure. The program 630 may be stored in the memory, e.g., the ROM 624. The processor 610 may perform any suitable actions and processing by loading the program 630 into the RAM 622.

The example embodiments of the present disclosure may be implemented by means of the program 630 so that the device 600 may perform any process of the disclosure as discussed with reference to FIG. 2 to FIG. 7. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

In some example embodiments, the program 630 may be tangibly contained in a computer readable medium which may be included in the device 600 (such as in the memory 620) or other storage devices that are accessible by the device 600. The device 600 may load the program 630 from the computer readable medium to the RAM 622 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) .

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

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.

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 computer-executable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

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.

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.

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

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.

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

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 at least to:

receive, from a second apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus, wherein the request is comprised in downlink control information; and

provide, to the second apparatus, an indication indicating whether or not a result of the measurement meets at least one predetermined condition.
The first apparatus of claim 1, wherein the downlink control information comprises a physical downlink control channel (PDCCH) order command.
The first apparatus of any of claims 1 to 2, wherein the request comprises at least one of the following fields:

an uplink (UL) /supplemental uplink (SUL) field corresponding to the second cell on which the first apparatus is to perform the measurement,

a synchronization signal /physical broadcast channel (SSB) index field corresponding to the SSB beam in the second cell on which the first apparatus is to perform the measurement, or

a field dedicated for indicating to perform the measurement.
The first apparatus of any of claims 1 to 3, wherein the request indicates at least one of the following:

an indication indicating whether the measurement is to be performed,

an indication of a beam on which the measurement is performed,

an indication of a type of the measurement,

an indication of a signal to be measured, or

an indication of a time duration for providing the indication.
The first apparatus of any of claims 1 to 4, wherein the first apparatus is caused to:

receive, from the second apparatus, configuration information indicating at least one of:

a list of beams among which at least one is instructed to be measured,

a list of types of measurement among which at least one is instructed to be performed,

a list of signals among which at least one is instructed to be measured,

a list of time durations for providing the indication, or

a list of conditions associated with a measurement.
The first apparatus of claim 5, wherein the configuration information is comprised in system information or a message of Radio Resource Control (RRC) received on the first cell.
The first apparatus of any of claims 1 to 6, wherein the indication is transmitted in at least one of:

a message of Medium Access Control (MAC) control element (CE) ,

a message of Radio Resource Control (RRC) ,

a message of Layer-1 signal or a message carried in a Layer-1 uplink control channel or uplink data channel.
The first apparatus of any of claims 1 to 7, wherein the indication is transmitted within a time duration for providing the indication after receiving the request, wherein the time duration is predetermined or is obtained from the request or configuration information.
The first apparatus of claim 8, wherein the time duration is based on a type of measurement to be performed.
The first apparatus of any of claims 8 to 9, wherein the time duration is based on at least one of a processing time for processing downlink control information, or a measuring time for performing the measurement and evaluating the result of the measurement.
The first apparatus of any of claims 1 to 10, wherein the first apparatus is caused to:

transmit, to the second apparatus, the result of the measurement via a preconfigured resource, a Medium Access Control (MAC) command, or a Radio Resource Control (RRC) message.
The first apparatus of any of claims 1 to 11, wherein the first apparatus is caused to:

receive, from the second apparatus in a case where the indication indicates that the result of the measurement does not meet the at least one condition, a configuration of a synchronization signal to be transmitted on the second cell.
The first apparatus of any of claims 1 to 12, wherein the first apparatus comprises a terminal device, and the second apparatus comprises a network device.
A second apparatus comprising:

at least one processor; and

at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to:

transmit, to a first apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus, wherein the request is comprised in downlink control information;

receive, from the first apparatus, an indication indicating whether or not a result of the measurement meets at least one predetermined condition; and

determine, based on the indication, whether or not a synchronization signal on the second cell is to be transmitted.
The second apparatus of claim 14, wherein the downlink control information comprises a physical downlink control channel (PDCCH) order command.
The second apparatus of any of claims 14 to 15, wherein the request comprises at least one of the following fields:

an uplink (UL) /supplemental uplink (SUL) field corresponding to the second cell on which the first apparatus is to perform the measurement,

a synchronization signal /physical broadcast channel (SSB) index field corresponding to the SSB beam in the second cell on which the first apparatus is to perform the measurement, or

a field dedicated for indicating to perform the measurement.
The second apparatus of any of claims 14 to 16, wherein the request indicates at least one of the following:

an indication indicating whether the measurement is to be performed, an indication of a beam on which the measurement is performed,

an indication of a type of the measurement,

an indication of a signal to be measured, or

an indication of a time duration for providing the indication.
The second apparatus of any of claims 14 to 176, wherein the second apparatus is caused to:

transmit, to the first apparatus, configuration information indicating at least one of:

a list of beams among which at least one is instructed to be measured ,

a list of types of measurement among which at least one is instructed to be performed,

a list of signals among which at least one is instructed to be measured,

a list of time durations for providing the indication, or

a list of conditions associated with a measurement.
The second apparatus of claim 18, wherein the configuration information is comprised in system information or a message of Radio Resource Control (RRC) received on the first cell.
The second apparatus of any of claims 14 to 19, wherein the indication is transmitted in at least one of:

a message of Medium Access Control (MAC) control element (CE) ,

a message of Radio Resource Control (RRC) , or

a message of Layer-1 signal or a message carried in a Layer-1 uplink control channel or uplink data channel.
The second apparatus of any of claims 14 to 20, wherein the indication is received within a time duration for providing the indication after transmitting the request, wherein the time duration is predetermined or is obtained from the request or configuration information.
The second apparatus of claim 21, wherein the time duration is based on a type of measurement to be performed.
The second apparatus of any of claims 21 to 22, wherein the time duration is based on at least one of a processing time for processing downlink control information, or a measuring time for performing the measurement and evaluating the result of the measurement.
The second apparatus of any of claims 14 to 23, wherein the second apparatus is caused to:

receive, from the first apparatus, the result of the measurement via a preconfigured resource, a Medium Access Control (MAC) command, or a Radio Resource Control (RRC) message.
The second apparatus of any of claims 14 to 24, wherein the second apparatus is caused to:

in accordance with a determination that the indication indicates that the result of the measurement does not meet the at least one condition, determine that a synchronization signal needs to be transmitted on the second cell;

determine a configuration of the synchronization signal to be transmitted on the second cell; and

transmit, to the first apparatus, the configuration of the synchronization signal on the second cell.
The second apparatus of any of claims 14 to 24, wherein the second apparatus is caused to:

in accordance with a determination that the indication indicates that the result of the measurement meets the at least one condition, determine that a synchronization signal need not be transmitted on the second cell.
The second apparatus of claim 25, wherein the configuration of the synchronization signal on the second cell comprises at least one of:

a periodicity of the synchronization signal,

a starting point of the synchronization signal,

a transmission duration of the synchronization signal, or

an allocated time frequency resource for the synchronization signal.
The second apparatus of any of claims 14 to 27, wherein the first apparatus comprises a terminal device, and the second apparatus comprises a network device.
A method comprising:

receiving, from a second apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus, wherein the request is comprised in downlink control information; and

providing, to the second apparatus, an indication indicating whether a result of the measurement meets at least one predetermined condition.
A method comprising:

transmitting, to a first apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus, wherein the request is comprised in downlink control information;

receiving, from the first apparatus, an indication indicating whether a result of the measurement meets at least one predetermined condition; and

determining, based on the indication, whether or not a synchronization signal on the second cell is to be transmitted.
A first apparatus comprising:

means for receiving, from a second apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus, wherein the request is comprised in downlink control information; and

means for providing, to the second apparatus, an indication indicating whether a result of the measurement meets at least one predetermined condition.
A second apparatus comprising:

means for transmitting, to a first apparatus, a request to perform a measurement on a second cell, the second cell being different from a first cell serving the first apparatus, wherein the request is comprised in downlink control information;

means for receiving, from the first apparatus, an indication indicating whether a result of the measurement meets at least one predetermined condition; and

means for determining, based on the indication, whether or not a synchronization signal on the second cell is to be transmitted.
A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 29 or the method of claim 30.