Apparatus, method and apparatus for timing advance

Abstract

The embodiment of the invention discloses equipment, a method and a device for timing advance (TA). A terminal device receives, from a serving cell for the terminal device, a configuration for quasi-co-location (QCL) for one or more candidate cells of the terminal device. The terminal device then transmits a physical random access channel (PRACH) to at least one candidate cell among the one or more candidate cells. Further, the terminal device monitors a random access response (RAR) from the at least one candidate cell based on the configuration of the QCL for the at least one candidate cell.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to the field of communications, and in particular to devices, methods, apparatuses, and computer-readable storage media for timing advance. Background Art

[0002] In communication technology, there is an ongoing evolution to provide efficient and reliable solutions for utilizing wireless communication networks. Currently, efforts are underway to develop fifth-generation (5G) or 5G-advanced wireless systems. The new wireless systems can support various types of service applications for terminal devices.

[0003] In current wireless systems, a user equipment (UE) can send a physical random access channel (PRACH) to a network device acting as a candidate or non-serving cell in response to a physical downlink control channel (PDCCH) command to acquire the timing advance (TA) corresponding to the candidate or non-serving cell, and then wait for a random access response (RAR) from the network device, which includes the TA and is sent via downlink control information (DCI) scrambled with a random access radio network temporary identifier (RA-RNTI). The UE attempts to detect a PDCCH with the corresponding RA-RNTI from the base station within a window for receiving the RAR (e.g., referred to as the ra-ResponseWindow) to acquire the TA value. However, enhancements to the TA acquisition process are still under further study. Summary of the Invention

[0004] Generally, example embodiments of the present disclosure provide devices, methods, apparatuses, and computer-readable storage media for TA, particularly TA acquisition.

[0005] In a first aspect, a terminal device is provided. The terminal device includes: one or more transceivers; and one or more processors, the one or more processors being coupled to the one or more transceivers, wherein the one or more transceivers are configured, together with the one or more processors, to cause the terminal device to: receive, from a serving cell for the terminal device, a configuration of a quasi co-location (QCL) for one or more candidate cells of the terminal device; transmit a physical random access channel (PRACH) to at least one candidate cell among the one or more candidate cells; and monitor a random access response (RAR) from the at least one candidate cell based on the configuration of the QCL for the at least one candidate cell.

[0006] In a second aspect, a network device acting as a serving cell for a terminal device is provided. The network device comprises: one or more transceivers; and one or more processors, the one or more processors being coupled to the one or more transceivers, wherein the one or more transceivers are configured, together with the one or more processors, to cause the network device to: obtain a configuration for quasi co-location (QCL) of one or more candidate cells for the terminal device; and send the configuration of the QCL to the terminal device, so that the terminal device can receive a random access response (RAR) from at least one of the one or more candidate cells based on the configuration.

[0007] In a third aspect, a network device that acts as a candidate cell for a terminal device is provided. The network device comprises: one or more transceivers; and one or more processors, the one or more processors being coupled to the one or more transceivers, wherein the one or more transceivers are configured to, together with the one or more processors, cause the network device to: send a quasi-co-location (QCL) configuration associated with the candidate cell to a serving cell for the terminal device; receive a physical random access channel (PRACH) from the terminal device based on the QCL configuration; and send a random access response (RAR) to the terminal device.

[0008] In a fourth aspect, a method implemented at a terminal device is provided. The method comprises: receiving, from a serving cell for the terminal device, a configuration of a quasi co-location (QCL) for one or more candidate cells for the terminal device; sending a physical random access channel (PRACH) to at least one candidate cell among the one or more candidate cells; and monitoring a random access response (RAR) from the at least one candidate cell based on the configuration of the QCL for the at least one candidate cell.

[0009] In a fifth aspect, a method implemented at a network device acting as a serving cell for a terminal device is provided. The method comprises: obtaining a configuration of a quasi co-location (QCL) for one or more candidate cells for the terminal device; and sending the configuration of the QCL to the terminal device, so that the terminal device can receive a random access response (RAR) from at least one of the one or more candidate cells based on the configuration.

[0010] In a sixth aspect, a method implemented at a network device acting as a candidate cell for a terminal device is provided. The method comprises: sending a quasi-co-location (QCL) configuration associated with the candidate cell to a serving cell for the terminal device; receiving a physical random access channel (PRACH) from the terminal device based on the QCL configuration; and sending a random access response (RAR) to the terminal device.

[0011] In a seventh aspect, an apparatus of a terminal device is provided. The apparatus comprises: means for receiving, from a serving cell for the terminal device, a configuration of a quasi co-location (QCL) for one or more candidate cells of the terminal device; means for sending a physical random access channel (PRACH) to at least one candidate cell among the one or more candidate cells; and means for monitoring a random access response (RAR) from at least one candidate cell based on the configuration of the QCL for the at least one candidate cell.

[0012] In an eighth aspect, an apparatus of a network device acting as a serving cell for a terminal device is provided. The apparatus comprises: means for obtaining a configuration of a quasi co-location (QCL) for one or more candidate cells for the terminal device; and means for sending the configuration of the QCL to the terminal device so that the terminal device can receive a random access response (RAR) from at least one of the one or more candidate cells based on the configuration.

[0013] In a ninth aspect, an apparatus of a network device acting as a candidate cell for a terminal device is provided. The apparatus comprises: means for sending a quasi co-location (QCL) configuration associated with the candidate cell to a serving cell for the terminal device; means for receiving a physical random access channel (PRACH) from the terminal device based on the QCL configuration; and means for sending a random access response (RAR) to the terminal device.

[0014] In a tenth aspect, a terminal device is provided. The terminal device includes: at least one processor; and at least one memory, the at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the terminal device to: receive, from a serving cell for the terminal device, a configuration for quasi co-location (QCL) for one or more candidate cells of the terminal device; send a physical random access channel (PRACH) to at least one candidate cell among the one or more candidate cells; and monitor a random access response (RAR) from the at least one candidate cell based on the configuration of the (QCL) for the at least one candidate cell.

[0015] In an eleventh aspect, a network device acting as a serving cell for a terminal device is provided. The network device comprises: at least one processor; and at least one memory, the at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the network device to: obtain a configuration for quasi co-location (QCL) of one or more candidate cells for the terminal device; and send the configuration of the QCL to the terminal device, so that the terminal device can receive a random access response (RAR) from at least one of the one or more candidate cells based on the configuration.

[0016] In a twelfth aspect, a network device serving as a candidate cell for a terminal device is provided. The network device comprises: at least one processor; and at least one memory, the at least one memory comprising computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the network device to: send a quasi-co-location (QCL) configuration associated with the candidate cell to a serving cell for the terminal device; receive a physical random access channel (PRACH) from the terminal device based on the QCL configuration; and send a random access response (RAR) to the terminal device.

[0017] In a thirteenth aspect, a non-transitory computer-readable medium is provided, the non-transitory computer-readable medium comprising program instructions for causing an apparatus to at least perform the method according to any one of the fourth to sixth aspects.

[0018] In a fourteenth aspect, a computer program is provided, comprising instructions which, when executed by an apparatus at a terminal device, cause the apparatus to at least: receive, from a serving cell for the terminal device, a configuration of a quasi co-location (QCL) for one or more candidate cells for the terminal device; send a physical random access channel (PRACH) to at least one candidate cell among the one or more candidate cells; and monitor a random access response (RAR) from at least one candidate cell based on the configuration of the QCL for the at least one candidate cell.

[0019] In a fifteenth aspect, a computer program is provided, comprising instructions which, when executed by an apparatus at a network device acting as a serving cell for a terminal device, cause the apparatus to at least: obtain a configuration of a quasi co-location (QCL) for one or more candidate cells for the terminal device; and send the configuration of the QCL to the terminal device so that the terminal device can receive a random access response (RAR) from at least one of the one or more candidate cells based on the configuration.

[0020] In a sixteenth aspect, a computer program is provided, comprising instructions which, when executed by an apparatus at a network device acting as a candidate cell for a terminal device, cause the apparatus to at least: send a quasi-co-location (QCL) configuration associated with the candidate cell to a serving cell for the terminal device; receive a physical random access channel (PRACH) from the terminal device based on the QCL configuration; and send a random access response (RAR) to the terminal device.

[0021] In a seventeenth aspect, a terminal device is provided. The terminal device includes: a receiving circuit system configured to receive, from a serving cell for the terminal device, a configuration of a quasi co-location (QCL) for one or more candidate cells for the terminal device; a transmitting circuit system configured to transmit a physical random access channel (PRACH) to at least one candidate cell among the one or more candidate cells; and a monitoring circuit system configured to monitor a random access response (RAR) from at least one candidate cell based on the configuration of the QCL for the at least one candidate cell.

[0022] In an eighteenth aspect, a network device acting as a serving cell for a terminal device is provided. The network device comprises: an obtaining circuit system configured to obtain a configuration of a quasi co-location (QCL) for one or more candidate cells for the terminal device; and a transmitting circuit system configured to transmit the configuration of the QCL to the terminal device, so that the terminal device can receive a random access response (RAR) from at least one of the one or more candidate cells based on the configuration.

[0023] In a nineteenth aspect, a network device acting as a serving cell for a terminal device is provided. The network device comprises: a transmitting circuit system configured to transmit a quasi co-location (QCL) configuration associated with a candidate cell to the serving cell for the terminal device; a receiving circuit system configured to receive a physical random access channel (PRACH) from the terminal device based on the QCL configuration; and a transmitting circuit system configured to transmit a random access response (RAR) to the terminal device.

[0024] It should be understood that the invention summary is not intended to identify the key or essential features of the embodiments of the present disclosure, nor is it intended to limit the scope of the present disclosure. Other features of the present disclosure will become readily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Some example embodiments will now be described with reference to the accompanying drawings, in which:

[0026] Figure 1shows an example network environment in which example embodiments of the present disclosure may be implemented;

[0027] Figure 2 shows an example signal flow for TA acquisition according to some example embodiments of the present disclosure;

[0028] Figure 3 shows an example communication process according to some example embodiments of the present disclosure;

[0029] Figure 4 An example flow chart of a method implemented at a terminal device according to an example embodiment of the present disclosure is shown;

[0030] Figure 5 An example flow chart illustrating a method implemented at a network device acting as a serving cell according to some example embodiments of the present disclosure is shown;

[0031] Figure 6 An example flow chart illustrating a method implemented at a network device acting as a candidate cell according to some other example embodiments of the present disclosure is shown;

[0032] Figure 7 An example simplified block diagram illustrating a device suitable for implementing embodiments of the present disclosure; and

[0033] Figure 8 An example block diagram of an example computer-readable medium according to some embodiments of the present disclosure is shown.

[0034] Throughout the drawings, the same or similar reference numerals represent the same or similar elements. DETAILED DESCRIPTION

[0035] The principles of the present disclosure will now be described with reference to some example embodiments. It should be understood that these embodiments are described only for illustrative purposes and to help those skilled in the art understand and implement the present disclosure, without representing any limitation on the scope of the present disclosure. The present disclosure described herein can be implemented in a variety of ways different from those described below.

[0036] 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 skill in the art to which this disclosure belongs.

[0037] References in this disclosure to "one embodiment," "an embodiment," "an example embodiment," etc., indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes the particular feature, structure, or characteristic. Furthermore, such phrases are not necessarily referring to the same embodiment. Furthermore, when a particular feature, structure, or characteristic is described in conjunction with an embodiment, those skilled in the art recognize that it is within the knowledge of those skilled in the art to incorporate such feature, structure, or characteristic in conjunction with other embodiments (whether or not explicitly described).

[0038] It should be understood that although the terms "first" and "second" 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. For example, a first element may be referred to as a second element, and similarly, a second element may 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.

[0039] The terms used in this article are only used to describe the purpose of specific embodiments and are not intended to limit example embodiments. As used in this article, the singular forms "one", "an" and "the" are also intended to include their plural forms, unless the context clearly indicates otherwise. It will also be understood that the terms "comprise", "include", "have", "have", "include" and / or "comprising" specify the presence of the features, elements and / or components etc. when used in this article, but do not exclude the presence or addition of one or more other features, elements, components and / or their combinations. As used in this article, "at least one of the following: <list of two or more elements>" and "at least one of <list of two or more elements>" and similar wording, wherein the list of two or more elements is connected by "and" or "or", representing at least any one element, or at least any two or more elements, or at least all elements.

[0040] As used in this application, the term "circuitry" may refer to one or more or all of the following:

[0041] (a) hardware circuit implementation only (such as implementation only in analog and / or digital circuitry), and

[0042] (b) a combination of hardware circuitry and software such as (where applicable):

[0043] (i) a combination of analog and / or digital hardware circuits and software / firmware and

[0044] (ii) any portion of hardware processor(s) with software (including digital signal processor(s), software and memory(s) that work together to enable a device (such as a mobile phone or server) to perform various functions) and

[0045] (iii) Hardware circuit(s) and processor(s), such as microprocessor(s) or portion(s) of microprocessor(s), which require software (e.g., firmware) to operate, but in which case the software may not be present when not required for operation.

[0046] This definition of circuitry applies to all uses of the term in this application, including in any claims. As another example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portions of a hardware circuit or processor and their accompanying software and / or firmware. For example, the term circuitry also covers a baseband integrated circuit or processor integrated circuit for a mobile device, or a similar integrated circuit in a server, cellular network device, or other computing or networking device, if applicable to the particular claim element.

[0047] As used herein, the term "communication network" refers to a network that complies with any suitable communication standard, such as Long Term Evolution (LTE), Advanced LTE (LTE-A), Wideband Code Division Multiple Access (WCDMA), High Speed Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. In addition, the communication between the terminal equipment and the network equipment in the communication network can be performed according to any suitable generation communication protocol, including but not limited to the third generation communication protocol (3G), the fourth generation communication protocol (4G), 4.5G, the future fifth generation communication protocol (5G), and / or any other protocol currently known or to be developed in the future. The embodiments of the present disclosure can be applied to various communication systems. Due to the rapid development of communication, there will certainly be future types of communication technologies and systems that utilize them to implement the present disclosure. It should not be regarded as limiting the scope of the present disclosure to only the above-mentioned systems.

[0048] 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 from it. A network device may refer to a base station (BS) or an access point (AP), such as a Node B (NodeB or NB), an evolved Node B (eNodeB or eNB), a new radio (NR) NB (also known as a gNB), a remote radio unit (RRU), a radio head (RH), a remote radio head (RRH), a relay, a low-power node (such as a femto, pico, etc.), depending on the terminology and technology used.

[0049] The term "terminal device" refers to any terminal device 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, smart phones, voice over IP (VoIP) phones, wireless local loop phones, tablet computers, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image capture terminal devices (such as digital cameras), game terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEEs), laptop devices (LMEs), USB dongles, smart devices, wireless customer terminal equipment (CPEs), Internet of Things (IoT) devices, watches or other wearable devices, 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 process chain environments), consumer electronic devices, devices running on commercial and / or industrial wireless networks, etc. In the following description, the terms "terminal device", "communication device", "terminal", "user equipment" and "UE" may be used interchangeably.

[0050] As described above, during the random access procedure, the UE can transmit a PRACH to a network device acting as a candidate or non-serving cell to acquire a timing advance (TA), and wait for the RAR from the network device during the window period for receiving the RAR, which includes the TA and is transmitted via DCI scrambled with the RA-RNTI. The UE searches for DCI in the Type 1 PDCCH common search space. The PRACH can be a preamble or a combination of a preamble and data, depending on the PRACH type.

[0051] The DCI format used to schedule RAR on the physical downlink shared channel (PDSCH) may be DCI format 1_0 scrambled with the RA-RNTI. The resource allocation type for message 2 (Msg2) on the PDSCH may be resource allocation type 1. Frequency domain resource allocation for the PDSCH carrying the RAR message may be specified by DCI format 0_1. Time domain resource allocation for the PDSCH carrying the RAR message may be specified by DCI format 1 and PDSCH-ConfigCommon.

[0052] The window for receiving the RAR may start at the first symbol of the earliest control resource set (CORESET) of the Type 1 PDCCH common search space (CSS), which starts at least one symbol after the PRACH opportunity corresponding to the PRACH transmission. The window size for receiving the RAR may be configured in multiple time slots and may be less than 10 ms.

[0053] In the 3rd Generation Partnership Project (3GPP), there are some ongoing discussions in Release 18 (Rel-18). For example, two TAs are targeted for UL multi-DCI for multiple transmission reception points (multi-TRP) operation, and it is agreed to support the case where a PDCCH order sent by one TRP triggers a RACH procedure for at least the same TRP or different TRPs for inter-cell multi-DCI.

[0054] In addition, in the Rel-18 discussion, timing advance management was also proposed as a goal to specify the mechanisms and procedures for inter-cell mobility based on Layer 1 (L1) / Layer 2 (L2) for mobility latency reduction. In addition, both parties agreed that PDCCH orders should only be triggered by the source cell and that TA acquisition of (multiple) candidate cells should be supported before receiving a cell handover command based on L1 / L2 mobility.

[0055] Therefore, in the existing solution, for both inter-cell multiple transmission reception point (multi-TRP) operation and L1 / L2 mobility, the serving cell (i.e., source cell) sends a PDCCH command to trigger PRACH to the candidate cell (i.e., non-serving cell) to obtain the TA corresponding to the candidate cell.

[0056] However, backhaul between cells is not ideal and cell coordination can typically take time, which can lead to handover delays. Furthermore, if more than one candidate cell is considered for handover preparation, it is unclear how PRACH towards multiple cells should be performed and how RAR is received for each cell.

[0057] Furthermore, as described above, the UE starts monitoring the RAR in a window for receiving the RAR, which may start at the first symbol of the earliest CORESET of the Type 1 PDCCH CSS, where the earliest CORESET may start at least one symbol after the PRACH opportunity corresponding to the PRACH transmission.

[0058] The inventors have noted that if this conventional procedure is used, the serving cell may not be ready to send the RAR when the UE begins monitoring the RAR PDCCH. Therefore, there are still some issues with the RAR always being received from the serving cell. Furthermore, the inventors have noted that sending the RAR via a candidate cell appears to be an attractive technical option, and that an improved solution for accessing a candidate cell is needed.

[0059] In view of the above, embodiments of the present disclosure provide a new solution for TA acquisition. In this solution, a terminal device receives a configuration of a quasi-co-location (QCL) for one or more candidate cells of the terminal device from a serving cell for the terminal device. In addition, the terminal device transmits a PRACH to at least one of the one or more candidate cells. The terminal device then monitors the RAR from the at least one candidate cell based on the configuration of the QCL for the at least one candidate cell. Thus, the TA value corresponding to the candidate cell can be obtained.

[0060] By obtaining the configuration of the QCL for candidate cells from the serving cell, it is possible to enable RAR monitoring and reception, thereby improving TA acquisition via candidate cells, for example, for L1 / L2 mobility scenarios. At the same time, the proposed solution takes into account realistic assumptions about, for example, non-ideal backhaul between cells, making it possible to promote transmission efficiency for RAR monitoring and reception.

[0061] Hereinafter, the principles and embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Figure 1 , Figure 1 An example network environment 100 is shown in which example embodiments of the present disclosure may be implemented.

[0062] The network environment 100 may be part of a communication network and includes an end device 110 and a network device 120 that communicate with each other or with other devices via each other.

[0063] Network environment 100 may include any suitable number of devices and cells. In network environment 100, terminal device 110 and network device 120 may communicate data and control information to each other. The link from network device 120 to terminal device 110 is referred to as DL, while the link from terminal device 110 to network device 120 is referred to as UL.

[0064] It should be understood that the number of terminal devices 110 and the number of network devices 120 shown in the communication network environment 100 are for illustration purposes only and do not limit the scope of the present disclosure. In some example embodiments, the communication network environment 100 may include any number of terminal devices and / or any number of network devices.

[0065] Communications in the network environment 100 may follow any suitable communication standards or protocols that already exist or will be developed in the future, such as Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Fifth Generation (5G) New Radio (NR), Sixth Generation (6G) or above, Wireless Fidelity (Wi-Fi) and Worldwide Interoperability for Microwave Access (WiMAX) standards, and employ any suitable communication technology, including, for example, Multiple Input Multiple Output (MIMO), Orthogonal Frequency Division Multiplexing (OFDM), Time Division Multiplexing (TDM), Frequency Division Multiplexing (FDM), Code Division Multiplexing (CDM), Bluetooth, Zigbee and Machine Type Communication (MTC), Enhanced Mobile Broadband (eMBB), Massive Machine Type Communication (mMTC), Ultra-Reliable Low Latency Communication (URLLC), Carrier Aggregation (CA), Dual Connectivity (DC) and New Radio Unlicensed (NR-U) technology.

[0066] In some example embodiments, network device 120 (e.g., a serving cell) may provide at least one candidate cell to terminal device 110. In some example embodiments, network environment 100 may include another network device, and in this case, network device 120 may act as a serving cell for terminal device 110, and the other network device may act as a candidate cell for terminal device 110.

[0067] In some example embodiments, network device 120, acting as a serving cell, may transmit a configuration of a QCL for one or more candidate cells to terminal device 100. Terminal device 110 may receive a configuration of a QCL for one or more candidate cells for the terminal device from the serving cell for the terminal device. Terminal device 110 may transmit a PRACH to at least one of the one or more candidate cells. Network device 120, or another network device acting as a candidate cell, may receive the PRACH transmission and transmit a RAR including a TA value to terminal device 110. Terminal device 110 may then monitor the RAR from the candidate cells based on the configuration of the QCL for the candidate cells.

[0068] Figure 2 FIG2 shows an example signaling flow 200 of a random access procedure according to some example embodiments of the present disclosure. For the purpose of discussion, reference will be made to FIG200. Figure 1 A signaling flow 200 is described.

[0069] like Figure 2As shown, the candidate cell 203 of the terminal device 110 can send (205) the configuration of the QCL associated with the candidate cell 203 to the serving cell 201 of the terminal device 110. Therefore, the serving cell 201 obtains (210) the configuration of the QCL for the candidate cell 203 of the terminal device 110. For example, the serving cell 201 can obtain the configuration of the QCL from one or more other candidate cells respectively. Alternatively or in addition, the serving cell 201 can obtain the configuration of the QCL for one or more candidate cells (for example, including the candidate cell 203) for the terminal device 110 from the core network. It should be understood that before the candidate cell 203 sends the configuration of the QCL to the serving cell 201, the terminal device 110 can report the measurement results to the serving cell, and the report may include the measurement results for at least one of the serving cell and the candidate cell (for example, 203). The serving cell 201 can send the measurement results to each candidate cell respectively.

[0070] In some example embodiments, the configuration may indicate one or more QCL hypotheses for receiving a type 1 PDCCH CSS set containing a RAR for a terminal device. Each of the one or more QCL hypotheses may be associated with or correspond to a candidate cell (e.g., candidate cell 203). In other words, each QCL hypothesis (e.g., QCL type D) may correspond to a candidate cell to which the terminal device is expected to make a PRACH transmission.

[0071] For example, the QCL hypothesis associated with the candidate cell may correspond to a downlink reference signal associated with the candidate cell. The QCL hypothesis may be set to one of the QCL types including "Type A," "Type B," "Type C," or "Type D," which may be defined as follows:

[0072] - "Type A": {Doppler shift, Doppler spread, average delay, delay spread}

[0073] - "Type B": {Doppler shift, Doppler spread}

[0074] - "Type C": {Doppler shift, average delay}

[0075] - "Type D": {Spatial Rx Parameters}

[0076] For example, the QCL hypothesis associated with the candidate cell in the configuration may also be provided to the terminal device 110 so that the terminal device 110 can monitor the RAR from the candidate cell based on the QCL hypothesis.

[0077] like Figure 2As shown, the serving cell 201 sends (215) the QCL configuration to the terminal device 110, so that the terminal device 110 can receive the RAR from at least one candidate cell of the one or more candidate cells based on the configuration. Therefore, the terminal device 110 receives (220) the QCL configuration from the serving cell 201.

[0078] like Figure 2 As shown, the terminal device 110 transmits (225) a PRACH to the candidate cell 203. On the receiving side, the candidate cell 203 receives (230) a PRACH from the terminal device 110 based on the configuration of the QCL. For example, the PRACH may be received based on the QCL assumption associated with the candidate cell 203.

[0079] It should be noted that in Figure 2 In FIG, for illustration purposes, candidate cell 203 is shown as an example candidate cell that receives PRACH and sends RAR. Alternatively or additionally, the terminal device 110 may send PRACH to one or more other candidate cells.

[0080] In some example embodiments or on the other hand of the present disclosure, the terminal device 110 may obtain a TA from a candidate cell after receiving an explicit indication from the network device 120. For example, the serving cell 201 may send an indication to the terminal device 110 indicating that the terminal device 110 receives a RAR from one or more candidate cells. As another example, a candidate cell (e.g., candidate cell 203) may send an indication to the terminal device 110 indicating that the terminal device 110 receives a RAR from the candidate cell. Based on the received indication(s), the terminal device 110 may determine to send a PRACH to and receive a RAR from one or more candidate cells instead of the serving cell 201. The indication obtained from the network device 120 may not depend on Figure 2 In other words, receiving an indication indicating whether the terminal device 110 receives an RAR from the candidate cell 203 may be an independent embodiment, and the terminal device 110 may receive an RAR from the serving cell 201 or the candidate cell 203 according to the indication provided by the network device 120. In addition, the serving cell 201 may configure a QCL for at least one candidate cell together with the indication or separately.

[0081] The candidate cell 203 then sends (235) the RAR to the terminal device 110. The terminal device 110 therefore monitors (240) the RAR from the candidate cell based on the configuration of the QCL for the candidate cell 203.

[0082] In some example embodiments, the terminal device 110 may be configured with one or more Type 1 PDCCH CSS sets and one or more associated CORESETs. The one or more associated CORESETs may correspond to one or more QCL assumptions, respectively. In this case, the terminal device 110 may be configured / activated with more than one QCL assumption for receiving the Type 1 PDCCH CSS set. As an example, the terminal device may be configured with only one Type 1 PDCCH CSS set and one associated CORESET. As another example, the terminal device 110 may be configured with more than one Type 1 PDCCH CSS set and associated CORESET. These associated CORESETs may have different QCL assumptions.

[0083] As an example, the QCL hypothesis may be used to monitor the RAR after the last symbol of a PRACH opportunity corresponding to a transmission of the PRACH.For example, the terminal device 110 may switch from the QCL hypothesis associated with the serving cell 201 to the QCL hypothesis associated with the candidate cell 203.

[0084] Single candidate community case

[0085] In an example embodiment where there is one candidate cell (e.g., candidate cell 203), the terminal device 110 may monitor only the RAR from the candidate cell 203. In this case, following a PRACH transmission towards the candidate cell 203, the terminal device 110 may monitor the RAR using the QCL assumption associated with the candidate cell 203, e.g., during a window for monitoring the RAR. As an example, the terminal device 110 may attempt to detect DCI, e.g., format 1_0, having a cyclic redundancy check (CRC) scrambled by the RA-RNTI, during a window for monitoring the RAR controlled by higher layers by assuming the QCL assumption corresponding to the candidate cell 203.

[0086] For example, the candidate cell 203 may transmit a RAR after a PRACH opportunity corresponding to a transmission of a PRACH, and in this case, the QCL assumption associated with the candidate cell 203 may be used, for example, after the last symbol of the PRACH opportunity corresponding to the PRACH transmission. As an example, the terminal device 110 may change the QCL assumption of the CORESET associated with the Type 1 PDCCH CSS set after the last symbol of the PRACH opportunity corresponding to the PRACH transmission.

[0087] The terminal device 110 may then receive a RAR from the candidate cell 203. In some example embodiments, after receiving the RAR from the candidate cell 203 or expiry of the window for monitoring the RAR, the terminal device 110 may switch back to the QCL assumption associated with the serving cell 201 .

[0088] Multiple candidate community cases

[0089] In an example embodiment where there are multiple candidate cells, the multiple candidate cells may send RARs based on the QCL assumptions associated with the multiple candidate cells to the terminal device 110. The terminal device 110 may monitor the RARs from the multiple candidate cells.

[0090] The multiple candidate cells may include the candidate cell 203 and another candidate cell. In this case, after the PRACH transmission towards the candidate cell 203 and the another candidate cell, the terminal device 110 may monitor the RAR using the QCL assumptions associated with the candidate cell 203 and the another candidate cell, for example, during the window for monitoring the RAR. As an example, the terminal device 110 may attempt to detect a DCI of, for example, format 1_0, having a CRC scrambled by the RA-RNTI during the window for monitoring the RAR controlled by a higher layer by assuming the QCL assumptions corresponding to the candidate cell 203 and the another candidate cell, respectively.

[0091] In some example embodiments, the UE may change the QCL assumptions of the CORESET associated with the Type 1-PDCCH CSS set in a time division multiplexing (TDM) manner. For example, the RAR from candidate cell 203 and the RAR from another candidate cell may be sent in a TDM manner, and in this case, after the PRACH transmission, the QCL assumptions associated with candidate cell 203 and the other candidate cell may be used in a TDM manner.

[0092] As an example, a time window may be configured or defined for switching QCL assumptions. The terminal device 110 may monitor the RAR from the candidate cell 203 using the QCL assumption associated with the candidate cell 203 for the defined or configured time window, and then monitor the RAR from another candidate cell using another QCL assumption associated with the other candidate cell after the defined or configured time window.

[0093] The terminal device 110 may then receive RARs from the plurality of candidate cells and obtain a TA value.In some example embodiments, after receiving RARs from the plurality of candidate cells or expiry of a window for monitoring RARs, the terminal device 110 may switch back to the QCL assumption associated with the serving cell 201 .

[0094] It should be understood that although it is described that a cell sends or receives a message, it is the network equipment in the cell or providing the cell or serving the cell, so it is the network equipment that sends or receives the message.

[0095] In some example embodiments, serving cell 201 and candidate cell 203 may be managed by the same network device (e.g., network device 120). In some other example embodiments, serving cell 201 may be managed by one network device (e.g., network device 120), and candidate cell 203 may be managed by another network device.

[0096] Figure 3 FIG. 3 shows an example communication process 300 according to some example embodiments of the present disclosure. It should be understood that the process flow 300 can be viewed as follows: Figure 2 The signal flow 200 shown is an example. Thus, UE 301 may be an example of terminal device 110. Process flow 300 involves a serving cell 303 and a candidate cell 305, which may be provided by the same network device or different network devices.

[0097] like Figure 3 As shown, at 310, serving cell 303 sends a configuration / activation of a QCL hypothesis (e.g., QCL type D) for candidate cell 305 to UE 301. At 312, serving cell 303 may send a PDCCH command to UE 301 that triggers a PRACH transmission toward candidate cell 305. At 314, UE 301 may detect the PDCCH command and determine to perform a PRACH transmission toward candidate cell 305.

[0098] At 316, UE 301 may send a PRACH to candidate cell 305. At 318, UE 301 may switch the QCL Type D hypothesis for RAR monitoring. In this case, the QCL Type D associated with candidate cell 305 may be used to cache the CORESET associated with the Type 1 CSS. In the case when PRACH is sent to more than one candidate cell, a window may be defined or configured for switching QCL assumptions. For example, UE 301 may use the QCL hypothesis associated with candidate cell 203 for a defined or configured time window to monitor RAR from candidate cell 305, and then use another QCL hypothesis associated with another candidate cell after the defined or configured time window to monitor RAR from the other candidate cell.

[0099] At 320, candidate cell 305 may detect a PRACH transmission from UE 301. For example, candidate cell 305 may estimate an absolute TA or propagation delay. At 322, candidate cell 305 may determine a RAR towards UE 301, for example, using an associated QCL hypothesis for candidate cell 305.

[0100] At 324, the candidate cell 305 sends a RAR on the PDCCH based on the associated QCL assumption. At 326, the UE 301 detects the RAR on the PDCCH from the candidate cell 305 based on the associated QCL assumption.

[0101] Figure 4 FIG. 4 is an example flow chart of a method 400 implemented at a terminal device according to an example embodiment of the present disclosure. For the purpose of discussion, reference will be made to FIG. Figure 1 The method 400 is described from the perspective of the terminal device 110. It should be understood that although the method 400 has been described from the perspective of the terminal device 110, the method 400 may be performed by any other terminal device.

[0102] At 410, the terminal device 110 receives, from a serving cell for the terminal device 110, a configuration for a quasi co-location (QCL) for one or more candidate cells of the terminal device 110. At 420, the terminal device 110 transmits a physical random access channel (PRACH) to at least one of the one or more candidate cells. At 430, the terminal device 110 monitors a random access response (RAR) from the at least one candidate cell based on the configuration of the QCL for the at least one candidate cell.

[0103] In some example embodiments, terminal device 110 may also receive an indication from the serving cell indicating that terminal device 110 receives a RAR from at least one candidate cell.

[0104] In some example embodiments, terminal device 110 may also receive a RAR from at least one candidate cell.

[0105] In some example embodiments, the configuration may configure the terminal device 110 using one or more QCL hypotheses for receiving a type 1 physical downlink control channel (PDCCH) common search space (CSS) set containing RARs, and each of the one or more QCL hypotheses may be associated with a candidate cell.

[0106] In some example embodiments, the terminal device 110 may be configured with one or more Type 1 PDCCH CSS sets, and one or more associated control resource sets (CORESETs), and the one or more associated CORESETs may respectively correspond to one or more QCL hypotheses.

[0107] In some example embodiments, a QCL hypothesis associated with at least one candidate cell in the configuration may be used to monitor RAR.

[0108] In some example embodiments, the QCL assumption may be used to monitor the RAR after the last symbol of a PRACH opportunity corresponding to a transmission of the PRACH.

[0109] In some example embodiments, the at least one candidate cell may include at least a first candidate cell and a second candidate cell, and the terminal device 110 may further use QCL hypotheses associated with the first candidate cell and the second candidate cell for monitoring RAR after sending the PRACH.

[0110] In some example embodiments, the QCL hypotheses associated with the first candidate cell and the second candidate cell may be used in a time division multiplexing (TDM) manner.

[0111] In some example embodiments, after transmitting the PRACH, a QCL hypothesis associated with a first candidate cell may be used for a defined or configured time window to monitor RAR, and another QCL hypothesis associated with a second candidate cell may be used after the defined or configured time window.

[0112] In some example embodiments, the QCL hypothesis associated with the first candidate cell may be used after the last symbol of the PRACH opportunity corresponding to the transmission of the PRACH.

[0113] In some example embodiments, the terminal device 110 may also switch back to the QCL assumption associated with the serving cell after receiving a RAR from at least one candidate cell, or expiry of a window for monitoring the RAR.

[0114] In some example embodiments, a QCL assumption associated with a candidate cell of one or more candidate cells may correspond to a downlink reference signal associated with the candidate cell, and the QCL assumption may be set to one of the QCL types including "Type A", "Type B", "Type C", or "Type D".

[0115] The above reference Figures 2 to 3 All operations and features described are also applicable to the method 400 and have similar effects. For the purpose of simplicity, details will be omitted.

[0116] Figure 5 FIG. 5 is a flow chart illustrating an example method 500 implemented at a network device according to some example embodiments of the present disclosure. For discussion purposes, reference will be made to FIG. Figure 1 Method 500 is described from the perspective of network device 120. It should be understood that although method 500 has been described from the perspective of network device 120, method 500 may be performed by any other network device.

[0117] At 510, the network device 120 obtains a configuration for a quasi co-location (QCL) for one or more candidate cells for the terminal device 110. At 520, the network device 120 sends the configuration of the QCL to the terminal device 110, so that the terminal device 110 can receive a random access response (RAR) from at least one of the one or more candidate cells based on the configuration.

[0118] In some example embodiments, network device 120 may also send an indication to terminal device 110 indicating that terminal device 110 receives a RAR from at least one candidate cell.

[0119] In some example embodiments, a quasi co-location (QCL) configuration may be obtained from one or more candidate cells.

[0120] In some example embodiments, the configuration may configure the terminal device 110 using one or more QCL hypotheses, the one or more QCL hypotheses being used to receive one or more QCL hypotheses of a type 1 physical downlink control channel (PDCCH) common search space (CSS) set containing RARs, and each of the one or more QCL hypotheses may be associated with a candidate cell.

[0121] In some example embodiments, the configuration may configure the terminal device 110 to have one or more Type 1 PDCCH CSS sets, and one or more associated control resource sets (CORESETs), and the one or more associated CORESETs may correspond to one or more QCL hypotheses.

[0122] In some example embodiments, a QCL assumption associated with a candidate cell of one or more candidate cells may correspond to a downlink reference signal associated with the candidate cell, and the QCL assumption may be set to one of the QCL types including "Type A", "Type B", "Type C", or "Type D".

[0123] The above reference Figures 2 to 3 All operations and features described are also applicable to the method 500 and have similar effects. For the purpose of simplicity, details will be omitted.

[0124] Figure 6 FIG. 6 is a flow chart illustrating an example method 600 implemented at a network device according to some other example embodiments of the present disclosure. For discussion purposes, reference will be made to FIG. Figure 1 Method 600 is described from the perspective of network device 120. It should be understood that although method 600 has been described from the perspective of network device 120, method 600 may be performed by any other network device.

[0125] At 610, network device 120 transmits a quasi co-location (QCL) configuration associated with a candidate cell to a serving cell for terminal device 110. At 620, network device 120 receives a physical random access channel (PRACH) from terminal device 110 based on the QCL configuration. At 630, network device 120 transmits a random access response (RAR) to terminal device 110.

[0126] In some example embodiments, the PRACH may be received based on a QCL assumption associated with the candidate cell.

[0127] In some example embodiments, the RAR may be sent after a PRACH opportunity corresponding to a transmission of the PRACH.

[0128] In some example embodiments, another RAR may also be sent from another candidate cell based on a QCL hypothesis associated with the other candidate cell.

[0129] In some example embodiments, the RAR and the further RAR may be transmitted from the candidate cell and the further candidate cell in a time division multiplexing (TDM) manner.

[0130] In some example embodiments, a QCL assumption associated with a candidate cell of one or more candidate cells may correspond to a downlink reference signal associated with the candidate cell, and the QCL assumption may be set to one of the QCL types including "Type A", "Type B", "Type C", or "Type D".

[0131] The above reference Figures 2 to 3 All operations and features described are also applicable to method 600 and have similar effects. For the purpose of simplicity, details will be omitted.

[0132] In some example embodiments, an apparatus capable of performing any operation of method 400 (e.g., terminal device 110) may include a component for performing each step of method 400. The component may be implemented in any suitable form. For example, the component may be implemented in a circuit system or a software module.

[0133] In some example embodiments, the apparatus may include: a component for receiving, from a serving cell for the terminal device, a configuration of a quasi co-location (QCL) for one or more candidate cells for the terminal device; a component for sending a physical random access channel (PRACH) to at least one candidate cell among the one or more candidate cells; and a component for monitoring a random access response (RAR) from at least one candidate cell based on the configuration of the QCL for the at least one candidate cell.

[0134] In some example embodiments, the terminal device may further comprise means for receiving an indication from a serving cell indicating that the terminal device receives a RAR from at least one candidate cell.

[0135] In some example embodiments, the terminal device may further comprise means for receiving a RAR from at least one candidate cell.

[0136] In some example embodiments, the configuration may configure the terminal device using one or more QCL assumptions for receiving a type 1 physical downlink control channel (PDCCH) common search space (CSS) set containing RARs, and each of the one or more QCL assumptions may be associated with a candidate cell.

[0137] In some example embodiments, a terminal device may be configured with one or more Type 1 PDCCH CSS sets, and one or more associated control resource sets (CORESETs), and the one or more associated CORESETs may respectively correspond to one or more QCL hypotheses.

[0138] In some example embodiments, a QCL hypothesis associated with at least one candidate cell in the configuration may be used to monitor RAR.

[0139] In some example embodiments, the QCL assumption may be used to monitor the RAR after the last symbol of a PRACH opportunity corresponding to a transmission of the PRACH.

[0140] In some example embodiments, the at least one candidate cell may include at least a first candidate cell and a second candidate cell, and the terminal device may further include: means for using QCL hypotheses associated with the first candidate cell and the second candidate cell for monitoring RAR after transmitting the PRACH.

[0141] In some example embodiments, the QCL hypotheses associated with the first candidate cell and the second candidate cell may be used in a time division multiplexing (TDM) manner.

[0142] In some example embodiments, after transmitting the PRACH, a QCL hypothesis associated with a first candidate cell may be used for a defined or configured time window to monitor RAR, and another QCL hypothesis associated with a second candidate cell may be used after the defined or configured time window.

[0143] In some example embodiments, the QCL hypothesis associated with the first candidate cell may be used after the last symbol of the PRACH opportunity corresponding to the transmission of the PRACH.

[0144] In some example embodiments, the terminal device may further comprise means for switching to a QCL hypothesis associated with the serving cell following receipt of a RAR from at least one candidate cell, or expiry of a window for monitoring the RAR.

[0145] In some example embodiments, a QCL assumption associated with a candidate cell of one or more candidate cells may correspond to a downlink reference signal associated with the candidate cell, and the QCL assumption may be set to one of the QCL types including "Type A", "Type B", "Type C", or "Type D".

[0146] In some example embodiments, an example method implemented at a terminal device is provided. The method may include: receiving an indication from a network device (e.g., from a serving cell) indicating that the terminal device receives a RAR from at least one candidate cell. The method also includes: a component for monitoring the RAR from at least one candidate based on the indication. It should be noted that the apparatus may be used with reference to Figures 2 to 4 The solutions described can be used separately or in combination.

[0147] In some example embodiments, an example method implemented at a network device is provided. The method may include: sending an indication indicating that a terminal device receives a RAR from at least one candidate cell. It should be noted that the apparatus may be similar to the method described in the referenced embodiment. Figures 2 to 3 and Figures 4 and 5 The solutions described can be used separately or in combination.

[0148] In some example embodiments, an apparatus capable of performing any of the methods 500 (e.g., network device 120) may include components for performing the various steps of the method 500. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0149] In some example embodiments, the apparatus may further include: a component for obtaining a configuration of a quasi co-location (QCL) for one or more candidate cells for a terminal device; and a component for sending the configuration of the QCL to the terminal device so that the terminal device can receive a random access response (RAR) from at least one of the one or more candidate cells based on the configuration.

[0150] In some example embodiments, the network device may further comprise means for sending an indication to the terminal device indicating that the terminal device receives a RAR from at least one candidate cell.

[0151] In some example embodiments, a quasi co-location (QCL) configuration may be obtained from one or more candidate cells.

[0152] In some example embodiments, the configuration may configure the terminal device using one or more QCL assumptions for receiving a type 1 physical downlink control channel (PDCCH) common search space (CSS) set containing a RAR, and each of the one or more QCL assumptions may be associated with a candidate cell.

[0153] In some example embodiments, the configuration may configure the terminal device to have one or more Type 1 PDCCH CSS sets, and one or more associated control resource sets (CORESETs), and the one or more associated CORESETs may correspond to one or more QCL hypotheses.

[0154] In some example embodiments, a QCL assumption associated with a candidate cell of one or more candidate cells may correspond to a downlink reference signal associated with the candidate cell, and the QCL assumption may be set to one of the QCL types including "Type A", "Type B", "Type C", or "Type D".

[0155] In some example embodiments, an apparatus capable of performing any of the methods 600 (e.g., network device 120) may include components for performing the various steps of the method 600. The components may be implemented in any suitable form. For example, the components may be implemented in a circuit system or a software module.

[0156] In some example embodiments, the apparatus may further include: a component for sending a quasi-co-location (QCL) configuration associated with a candidate cell to a serving cell for a terminal device; a component for receiving a physical random access channel PRACH from the terminal device based on the QCL configuration; and a component for sending a random access response RAR to the terminal device.

[0157] In some example embodiments, the PRACH may be received based on a QCL assumption associated with the candidate cell.

[0158] In some example embodiments, the RAR may be sent after a PRACH opportunity corresponding to a transmission of the PRACH.

[0159] In some example embodiments, another RAR may also be sent from another candidate cell based on a QCL hypothesis associated with the other candidate cell.

[0160] In some example embodiments, the RAR and the further RAR may be transmitted from the candidate cell and the further candidate cell in a time division multiplexing (TDM) manner.

[0161] In some example embodiments, a QCL assumption associated with a candidate cell of one or more candidate cells may correspond to a downlink reference signal associated with the candidate cell, and the QCL assumption may be set to one of the QCL types including "Type A", "Type B", "Type C", or "Type D".

[0162] In some example embodiments, an apparatus implemented at a terminal device is provided. The apparatus may include: a component for receiving an indication from a network device (e.g., from a serving cell) indicating that the terminal device receives a RAR from at least one candidate cell. The apparatus also includes: a component for monitoring the RAR from at least one candidate based on the indication. It should be noted that the method may be similar to the method described with reference to Figures 2 to 4 The solutions described can be used separately or in combination.

[0163] In some example embodiments, an apparatus implemented at a network device is provided. The method may include: sending an indication indicating that a terminal device receives a RAR from at least one candidate cell. It should be noted that the apparatus may be used with reference to Figures 2 to 3 and Figures 4 and 5 The solutions described can be used separately or in combination.

[0164] Figure 7 7 is a simplified block diagram of a device 700 suitable for implementing an embodiment of the present disclosure. The device 700 may be provided to implement a communication device, such as Figure 1 The terminal device 70 or network device 120 is shown. As shown, the device 700 includes one or more processors 710, one or more memories 720 can be coupled to the processor 710, and one or more transmitters and / or receivers (TX / RX) 740 can be coupled to the processor 710.

[0165] The TX / RX 740 is used for bidirectional communication. The TX / RX 740 has at least one antenna to facilitate communication. The communication interface may represent any interface required to communicate with other network elements. The communication interface may be a hardware or software based interface. For example, the communication interface may be one or more transceivers. The one or more transceivers may be coupled to one or more antennas or antenna ports to wirelessly transmit and / or receive communication signals. The antennas or antenna ports may be of the same or different types. The antennas or antenna ports may be located at different locations on the device. The one or more transceivers allow the device to communicate with other wired and / or wireless devices. The transceiver may support one or more radio technologies. For example, the one or more transceivers may include a cellular subsystem, a WLAN subsystem, and / or a Bluetooth subsystem. TM Subsystem. One or more transceivers may include a processor, controller, radio, jack, plug, cache, and other circuitry to form one or more communication channels to one or more radio frequency units.

[0166] Processor 710 can be of any type suitable for the local technology network and, as non-limiting examples, can include one or more of the following: 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. Device 700 can have multiple processors, such as application-specific integrated circuit chips, which are time-slave to the clock of a synchronized master processor.

[0167] The memory 720 may include one or more non-volatile memories and one or more volatile memories. Examples of non-volatile memories include, but are not limited to, read-only memory (ROM) 724, electrically programmable read-only memory (EPROM), flash memory, hard disks, compact disks (CDs), digital video disks (DVDs), and other magnetic and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 722 and other volatile memories that will not persist during a power outage.

[0168] The computer program 730 includes computer executable instructions that are executed by the associated processor 710. The program 730 may be stored in the ROM 724. The processor 710 may perform any suitable actions and processes by loading the program 730 into the RAM 722.

[0169] The embodiments of the present disclosure can be implemented with the help of a program so that the device 700 can execute the reference Figures 2 to 3 The embodiments of the present disclosure may also be implemented by hardware or a combination of software and hardware.

[0170] In some example embodiments, the program 730 may be tangibly included in a computer-readable medium, which may be included in the device 700 (e.g., the memory 720) or other storage device accessible by the device 700. The device 700 may load the program 730 from the computer-readable medium to the RAM 722 for execution. The computer-readable medium may include any type of tangible non-volatile storage, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc.

[0171] Figure 8 An example of a computer readable medium 800 is shown in the form of a CD or DVD. The computer readable medium has a program 730 stored thereon.

[0172] In general, various embodiments of the present disclosure may be implemented in hardware or dedicated circuits, software, logic, or any combination thereof. Some aspects may be implemented in hardware, while other aspects may be implemented in firmware or software that may be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of the present disclosure are shown and described as block diagrams, flow charts, or using some other graphical representation, it should be understood that, as non-limiting examples, the blocks, devices, systems, techniques, or methods described herein may be implemented in hardware, software, firmware, dedicated circuits or logic, general-purpose hardware or a controller or other computing device, or some combination thereof.

[0173] The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer executable instructions, such as those included in a program module, that are executed in a device on a target real or virtual processor to perform the above-referenced Figures 4 to 6 Methods 400, 500, or 600 are described. Typically, program modules include routines, programs, libraries, objects, classes, components, data structures, etc. that perform specific tasks or implement specific abstract data types. The functionality of program modules can be combined or split between program modules as needed in various embodiments. Machine-executable instructions for program modules can be executed in local or distributed devices. In distributed devices, program modules can be located in both local and remote storage media.

[0174] The program code for performing the disclosed method can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing apparatus so that the program code, when executed by the processor or controller, causes the function / operation specified in the flow chart and / or block diagram to be realized. The program code can be executed completely on the machine, partially on the machine, as an independent software package, partially on the machine, partially on a remote machine, or completely on a remote machine or server.

[0175] In the context of the present disclosure, computer program codes or related data may be carried by any suitable carrier to enable a device, apparatus or processor to perform various processes and operations as described above. Examples of carriers include signals, computer-readable media, etc.

[0176] Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable media can include, but are not limited to, electronic, magnetic, optical, electromagnetic, infrared or semiconductor systems, devices or equipment, any appropriate combination of the foregoing. More specific examples of computer-readable storage media will include electrical connections with one or more wires, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, portable compact disc read-only memories (CD-ROMs), optical storage devices, magnetic storage devices, or any appropriate combination of the foregoing. The term "non-transient" as used herein is a restriction on the medium itself (i.e., tangible, rather than signal), rather than a restriction on data storage persistence (e.g., RAM versus ROM).

[0177] In addition, although operations are described in a particular order, this should not be understood as requiring that such operations be performed in the particular order or sequence shown, or that all of the operations shown be performed to achieve the desired result. In some cases, multitasking and parallel processing can be advantageous. Similarly, although the above discussion includes several specific implementation details, these details should not be interpreted as limiting the scope of this disclosure, but rather as descriptions of features specific to a particular embodiment. Certain features described in the context of a separate embodiment may also be implemented in combination in a single embodiment. On the contrary, the various features described in the context of a single embodiment may also be implemented in multiple embodiments individually or in any suitable subcombination.

[0178] Although the disclosure has been described in language specific to structural features and / or methodological acts, it should be understood that the 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

1. A terminal device, comprising: one or more transceivers; as well as one or more processors coupled to the one or more transceivers, wherein the one or more transceivers are configured, together with the one or more processors, to cause the terminal device to: receiving, from a serving cell for the terminal device, a configuration of a quasi-co-located QCL for one or more candidate cells for the terminal device; Sending a physical random access channel (PRACH) to at least one candidate cell among the one or more candidate cells; as well as Based on the configuration of the QCL for the at least one candidate cell, a random access response (RAR) from the at least one candidate cell is monitored.

2. The terminal device according to claim 1, wherein the terminal device is further configured to: An indication is received from the serving cell indicating that the terminal device receives the RAR from the at least one candidate cell.

3. The terminal device according to claim 1 or 2, wherein the terminal device is further configured to: The RAR is received from the at least one candidate cell.

4. A terminal device according to any one of claims 1 to 3, wherein the configuration utilizes one or more QCL assumptions to configure the terminal device, the one or more QCL assumptions being used to receive a type 1 physical downlink control channel PDCCH common search space CSS set containing the RAR, and wherein each of the one or more QCL assumptions is associated with a candidate cell.

5. A terminal device according to any one of claims 1 to 4, wherein the terminal device is configured with one or more type 1 PDCCH CSS sets and one or more associated control resource sets CORESETs, and wherein the one or more associated CORESETs correspond to one or more QCL assumptions respectively. 6 . The terminal device according to claim 4 , wherein the QCL hypothesis associated with the at least one candidate cell in the configuration is used to monitor the RAR.

7. The terminal device of claim 6, wherein the QCL hypothesis is used to monitor the RAR after a last symbol of a PRACH opportunity corresponding to the transmission of the PRACH.

8. The terminal device according to any one of claims 1 to 7, wherein the at least one candidate cell comprises at least a first candidate cell and a second candidate cell, and the terminal device is further configured to: After sending the PRACH, the QCL hypotheses associated with the first candidate cell and the second candidate cell are used for monitoring the RAR. 9 . The terminal device according to claim 8 , wherein the QCL assumptions associated with the first candidate cell and the second candidate cell are used in a time division multiplexing (TDM) manner.

10. A terminal device according to claim 8 or 9, wherein after sending the PRACH, the QCL hypothesis associated with the first candidate cell is used for a defined or configured time window to monitor the RAR, and another QCL hypothesis associated with the second candidate cell is used after the defined or configured time window.

11. The terminal device according to any one of claims 8 to 10, wherein the QCL hypothesis associated with the first candidate cell is used after a last symbol of a PRACH opportunity corresponding to the transmission of the PRACH.

12. The terminal device according to any one of claims 1 to 11, wherein the terminal device is further configured to: After receiving the RAR from the at least one candidate cell or after expiration of a window for monitoring the RAR, switching back to the QCL hypothesis associated with the serving cell.

13. The terminal device according to any one of claims 1 to 12, wherein: A QCL hypothesis associated with a candidate cell of the one or more candidate cells corresponds to a downlink reference signal associated with the candidate cell, and The QCL assumption is set to one of the QCL types including "Type A", "Type B", "Type C" or "Type D".

14. A network device comprising: one or more transceivers; as well as one or more processors coupled to the one or more transceivers, wherein the one or more transceivers are configured, together with the one or more processors, to cause the network device to act as a serving cell for a terminal device: Obtaining a configuration of a quasi-co-located QCL for one or more candidate cells for the terminal device; as well as The configuration of the QCL is sent to the terminal device, so that the terminal device can receive a random access response RAR from at least one candidate cell among the one or more candidate cells based on the configuration.

15. The network device of claim 14, wherein the network device is further configured to: An indication is sent to the terminal device indicating that the terminal device receives the RAR from the at least one candidate cell.

16. The network device according to claim 14 or 15, wherein the configuration of the quasi co-located QCL is obtained from the one or more candidate cells.

17. A network device according to any one of claims 14 to 16, wherein the configuration utilizes one or more QCL assumptions to configure the terminal device, the one or more QCL assumptions being used to receive a type 1 physical downlink control channel PDCCH common search space CSS set containing the RAR, and wherein each of the one or more QCL assumptions is associated with a candidate cell.

18. A network device according to any one of claims 14 to 17, wherein the configuration configures the terminal device to have one or more type 1 PDCCH CSS sets, and one or more associated control resource sets CORESETs, and wherein the one or more associated CORESETs correspond to one or more QCL assumptions.

19. The network device according to any one of claims 14 to 18, wherein: A QCL hypothesis associated with a candidate cell of the one or more candidate cells corresponds to a downlink reference signal associated with the candidate cell, and The QCL assumption is set to one of the QCL types including "Type A", "Type B", "Type C" or "Type D".

20. A network device comprising: one or more transceivers; as well as one or more processors coupled to the one or more transceivers, wherein the one or more transceivers are configured, with the one or more processors, to cause the network device acting as a candidate cell for a terminal device to: Sending a configuration of a quasi-co-located QCL associated with the candidate cell to a serving cell for the terminal device; Based on the configuration of the QCL, receiving a physical random access channel PRACH from the terminal device; as well as Send a random access response RAR to the terminal device.

21. The network device of claim 20, wherein the PRACH is received based on a QCL assumption associated with the candidate cell.

22. The network device according to claim 20 or 21, wherein the RAR is sent after a PRACH opportunity corresponding to the transmission of the PRACH.

23. The network device according to any one of claims 20 to 22, wherein another RAR is further sent from another candidate cell based on a QCL hypothesis associated with the another candidate cell. 24 . The network device according to claim 23 , wherein the RAR and the another RAR are transmitted from the candidate cell and the another candidate cell in a time division multiplexing (TDM) manner.

25. The network device according to any one of claims 20 to 24, wherein: A QCL hypothesis associated with a candidate cell of the one or more candidate cells corresponds to a downlink reference signal associated with the candidate cell, and The QCL assumption is set to one of the QCL types including "Type A", "Type B", "Type C" or "Type D".

26. A method at a terminal device, comprising: receiving, from a serving cell for the terminal device, a configuration of a quasi-co-located QCL for one or more candidate cells for the terminal device; Sending a physical random access channel (PRACH) to at least one candidate cell among the one or more candidate cells; as well as Based on the configuration of the QCL for the at least one candidate cell, a random access response (RAR) from the at least one candidate cell is monitored.

27. A method at a network device acting as a serving cell for a terminal device, comprising: Obtaining a configuration of a quasi-co-located QCL for one or more candidate cells for the terminal device; as well as The configuration of the QCL is sent to the terminal device, so that the terminal device can receive a random access response RAR from at least one candidate cell among the one or more candidate cells based on the configuration.

28. A method at a network device acting as a candidate cell for a terminal device, comprising: Sending a configuration of a quasi-co-located QCL associated with the candidate cell to a serving cell for the terminal device; Based on the configuration of the QCL, receiving a physical random access channel PRACH from the terminal device; as well as Send a random access response RAR to the terminal device.

29. A terminal device, comprising: means for receiving, from a serving cell for the terminal device, a configuration for a quasi-co-located QCL for one or more candidate cells for the terminal device; means for sending a physical random access channel (PRACH) to at least one candidate cell among the one or more candidate cells; as well as means for monitoring a random access response (RAR) from the at least one candidate cell based on the configuration of the QCL for the at least one candidate cell.

30. An apparatus of a network device acting as a serving cell for a terminal device, comprising: means for obtaining a configuration of a quasi co-located QCL for one or more candidate cells for the terminal device; as well as means for sending the configuration of the QCL to the terminal device so that the terminal device can receive a random access response RAR from at least one candidate cell of the one or more candidate cells based on the configuration.

31. An apparatus for a network device acting as a candidate cell for a terminal device, comprising: means for sending a configuration of a quasi co-located QCL associated with the candidate cell to a serving cell for the terminal device; means for receiving a physical random access channel (PRACH) from said terminal device based on said configuration of QCL; as well as A component for sending a random access response RAR to the terminal device.

32. A terminal device comprising: at least one processor; as well as at least one memory, the at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the terminal device to: receiving, from a serving cell for the terminal device, a configuration of a quasi-co-located QCL for one or more candidate cells for the terminal device; Sending a physical random access channel (PRACH) to at least one candidate cell among the one or more candidate cells; as well as Based on the configuration of the QCL for the at least one candidate cell, a random access response (RAR) from the at least one candidate cell is monitored.

33. A network device acting as a serving cell for a terminal device, comprising: at least one processor; as well as at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the network device to: Obtaining a configuration of a quasi-co-located QCL for one or more candidate cells for the terminal device; as well as The configuration of the QCL is sent to the terminal device, so that the terminal device can receive a random access response RAR from at least one candidate cell among the one or more candidate cells based on the configuration.

34. A network device acting as a candidate cell for a terminal device, comprising: at least one processor; as well as at least one memory including computer program code, wherein the at least one memory and the computer program code are configured to, together with the at least one processor, cause the network device to: sending a configuration of a quasi co-located QCL associated with the candidate cell to a serving cell for the terminal device; and Based on the configuration of the QCL, receiving a physical random access channel PRACH from the terminal device; Send a random access response RAR to the terminal device.

35. A non-transitory computer-readable medium comprising program instructions for causing an apparatus to at least perform the method according to any one of claims 26 to 28.

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