Multi-link based communications

Abstract

Example embodiments of the present disclosure relate to, apparatuses methods and computer readable medium for multi-link based communications. In a method, first apparatus receives, from a second apparatus, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell. The second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell. The first apparatus performs communications with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

Description

[0001] MULTI-LINK BASED COMMUNICATIONS

[0002] FIELDS

[0003] [1] Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to apparatuses, methods and computer readable medium for multi-link based communications.

[0004] BACKGROUND

[0005] [2] Transferring an ongoing connection from one network to another is commonly called a handover. In traditional handovers, such as a basic handover (BHO), a conditional handover (CHO) and lower layer triggered mobility (LTM), the cell-radio network temporary identifier (C-RNTI) is changed in the random access channel (RACH) procedure or in the RACH-less handover by radio resource control (RRC)-reconfiguration when a user equipment (UE) is accessing a new cell. In this process, privacy of the UE needs to be maintained while changing cells inside of the radio access network (RAN).

[0006] SUMMARY

[0007] [3] 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 first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, where the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and perform communications with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

[0008] [4] 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 first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, where the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and transmit, to the first apparatus, an indication that the first apparatus is to communicate with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

[0009] [5] In a third aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a second apparatus, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, where the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and performing communications with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

[0010] [6] In a fourth aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a first apparatus, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, where the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and transmitting, to the first apparatus, an indication that the first apparatus is to communicate with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

[0011] [7] 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 first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, where the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and means for performing communications with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

[0012] [8] 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 first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, where the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and means for transmitting, to the first apparatus, an indication that the first apparatus is to communicate with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

[0013] [9] 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.

[0014]

[0010] 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.

[0015]

[0011] 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.

[0016] BRIEF DESCRIPTION OF THE DRAWINGS

[0017]

[0012] Some example embodiments will now be described with reference to the accompanying drawings, where:

[0018]

[0013] FIG. 1 illustrates a signaling diagram 100 for ICBM within intra-DU in accordance with some example embodiments of the present disclosure;

[0019]

[0014] FIG. 2 illustrates options for multi-DCI multi-TRP in accordance with some example embodiments of the present disclosure;

[0020]

[0015] FIG. 3 A illustrates an example ICBM usage for links of two cells in accordance with some example embodiments of the present disclosure;

[0021]

[0016] FIG. 3B illustrates a further example ICBM usage for links of two cells in accordance with some example embodiments of the present disclosure;

[0022]

[0017] FIG. 4 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

[0023]

[0018] FIG. 5 illustrates a signaling diagram for communication in accordance with some example embodiments of the present disclosure;

[0024]

[0019] FIG. 6 illustrates a flowchart of an example signaling diagram of C-RNTI switching in accordance with some example embodiments of the present disclosure;

[0025]

[0020] FIG. 7 illustrates a flowchart of an example method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0026]

[0021] FIG. 8 shows a flowchart of an example method implemented at a second apparatus in accordance with some example embodiments of the present disclosure;

[0027]

[0022] FIG. 9 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0028]

[0023] FIG. 10 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.

[0029]

[0024] Throughout the drawings, the same or similar reference numerals represent the same or similar element.

[0030] DETAILED DESCRIPTION

[0031]

[0025] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

[0032]

[0026] 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.

[0033]

[0027] 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.

[0034]

[0028] It shall be understood that although the terms “first,” “second,” ..., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0035]

[0029] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0036]

[0030] 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.

[0037]

[0031] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprise”, “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.

[0038]

[0032] As used in this application, the term “circuitry” may refer to one or more or all of the following:

[0039] (a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and

[0040] (b) combinations of hardware circuits and software, such as (as applicable):

[0041] (i) a combination of analog and / or digital hardware circuit(s) with software / firmware and

[0042] (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

[0043] (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.

[0044]

[0033] 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.

[0045]

[0034] 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 will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0046]

[0035] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN) split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

[0047]

[0036] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0048]

[0037] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and / or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted that example embodiments of the present disclosure are equally applicable to other resources in other domains.

[0049]

[0038] As used herein, Inter-cell beam management (ICBM) is a feature based on the unified transmission configuration indicator (TCI) framework, and it refers to borrowing of a neighbor’s beam for uplink and downlink transmissions. ICBM allows a serving cell to borrow a beam of a neighbor cell for beam management, effectively extending coverage of the serving cell. ICBM makes use of the unified TCI state framework. In the Release- 17 (Rel-17) unified TCI state framework, the TCI state may be indicated in the DCI, and a TCI state change may apply to both uplink and downlink beams. In addition, the user specific search space (USS) may remain, and the user-specific physical downlink control channel (PDCCH) may be transmitted with the same configuration and scrambling on the beam of the neighbor cell.

[0050]

[0039] RRC configuration steps for ICBM may include configuring the UE with TCI states by the network (for example, a centralized unit) for both source and neighbor cell, beam switching using Medium Access Control (MAC) and physical layer (PHY) signaling, activating and indicating TCI states with MAC Control Element (CE), and indicating TCI states with DCI.

[0051]

[0040] In some scenarios, ICBM may be performed in an intra-distributed unit (DU) case. FIG. 1 illustrates a signaling diagram 100 for ICBM within intra-DU in accordance with some example embodiments of the present disclosure. As shown in FIG. 1, in this CU-DU split case, the signaling diagram 100 involves a UE 102, a DU 104 and a CU 106.

[0052]

[0041] At 110, the CU 106 transmits an RRC reconfiguration including a synchronization signal block (SSB) for cell 2 or a channel state information reference signal (CSI-RS) for cell 2 to the UE 102. Normal layer 1 (LI) measurement reports including neighbor cells may be configured, which could be started, for example, by a layer 3 (L3) A3 trigger.

[0053]

[0042] At 112, the UE 102 transmits an LI report to the DU 104. The LI report may indicate that the beam of cell 2 is increasing in strength. At 114, the DU 104 determines to add ICBM. The serving DU 104 may perform access control (AC) with target (for example the same DU with or without RRC signaling).

[0054]

[0043] At 116, the DU 104 initiates a setup of ICBM by requesting the CU 106 to configure the UE 102 for ICBM. In some case, the above signaling with AC and the present signaling may be combined.

[0055]

[0044] At 118, the CU 106 transmits an RRC reconfiguration for adding a TCI state for the beam of cell 2. The UE 102 is configured to enable using cell 2 while maintaining serving cell 1. The CU 106 configures unified-TCI states to the UE 102, which also comprise the beam of cell 2. If Bandwidth Parts (BWPs) for the cell 1 and cell 2 are the same, then the beam of cell 2 is an SSB. In an example, the beam of cell 2 may be CSI-RS which may be agreed during the ICBM setup. In addition, data path of the beam of cell 2 may be via the serving cell.

[0056]

[0045] At 120, the DU 104, for example, the serving cell 1, activates TCI states, and activates the beam of cell 2. The beam of cell 1 may be indicated. At 122, when the TCI state of the UE 102 points to cell 2, the UE 102 may listen to the PDCCH on the USS on the beam of cell 2 if the beam of cell 2 is indicated.

[0057]

[0046] For ICBM, the DCI is expected to be generated from the serving cell and physical downlink shared channel (PDSCH) allocation is based on available resources of the serving cell. In addition, this PDSCH is occupied at the target cell resources and the target cell cannot schedule on these resources. For intra-DU cases, a common scheduler for all cells may be considered.

[0058]

[0047] As used herein, multi -downlink control information (m-DCI) multi -transmit receive point (m-TRP) techniques refer to enhancements for downlink control information (DCI) transmissions, allowing usage of multiple transmit receive points (TRPs) and / or cells as well as cross-scheduling.

[0059]

[0048] There are several operations are allowed for PDCCH enhancements for m-DCI m- TRP in Rel-17. FIG. 2 illustrates options for multi-DCI multi-TRP in accordance with some example embodiments of the present disclosure. As shown in FIG. 2, DCI 1 202 may be carried in PDCCH 1 204, and a further DCI 2 206 may be carried in PDCCH 2 208. In another option, a single DCI 210 may be carried in both PDCCH 1 204 and PDCCH 2 208.

[0060]

[0049] In m-DCI m-TRP operations, the UE is scheduled by independent TCIs from each TRP. In a single DCI operation, a DCI is repeated or transmitted in a Single Frequency Network (SFN) mode from two TRPs. These operations may be realized by linking search spaces from different Control Resource Sets (CORESETs). Therefore, the UE may monitor different PDCCH. The DCI on the PDCCHs may be transmitted in resource multiplexed manner.

[0061]

[0050] Further, the DCI transmitted on one beam may schedule a PDSCH on another beam with higher layer configuration linking search spaces of different CORESETs and DCI indications for beam usage. In addition, m-DCI m-TRP may support uplink transmissions for links with different timing advance (TA) belonging to different cells.

[0062]

[0051] As mentioned, m-DCI m-TRP and ICBM may have parts in common, but these features may not deal with mobility, such as changing serving cells. As used herein, LTM is a mobility feature using beam level measurements. In LTM, the network prepares a set of candidate cells on the RRC level. The UE then is configured with LI measurement reporting. Those LI measurement reports are not RRC messages but are available on the MAC level. For a CU-DU split case, this allows the DU to monitor the link quality and quickly instruct the UE via MAC-CE signaling to switch cells to one of the prepared targets.

[0063]

[0052] In an example, in LTM, for a CU-DU split intra-CU admission control and preparation of cells may be performed. Future versions of the standard cells participating in LTM may be extended for target cells comprising inter-DU cells or inter-gNB cells. RRC configuration of prepared cells may be transmitted from the network to the UE, and then LI measurements may be transmitted from the UE to the network. MAC-CE signaling may be transmitted from the network to the UE for cell switch. In response to the reception of a cell switch command, the UE may activate the previously configured RRC reconfiguration, and perform the reconfiguration. The RRC reconfiguration may comprise physical channel settings of the target cell and a protocol stack configuration. In this scenario, channels may be set up as new channels and the MAC stack has the option of not to be reset.

[0064]

[0053] Comparing LTM and ICBM, the difference between LTM and ICBM is that in LTM, an RRC reconfiguration is carried out to switch to the beam of the target cell, and specific settings of the target cell are configured for the target beam, according to normal handover procedures. In ICBM, however, the beam of the neighbor cell uses physical layer parameters of the source cells, and no RRC reconfiguration is carried out when beams are switched.

[0065]

[0054] For the cell-radio network temporary identifier (C-RNTI), it is a 16-bit long number that is used for scrambling the cyclic redundancy check (CRC) of a DCI. A UE that has been configured with the C-RNTI and has been configured to receive the DCI is able to descramble and decode the DCI. This allows the network configuring search spaces which are overlapped but delivering DCIs to specific UEs. The C-RNTI may be also used in uplink to differentiate an uplink answer of the UE to a Random Access Response (RAR) uplink grant from other UEs.

[0066]

[0055] In a connected mode, the C-RNTI may further serve for initialization of the scrambling of data, together with the physical cell identifier (PCI) of the cell as following: c init = fct (n RNTI, n_PCI)

[0067]

[0056] This type of initialization may be defined for the PDCCH, PDSCH, PUSCH as well as PUCCH (for example, format 2).

[0068]

[0057] C-RNTI space across cells should be distinct. The inventors note that C-RNTI is visible on the air interface. For privacy reasons, the UE movement should not be trackable across cells via the air-interface. Therefore, a UE should not continuously use the same C-RNTI but the C-RNTI should be changed for every cell. Segmentation of the C-RNTI space to cells is managed by higher layer functions of the network, and allocation of C- RNTI to UEs in a cell is signaled for instance during the initial access of the RACH or during a handover via RRC reconfiguration. In addition, dataScramblingldentityP J CH Information Element (IE) and dalaScramblingldenlilyPD C IE may be configured to initialize the scrambling.

[0069]

[0058] For Master Cell Group (MCG)-Secondary Cell Group (SCG) operations, a UE may be set up with dual links to two separate cell groups which are referred to as the MCG and the SCG. The MCG and SCG may be each their own gNB, and the links to the Special Cells (SpCells) of MCG and SCG may be set up with their own C-RNTI. Furthermore, the MCG-SCG requires two separate receive / transmit chains. MCG-SCG operation does not comprise switching UE beams between MCG and SCG cells via DCI commands (in difference to ICBM) and does not comprise cell switching or HO via MAC CEs (in difference to LTM).

[0059] As mentioned, the C-RNTI is changed in a traditional handover in the RACH procedure or in the RACH-less handover by RRC-reconfiguration when a UE is accessing a new cell. Regarding this, a stepwise mobility method may be proposed, in which the physical link to the target cell 2 is established using ICBM or m-DCI techniques before the handover. The ICBM / m-DCI m-TRP features are designed for coverage extension and robustness of PDCCH transmissions, for example. Hence, the transmissions on a beam of a neighbouring cell may use the C-RNTI of the serving cell. FIG. 3A illustrates an example ICBM usage for links of two cells in accordance with some example embodiments of the present disclosure. As shown in FIG. 3 A, a physical link 316 has been established between a UE 310 and a cell 1 312 before a handover from the source cell 1 312 to a target cell 2 314. The UE 310 has been configured with a C-RNTI 1 320 of the cell 1 312. When the UE 310 accesses the cell 2, a physical link 318 between the UE 310 and the target cell 2 may be established. The transmissions on a beam of the target cell 2 may also use the C-RNTI 1 320 of the cell 1 312.

[0070]

[0060] According to another method , given that two physical links to two cells are established using ICBM / m-DCI m-TRP, it seems however possible to use those physical links also for mobility. FIG. 3B illustrates a further example ICBM usage for links of two cells in accordance with some example embodiments of the present disclosure. As shown in FIG. 3B, a physical link 316 has been established between the UE 310 and the cell 1 312 before a handover from the source cell 1 312 to the target cell 2 314. The UE 310 has been configured with a C-RNTI 1 320 of the cell 1 312. While the UE 310 moves from the source cell 1 to the target cell 2, an ICBM-based mobility would mean that the network shall maintain its beam that has already been established and eventually perform a role change, making the cell 2 314 the serving cell. In this way, the cell 2 cannot use C-RNTI 1 312 permanently but should be given a further C-RNTI by the cell 2 314. For example, eventually C-RNTI 1 320 may no longer be used in the cell 2 314, but a new C-RNTI 2 should be given to the UE 310.

[0071]

[0061] A problem with the mentioned stepwise mobility method is in the usage of C-RNTI. When the UE has moved into the coverage of cell 2, it should adopt a C-RNTI unique to the cell 2 considering the privacy of the UE, and should release its previous C-RNTI to avoid having potentially multiple UEs with the same C-RNTI in the same cell (keeping cells’ C-RNTI space separate). That is, to leverage the dual links provided by ICBM or m-DCI m-TRP for mobility, ICBM or m-DCI m-TRP cannot be used without modifications.

[0072]

[0062] Therefore, a new solution is needed to ensure the privacy of a UE, that is, the nontrackability of the UE should be realized via its C-RNTI across cells, as well as cell-level reuse of the C-RNTI space.

[0073]

[0063] Example embodiments of the present disclosure propose a scheme of multi-link (for example, ICBM or m-DCI m-TRP) based communications. With this scheme, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell is transmitted from a second apparatus (for example, a network device) to a first apparatus (for example, a terminal device). Then, the second apparatus transmits an indication that the first apparatus is to communicate with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier. The first apparatus performs communications with the first cell using the first identifier and with the second cell using the second identifier. The first identifier and the second identifier are included in the first TCI state information element (IE) and the second TCI state IE respectively.

[0074]

[0064] In this way, physical links between the first apparatus and the second apparatus do not require reconfiguration when the first apparatus is out of coverage of the former serving cell (for example, the first cell) and a new cell (for example, the second cell) becomes the serving cell.

[0075]

[0065] Example embodiments will be discussed in detailed below with reference to the accompanying figures. FIG. 4 illustrates an example communication environment 400 in which example embodiments of the present disclosure can be implemented.

[0076]

[0066] The communication environment 400 comprises a first apparatus 410 and a second apparatus 420. In some example embodiments, the first apparatus 410 may operate as a terminal device, for example, a UE. The apparatus 420 may operate as a network device, for example, a gNB.

[0077]

[0067] It is to be understood that the number and types of apparatuses are shown in FIG. 4 for the purpose of illustration without suggesting any limitation. For example, the communication environment 400 may include any suitable number of first apparatuses and second apparatuses.

[0078]

[0068] In some example embodiments, a link from the first apparatus 410 to the second apparatus 420 may be referred to as an uplink (UL), and a link from the second apparatus 420 to the first apparatus 410 may be referred to as a downlink (DL). In UL, the second apparatus 420 is a RX device (or a receiver) and the first apparatus 410 is a TX device (or a transmitter). In DL, the second apparatus 420 is a transmitting (TX) device (or a transmitter) and the first apparatus 410 is a receiving (RX) device (or a receiver).

[0079]

[0069] In the following, for the purpose of illustration, some example embodiments are described with the first apparatus 410 operating as a terminal device, and the second apparatus 420 operating as a network device. However, in some example embodiments, operations described with respect to a terminal device may be implemented at a network device or other devices, and operations described with respect to a network device may be implemented at a terminal device or other devices.

[0080]

[0070] The first apparatus 410 and the second apparatus 420 can communicate with each other. Communications in the communication environment 400 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.

[0081]

[0071] Reference is now made to FIG. 5, which illustrates a signaling diagram 500 for communication in accordance with some example embodiments of the present disclosure. As shown in FIG. 5, the signaling diagram 500 involves the first apparatus 410 and the second apparatus 420 in the communication environment 400. The second apparatus 420, for example, may comprise a centralized unit of an access network device, a distributed unit of the access network device, or a C-RNTI management entity of the access network device, or any combinations thereof.

[0082]

[0072] As shown in FIG. 5, the second apparatus 420 transmits (510), to the first apparatus 410, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, and the second identifier is associated with at least one TCI state of the second cell. Although shown as one message in FIG. 5, these may be sent as different messages at the same time or at different times. The first identifier and the second identifier may comprise a first C-RNTI and a second C-RNTI respectively which are unique within corresponding cells. Alternatively, or in addition, the first identifier and the second identifier may comprise a first PCI of the first cell and a second PCI of the second cell. Correspondingly, the first apparatus 410 receives the first identifier and the second identifier from the second apparatus 420.

[0083]

[0073] In an embodiment, the first identifier is included in a first TCI state information element (IE). In an embodiment, the first apparatus is provided with the first identifier (e.g. C-RNTI for the first cell) when the first apparatus connects to the first cell. In an embodiment, at least some (or all) transmissions with the first cell are using the first identifier. In an embodiment, the first identifier is linked to (i.e., associated with) at least one TCI state of the first cell.

[0084]

[0074] In an embodiment, the second identifier is linked to (i.e., associated with) at least one TCI state of the second cell. In an embodiment, the second identifier is received as part of (e.g. is included in) at least one TCI state information element (IE) of / for the second cell. Alternatively, the second cell identifier may be received as a separate message, such as an RRC configuration separate from the TCI state configuration message.

[0085]

[0075] In some example embodiments, the second apparatus 420 may comprise a distributed unit of an access network device. At least one of the first identifier of the first cell or the second identifier of the second cell may be received by the second apparatus 420 from a centralized unit of the access network device or a cell identifier management entity of the access network device.

[0086]

[0076] In some example embodiments, the second apparatus 420 may comprise an access network device serving the first cell. The second identifier of the second cell may be received by the second apparatus 420 from a further access network device serving the second cell.

[0077] The second apparatus 420 transmits (530), to the first apparatus 410, an indication that the first apparatus 410 is to communicate with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier. Correspondingly, the first apparatus 410 receives the indication from the second apparatus 420.

[0087]

[0078] In some example embodiments, this indication may be explicit. For example, the second apparatus 420 may explicitly instruct the first apparatus to communicate with both the first cell and the second cell by sending an explicit indication. For example, the explicit indication may be information indicating that communications with both cells are allowed.

[0088]

[0079] In some other example embodiments, the indication may be implicit. For example, the second apparatus 420 may implicitly instruct the first apparatus 410 to communicate with both the first cell and the second cell by sending both the first identifier and the second identifier to the first apparatus 410 (separately or simultaneously, as explained above). That is, the first apparatus 410 knows that it is allowed to communication with both cells, when the first apparatus 410 is in possession of both identifiers, instead of receiving an explicit indication. In one example, the transmission of the second identifier and the transmission of the indication are thus performed in one step. That is, when the second apparatus 420 transmits (510) the second identifier to the first apparatus 410 (while the first apparatus 410 is already aware of the first identifier), the indication for triggering the communications with both the first cell and the second cell is also implicit.

[0089]

[0080] It is to be understood that the transmission of the first and second identifiers and the transmission of the indication are shown to be separate in FIG. 5 only for the purpose of illustration, without suggesting any limitation. In some example embodiments, the transmission of the first and second identifiers and the transmission of the indication may be integrated into one operation, action or step, for example, in the case that the transmission of the first and second identifiers implicitly indicates the communications with both the first and second cells using the first and second identifiers, as described above.

[0090]

[0081] In some example embodiments, for transmitting (510) at least the second identifier, the second apparatus 420 may transmit, via radio resource control (RRC) signaling, a configuration message indicating configuration of TCI states for one or more cells which includes at least the second cell. The configuration further indicates at least the second identifier. For example, in the example embodiments where a second C-RNTI is used as the second identifier, TCI states for the second cell may have a second C-RNTI attached. The message may also carry the same for the first cell (e.g. TCI states configured for the first cell and / or the first identifier), or there may be a separate message for the TCI states configuration of the first cell (i.e. of the serving cell).

[0091]

[0082] For instance, to carry a C-RNTI, the TCI state IE of the configuration message may be enhanced with a C-RNTI field (‘additional_crnti-rXY') that is set when additionalPCI- rl7 IE is present. The configuration message (partly shown in the below table) may indicate a TCI-State IE to the first apparatus 410. When the IE ‘additionalPCI-rl7' is absent, the indicated TCI-state may be useable for communications with the serving cell (e.g., the cell from which the configuration message was received). When the IE ‘additionalPCI-rl7' is present, the indicated TCI-state may be useable for communications with the cell whose PCI is included in the IE ‘additionalPCI-rl7'.

[0092]

[0083] There may be one C-RNTI per one configured TCI state. In this case the C-RNTIs may be different between different TCI states. Or the C-RNTI may be the same for all indicated TCI states of a particular cell (e.g., the second cell). The configuration message may thus indicate one or more C-RNTIs for one or more TCI states for a particular cell (e.g., the second cell).

[0093]

[0084] The configuration message may comprise the set of C-RNTI(s) for many cells, e.g., for the first and for the second cell. Therefore, this configuration message may provide the first apparatus 410 with a set or list of TCI states, some of which are for communications with the first cell and some of which are for communications with the second cell. The configuration message may further include the second identifier(s) for the set of TCI states of the second cell.

[0094]

[0085] The table below shows how a C-RNTI (or in general any identifier associated to a TCI state) may be indicated in the UE ‘additional crnti-rXY1for the TCI state of the second cell (corresponding to the cell indicated by the IE additionalPCI-rl7). In this way the second identifier is associated or linked with the at least one TCI state of the second cell.

[0095]

[0086] In this way, for example, when the first apparatus 410 is configured with the second identifier (for example, a link-specific second C-RNTI for the second cell) and instructed to use scrambling for the second beam (for example, beams on the second cell), another field with the C-RNTI may be added to the TCI state IE.

[0087] In some other embodiment, other messages or IES may also be used for carrying the identifier of the second cell. In a variant, the first apparatus 410 may be provided with the second C-RNTI for the second cell in a separate message, e.g., in a VarResumeMAC- Input variable:

[0096]

[0088] In an example, whenever a TCI state corresponding to Cellldentity is used, the C- RNTI provided in this “cell-c-RNTI” IE shall be used.

[0089] In one example embodiment of Figure 5, the first apparatus 410 may receive, from the second apparatus, the first identifier for the first cell, and then possibly at a later point in time, receive an indication indicating at least one TCI state for the first beam of the first cell. The first apparatus 410 may further receive at least one TCI state for the second beam of the second cell, and receive the second identifier (e.g., C-RNTI2) which is linked to the TCI state(s) of the second cell. This C-RNTI2 may be included in a configuration message of TCI state(s) for the second beam (possibly communicated using RRC configuration message), or may be provided in a separate (possibly RRC configuration) message.

[0097]

[0090] After the configuration is transmitted via RRC signaling, the second apparatus 420 may transmit, via at least one of a Medium Access Control (MAC) Control Element (CE) or downlink control information (DCI), an indication for activating a TCI state for the second cell. This indication may serve as the indication 530 in Figure 5, for example. For example, the TCI state for the second cell may be activated (as in ICBM) via a MAC CE. A DCI command (network to UE) may be used to instruct the UE (410) to use a certain TCI state among the configured TCI states for that particular cell. Thus, the DCI command may be also used to select the scrambling that will be used for the scrambling for a physical channel between the first apparatus 410 and the second apparatus 420. Therefore, the communication may be controlled by a DCI which indicates to the first apparatus 410 which TCI state and hence which beam and which identifier is to be used in communication with a particular cell or cells.

[0098]

[0091] If the second C-RNTI for the beams for the cell 2 (possible target cell) was provided as mentioned above separately from the TCI state configuration, e.g. possibly in cell-c- RNTI IE, then the second C-RNTI may be used for transmissions with the second cell which are using those TCI states in the UE’s TCI state set, .which include the PCI of the cell 2 in the “additional PCI” IE.

[0099]

[0092] The first apparatus 410 performs (550) communications with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier. .

[0100]

[0093] In some example embodiments, upon receiving the configuration of TCI states and the indication for activating the TCI state for the second cell, the first apparatus 410 may perform the communications after the activation of the TCI state for the second cell. In some example embodiments, the first apparatus 410 may apply resource multiplexing and a single transceiver for the communications. For example, the resource multiplexing may be time domain multiplexing and a single transmitter / receiver may be used.

[0101]

[0094] In some example embodiments, the communication via the first beam may be scrambled using the first identifier and the communication via the second beam may be scrambled using the second identifier. For example, a first C-RNTI and / or a first PCI for the first cell may be used to scramble the communication via the first beam, and the second C-RNTI and / or a second PCI for the second cell may be used to scramble the communication via the second beam. According to the embodiments of the present disclosure, the configuration of scrambling is beam-specific, and linked to a TCI state selection.

[0102]

[0095] In some example embodiments, more than one first identifier is received from the second apparatus 420 which comprises both the first C-RNTI and the first PCI, and more than one second identifier is received from the second apparatus 420 which comprises both the second C-RNTI and the second PCI. In some other example embodiments, one of the C-RNTI and the PCI is included in the identifier received from the second apparatus 420, and the other one of the C-RNTI and the PCI may be identified or obtained by the first apparatus 410 separately.

[0103]

[0096] According to the embodiments of the present disclosure, to avoid changing the C- RNTI of an established connection, the ICBM or m-DCI m-TRP feature is configured to use a separate C-RNTI for the beams of neighboring cells (for example, the second cell) from the start. Furthermore, scrambling of the physical channels may use cell-specific initialization.

[0104]

[0097] In some example embodiments, at the beginning of the communication before 510, the first apparatus 410 may transmit, to the second apparatus 420, a capability indication that communications with the first cell using the first identifier and with the second cell using the second identifier are supported by the first apparatus 410. For example, the capability indication may be “beam / link specific scrambling” capability which indicates the support of the proposed solution in the present disclosure to the second apparatus 420 and allows the second apparatus 420 to start the operation of the proposed solution.

[0105]

[0098] Example processes for multi-link based communications will be described in detail below with reference to FIG. 6.

[0099] FIG. 6 illustrates a flowchart of an example signaling diagram 600 of C-RNTI switching in accordance with some example embodiments of the present disclosure. In this example, a UE 602 operates as an example implementation of the first apparatus 410 in FIG. 4, and a distributed unit (DU) for cell 1 604, a DU serving cell 2 606, and a centralized unit (CU) 608 may operate as example implementations of the second apparatus 420 in FIG. 4. The first cell may refer to as cell 1 and the first identifier may refer to as C-RNTI 1. The second cell may refer to as cell 2 and the second identifier may refer to as C-RNTI 2.

[0106]

[0100] As shown in FIG. 6, in the process 600, at 610, the UE 602 transmits measurement reports to the CU 608 and the DU serving cell 1 604. At 612, the CU 608 decides a multilink setup suitable for mobility. The multi-link setup, for example, may be an ICBM and / or m-DCI m-TRP based setup. For intra-DU case, a DU serving cell 1 and cell 2 may decide the multi-link setup suitable for mobility.

[0107]

[0101] At 614, the target cell (for example, cell 2) is prepared for multi-link usage. A C- RNTI 2 specific to cell 2 is obtained by the CU 608 and provided to the target cell. In intra-DU case, this step may be carried out at the DU serving cell 1 and cell 2. the DU serving cell 1 and cell 2 may request C-RNTI 2 from a network C-RNTI management entity.

[0108]

[0102] In an example, the TCI state of the neighboring cell is associated with a C-RNTI 2 allocated by cell 2. This association of a C-RNTI and a TCI state may be interpreted as that transmissions and receptions for the beam shall use the C-RNTI. In addition, the beam scrambling may be modified to be initialized by the PCI and C-RNTI of the beam. This shall be done for PDCCH, PDSCH, PUCCH, PUSCH.

[0109]

[0103] At 618, the CU 608 transmits TCI states for multi -link to the DU serving cell 1 604. The DU serving cell 1 may be configured with the TCI states which may be used for cell 2. The cell 2 specific TCI states may have C-RNTI 2 attached.

[0110]

[0104] At 620, the CU 608 may transmit a configuration of TCI states to the UE 602 via RRC signaling. The TCI states for cell 2 may be activated (not shown in Figure 6) for ICBM via an MAC CE. If multi-link has been configured according to Rel-18 m-DCI m- TRP, the TCI states likewise will have C-RNTI 2 attached. When data is scheduled after setup completed (622) on a link of cell 2, the scrambling of the physical links may be associated with C-RNTI 2 and a physical cell identifier (PCI, n_ID) of cell 2, and may be initialized as following: c init = fct(C-RNTI 2, n_ID = cell 2).

[0111] This may be applied to uplink and downlink, shared and control channels. DCI on cell 2 may use C-RNTI 2, while DCI on cell 1 may use C-RNTI 1. It should be noted that, the UE needs to apply cell-specific physical layer settings according to which beam is used. It also needs to use correct scrambling initialization.

[0112]

[0105] At 622, multi-link (intra-DU or inter-DU case for ICBM or m-DCI m-TRP) setup is completed. The TCI states may include PCI and link-specific C-RNTI for same or separate MAC entity.

[0113]

[0106] After 622, (not shown) the network may instruct the UE via DCI to use a specific TCI state that has been earlier configured (e.g. in step 620) for transmissions. With the linking of C-RNTI information to the TCI state an effect is achieved in that DCI also causes beam-specific scrambling to be used.

[0114]

[0107] At 624, the UE 602 may move into the coverage of cell 2. At 626, after the UE 602 moves completely into the coverage of cell 2, cell 2 may be configured as the serving cell, which means the common search space (CSS) is reconfigured. In the reconfiguration, the physical links not necessarily need to be reconfigured as they already have the correct C- RNTI and scrambling. The reconfiguration may maintain the multi-link setup or may release it. In intra-DU case, the role switch could be handled by the DU serving cell 1 and cell 2. According to the embodiments of the present disclosure, repeated beam switch may result in repeated physical channel reconfigurations, without touching the higher layers. Furthermore, comparing to the MCG SCG that transmissions on different cells have separate protocol stacks, transmissions happen on the same protocol stack according to the embodiments of the present disclosure.

[0115]

[0108] It should be noted that, when the multi-link is set up as m-DCI m-TRP, crossscheduling is possible. That is, the DCI on one link may indicate the transmission on another link. Therefore, according to the embodiments of the present disclosure, a DCI on cell 1 using C-RNTI 1 may contain a TCI state index pointing to a beam on cell 2 which will be using C-RNTI 2 and corresponding scrambling.

[0116]

[0109] FIG. 7 shows a flowchart of an example method 700 implemented at the first apparatus 410 in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 700 will be described from the perspective of the first apparatus 410 in FIG. 4.

[0117] [HO] At block 710, receiving, from a second apparatus, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, where the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell.

[0118] [Hl] At block 720, performing communications with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

[0119]

[0112] In some example embodiments, the second identifier is included in at least one TCI state information element (IE) for the second cell.

[0120]

[0113] In some example embodiments, the method 700 further comprises: receiving, via radio resource control (RRC) signaling, a configuration of TCI states, the configuration comprising the at least one TCI IE for the second cell; and receiving, via at least one of a Medium Access Control (MAC) Control Element (CE) or downlink control information (DCI), an indication for activating a TCI state for the second cell; and performing the communications after the activation of the TCI state for the second cell.

[0121]

[0114] In some example embodiments, the second identifier is included in a message other than a message configuring at least one TCI state.

[0122]

[0115] In some example embodiments, the method 700 further comprises: transmitting, to the second apparatus, a capability indication that communications with the first cell using the first identifier and with the second cell using the second identifier are supported by the first apparatus.

[0123]

[0116] In some example embodiments, the communication via the first beam is scrambled using the first identifier and the communication via the second beam is scrambled using the second identifier.

[0124]

[0117] In some example embodiments, the second apparatus comprises at least one of: a centralized unit of an access network device, a distributed unit of the access network device, or a cell-radio network temporary identifier (C-RNTI) management entity of the access network device.

[0118] In some example embodiments, the method 700 further comprises: applying a single transceiver and time domain multiplexing for the communications with the first cell and the second cell.

[0125]

[0119] FIG. 8 shows a flowchart of an example method 800 implemented at the second apparatus 420 in accordance with some example embodiments of the present disclosure. For the purpose of discussion, the method 800 will be described from the perspective of the second apparatus 420 in FIG. 4.

[0126]

[0120] At block 810, transmitting, to the first apparatus, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, where the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell.

[0127]

[0121] At block 820, transmitting, to the first apparatus, an indication that the first apparatus is to communicate with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

[0128]

[0122] In some example embodiments, the second identifier is included in at least one TCI state information element (IE) for the second cell.

[0129]

[0123] In some example embodiments, the method 800 further comprises: transmitting, via radio resource control (RRC) signaling, a configuration of TCI states, the configuration comprising the at least one TCI IE for the second cell; and transmitting, via at least one of a Medium Access Control (MAC) Control Element (CE) or downlink control information (DCI), an indication for activating the TCI state for the second cell.

[0130]

[0124] In some example embodiments, the second identifier is included in a message other than a message configuring at least one TCI state.

[0131]

[0125] In some example embodiments, the method 800 further comprises: receiving, from the first apparatus, a capability indication that communications with the first cell using the first identifier and with the second cell using the second identifier are supported by the first apparatus.

[0132]

[0126] In some example embodiments, the second apparatus comprises at least one of: a centralized unit of an access network device, a distributed unit of the access network device, or a cell-radio network temporary identifier (C-RNTI) management entity of the access network device.

[0133]

[0127] In some example embodiments, the method 800 further comprises: receiving, from a centralized unit of the access network device or a cell identifier management entity of the access network device, at least one of the first identifier of the first cell or the second identifier of the second cell.

[0134]

[0128] In some example embodiments, the method 800 further comprises: receiving, from a further access network device serving the second cell, the second identifier of the second cell.

[0135]

[0129] In some example embodiments, a first apparatus capable of performing any of the method 700 (for example, the first apparatus 410 in FIG. 4 may comprise means for performing the respective operations of the method 700. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the first apparatus 410 in FIG. 4.

[0136]

[0130] In some example embodiments, the first apparatus comprises means for receiving, from the second apparatus, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, wherein the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and means for performing communications with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

[0137]

[0131] In some example embodiments, the second identifier is included in at least one TCI state information element (IE) for the second cell.

[0138]

[0132] In some example embodiments, the first apparatus further comprises: means for receiving, via radio resource control (RRC) signaling, a configuration of TCI states, the configuration comprising the at least one TCI IE for the second cell; and means for receiving, via at least one of a Medium Access Control (MAC) Control Element (CE) or downlink control information (DCI), an indication for activating the TCI state for the second cell; and means for performing the communications after the activation of the TCI state for the second cell.

[0139]

[0133] In some example embodiments, the second identifier is included in a message other than a message configuring at least one TCI state.

[0134] In some example embodiments, the first apparatus further comprises: means for transmitting, to the second apparatus, a capability indication that communications with the first cell using the first identifier and with the second cell using the second identifier are supported by the first apparatus.

[0140]

[0135] In some example embodiments, the communication via the first beam is scrambled using the first identifier and the communication via the second beam is scrambled using the second identifier.

[0141]

[0136] In some example embodiments, the second apparatus comprises at least one of a centralized unit of an access network device, a distributed unit of the access network device, or a cell-radio network temporary identifier (C-RNTI) management entity of the access network device.

[0142]

[0137] In some example embodiments, the first apparatus further comprises: means for applying a single transceiver and time domain multiplexing for the communications with the first cell and the second cell.

[0143]

[0138] In some example embodiments, the first apparatus further comprises means for performing other operations in some example embodiments of the method 700 or the first apparatus 410. 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.

[0144]

[0139] In some example embodiments, a second apparatus capable of performing any of the method 800 (for example, the second apparatus 420 in FIG. 4 may comprise means for performing the respective operations of the method 800. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the second device 420 in FIG. 4.

[0145]

[0140] In some example embodiments, the second apparatus comprises means for transmitting, to a first apparatus, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, wherein the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and means for transmitting, to the first apparatus, an indication that the first apparatus is to communicate with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

[0146]

[0141] In some example embodiments, the second identifier is included in at least one TCI state information element (IE) for the second cell.

[0147]

[0142] In some example embodiments, the second apparatus further comprises: means for transmitting, via radio resource control (RRC) signaling, a configuration of TCI states, the configuration comprising the at least one TCI IE for the second cell; and means for transmitting, via at least one of a Medium Access Control (MAC) Control Element (CE) or downlink control information (DCI), an indication for activating the TCI state for the second cell.

[0148]

[0143] In some example embodiments, the second identifier is included in a message other than a message configuring at least one TCI state.

[0149]

[0144] In some example embodiments, the second apparatus further comprises: means for receiving, from the first apparatus, a capability indication that communications with the first cell using the first identifier and with the second cell using the second identifier are supported by the first apparatus.

[0150]

[0145] In some example embodiments, the second apparatus comprises at least one of: a centralized unit of an access network device, a distributed unit of the access network device, or a cell-radio network temporary identifier (C-RNTI) management entity of the access network device.

[0151]

[0146] In some example embodiments, the second apparatus comprises a distributed unit of an access network device, the second apparatus further comprises: means for receiving, from a centralized unit of the access network device or a cell identifier management entity of the access network device, at least one of the first identifier of the first cell or the second identifier of the second cell.

[0152]

[0147] In some example embodiments, the second apparatus comprises an access network device serving the first cell, the second apparatus further comprises: means for receiving, from a further access network device serving the second cell, the second identifier of the second cell.

[0153]

[0148] In some example embodiments, the second apparatus further comprises means for performing other operations in some example embodiments of the method 800 or the second apparatus 420. 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.

[0154]

[0149] FIG. 10 is a simplified block diagram of a device 900 that is suitable for implementing example embodiments of the present disclosure. The device 900 may be provided to implement a communication device, for example, the first apparatus 410 or the second apparatus 420 as shown in FIG. 4. As shown, the device 900 includes one or more processors 910, one or more memories 920 coupled to the processor 910, and one or more communication modules 940 coupled to the processor 910.

[0155]

[0150] The communication module 940 is for bidirectional communications. The communication module 940 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 940 may include at least one antenna.

[0156]

[0151] The processor 910 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 900 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0157]

[0152] The memory 920 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 924, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk (DVD), an optical disk, a laser disk, and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random access memory (RAM) 922 and other volatile memories that will not last in the power-down duration.

[0158]

[0153] A computer program 930 includes computer executable instructions that are executed by the associated processor 910. The instructions of the program 930 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 930 may be stored in the memory, e.g., the ROM 924. The processor 910 may perform any suitable actions and processing by loading the program 930 into the RAM 922.

[0159]

[0154] The example embodiments of the present disclosure may be implemented by means of the program 930 so that the device 900 may perform any process of the disclosure as discussed with reference to FIG. 1 to FIG. 8. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0160]

[0155] In some example embodiments, the program 930 may be tangibly contained in a computer readable medium which may be included in the device 900 (such as in the memory 920) or other storage devices that are accessible by the device 900. The device 900 may load the program 930 from the computer readable medium to the RAM 922 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0161]

[0156] FIG. 10 shows an example of the computer readable medium 1000 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 1000 has the program 930 stored thereon.

[0162]

[0157] 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.

[0163]

[0158] 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.

[0164]

[0159] 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.

[0165]

[0160] 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.

[0166]

[0161] 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.

[0167]

[0162] 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.

[0168]

[0163] 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

CLAIMS:

1. A first apparatus comprising: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: receive, from a second apparatus, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, wherein the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and perform communications with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

2. The first apparatus of claim 1, wherein the second identifier is included in at least one TCI state information element (IE) for the second cell.

3. The first apparatus of claim 2, wherein the at least one memory and the at least one processor further cause the first apparatus to: receive, via radio resource control (RRC) signaling, a configuration of TCI states, the configuration comprising the at least one TCI IE for the second cell ; and receive, via at least one of a Medium Access Control (MAC) Control Element (CE) or downlink control information (DCI), an indication for activating a TCI state for the second cell; and perform the communications after the activation of the TCI state for the second cell.

4. The first apparatus of claim 1, wherein the second identifier is included in a message other than a message configuring at least one TCI state.

5. The first apparatus of any of claims 1 to 4, wherein the at least one memory andthe at least one processor further cause the first apparatus to: transmit, to the second apparatus, a capability indication that communications with the first cell using the first identifier and with the second cell using the second identifier are supported by the first apparatus.

6. The first apparatus of any of claims 1 to 5, wherein the communication via the first beam is scrambled using the first identifier and the communication via the second beam is scrambled using the second identifier.

7. The first apparatus of any of claims 1 to 6, wherein the second apparatus comprises at least one of a centralized unit of an access network device, a distributed unit of the access network device, or a cell-radio network temporary identifier (C-RNTI) management entity of the access network device.

8. The first apparatus of any of claims 1 to 7, wherein the at least one memory and the at least one processor further cause the first apparatus to: apply a single transceiver and time domain multiplexing for the communications with the first cell and the second cell.

9. 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 first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, wherein the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and transmit, to the first apparatus, an indication that the first apparatus is to communicate with the first cell via the first beam by using the first identifier and with thesecond cell via the second beam by using the second identifier.

10. The second apparatus of claim 9, wherein the second identifier is included in at least one TCI state information element (IE) for the second cell.

11. The second apparatus of claim 10, wherein the at least one memory and the at least one processor further cause the second apparatus to: transmit, via radio resource control (RRC) signaling, a configuration of TCI states, the configuration comprising the at least one TCI IE for the second cell; and transmit, via at least one of a Medium Access Control (MAC) Control Element (CE) or downlink control information (DCI), an indication for activating a TCI state for the second cell.

12. The second apparatus of claim 9, wherein the second identifier is included in a message other than a message configuring at least one TCI state.

13. The second apparatus of any of claims 9 to 12, wherein the at least one memory and the at least one processor further cause the second apparatus to: receive, from the first apparatus, a capability indication that communications with the first cell using the first identifier and with the second cell using the second identifier are supported by the first apparatus.

14. The second apparatus of any of claims 9 to 13, wherein the second apparatus comprises at least one of: a centralized unit of an access network device, a distributed unit of the access network device, or a cell-radio network temporary identifier (C-RNTI) management entity of the access network device.

15. The second apparatus of any of claims 9 to 14, wherein the second apparatus comprises a distributed unit of an access network device, and the at least one memory andthe at least one processor further cause the second apparatus to: receive, from a centralized unit of the access network device or a cell identifier management entity of the access network device, at least one of the first identifier of the first cell or the second identifier of the second cell.

16. The second apparatus of any of claims 9 to 15, wherein the second apparatus comprises an access network device serving the first cell, and the at least one memory and the at least one processor further cause the second apparatus to: receive, from a further access network device serving the second cell, the second identifier of the second cell.

17. A method comprising: receiving, from a second apparatus, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, wherein the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and performing communications with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

18. A method comprising: transmitting, to a first apparatus, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, wherein the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and transmitting, to the first apparatus, an indication that the first apparatus is to communicate with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

19. A first apparatus comprising means for:receiving, from a second apparatus, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell, wherein the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and performing communications with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

20. A second apparatus comprising means for: transmitting, to a first apparatus, a first identifier for a first beam of a first cell and a second identifier for a second beam of a second cell , wherein the second identifier is associated with at least one transmission configuration indicator (TCI) state of the second cell; and transmitting, to the first apparatus, an indication that the first apparatus is to communicate with the first cell via the first beam by using the first identifier and with the second cell via the second beam by using the second identifier.

21. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 17 or the method of claim 18.

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