Cell change in mac-based mobility

Abstract

Example embodiments of the present disclosure relate to cell change in media access control (MAC) based mobility. In one method, a first apparatus receives, from a second apparatus via radio resource signaling (RRC) signaling, a cell configuration indicating at least one secondary cell (SCell). The first apparatus receives, from the second apparatus via MAC signaling, a first indication that a SCell of the at least one SCell is changed to a primary cell (PCell).

Description

Technical Field

[0001] Various exemplary embodiments of this disclosure are generally related to the telecommunications field, and more particularly to methods, apparatuses, devices, and computer-readable storage media for cell changing in Media Access Control (MAC) based mobility. Background Technology

[0002] In the 5G architecture, Layer 3 (L3) mobility (sometimes also called L3 mobility) can be characterized by measurements sent by the user equipment (UE) using Radio Resource Control (RRC) signaling and by handover (HO) commands issued by the network using RRC signaling. For example, the decision about the handover is made from the RRC layer after the network indicates to the UE that it will perform a handover. Lower Layer Triggered Mobility (LTM) allows handover to be triggered at the MAC layer. However, in LTM, configuration still needs to be provided from the RRC layer. Summary of the Invention

[0003] In a first aspect of this disclosure, a first apparatus is provided. The first apparatus includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus to at least: receive, via RRC signaling, a cell configuration indicating at least one secondary cell from a second apparatus; and receive via MAC signaling, a first indication from the second apparatus that a secondary cell among the at least one secondary cell has been changed to a primary cell.

[0004] In a second aspect of this disclosure, a second apparatus is provided. The second apparatus includes: at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus to at least: send a cell configuration instructing at least one secondary cell for the first apparatus to a first apparatus via RRC signaling; and send a first indication to the first apparatus via MAC signaling regarding the change of one of the at least one secondary cell to a primary cell for the first apparatus.

[0005] In a third aspect of this disclosure, a method is provided at a first device. The method includes: receiving, via RRC signaling, a cell configuration indicating at least one secondary cell from a second device; and receiving, via MAC signaling, a first indication from the second device that a secondary cell among the at least one secondary cell has been changed to a primary cell.

[0006] In a fourth aspect of this disclosure, a method is provided at a second device. The method includes: sending a cell configuration indicating at least one secondary cell for the first device via RRC signaling; and sending a first indication to the first device via MAC signaling regarding a secondary cell among the at least one secondary cell being changed to a primary cell for the first device.

[0007] In a fifth aspect of this disclosure, a first apparatus is provided. The first apparatus includes: components for receiving, via RRC signaling, a cell configuration indicating at least one secondary cell from a second apparatus; and components for receiving, via MAC signaling, a first indication from the second apparatus that a secondary cell among the at least one secondary cell has been changed to a primary cell.

[0008] In a sixth aspect of this disclosure, a second apparatus is provided. The second apparatus includes: components for transmitting to a first apparatus via RRC signaling an indication of cell configuration for at least one secondary cell for the first apparatus; and components for transmitting to the first apparatus via MAC signaling a first indication that a secondary cell among the at least one secondary cell has been changed to a primary cell for the first apparatus.

[0009] In a seventh aspect of this disclosure, a computer-readable medium is provided. The computer-readable medium includes instructions stored thereon for causing a device to perform at least one of the methods according to the third and fourth aspects.

[0010] It should be understood that the summary portion is not intended to identify key or essential features of the embodiments of this disclosure, nor is it intended to limit the scope of this disclosure. Other features of this disclosure will become readily apparent from the following description. Attached Figure Description

[0011] Some exemplary embodiments will now be described with reference to the accompanying drawings, in which: Figure 1 An example communication environment in which example embodiments of the present disclosure may be implemented is shown; Figure 2 A schematic diagram of an example architecture 200 for switching using a single RRC entity is shown; Figure 3 An example scenario of MAC-based mobility is shown; Figure 4 The signaling flow illustrating an example CA procedure in a RAN split architecture is shown; Figure 5 The overall process for cell change in MAC-based mobility is illustrated according to some example embodiments of the present disclosure; Figure 6 Signaling flows for cell changes in MAC-based mobility are shown according to some example embodiments of this disclosure; Figure 7 The process for cell change in MAC-based mobility is illustrated according to some example embodiments of the present disclosure; Figure 8 A flowchart is shown illustrating a method implemented at a first device according to some exemplary embodiments of the present disclosure; Figure 9 A flowchart is shown illustrating a method implemented at a second device according to some example embodiments of the present disclosure; Figure 10 A simplified block diagram of a device suitable for implementing example embodiments of the present disclosure is shown; and Figure 11 A block diagram of an example computer-readable medium according to some example embodiments of the present disclosure is shown.

[0012] Throughout the accompanying drawings, the same or similar reference numerals denote the same or similar elements. Detailed Implementation

[0013] The principles of the exemplary embodiments will now be described with reference to some example embodiments. It should be understood that these embodiments are described for illustrative purposes only and to help those skilled in the art to understand and implement this disclosure, without imposing any limitation on the scope of this disclosure. The embodiments described herein can be implemented in various ways other than those described below.

[0014] In the following description and claims, unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure pertains.

[0015] References to "an embodiment," "embodiment," "example embodiment," etc., in this disclosure indicate that the described embodiment may include a particular feature, structure, or characteristic, but not every embodiment necessarily includes that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a particular feature, structure, or characteristic is described in connection with an embodiment, whether explicitly described or not, it is believed that its influence on such feature, structure, or characteristic in conjunction with other embodiments is within the knowledge of those skilled in the art.

[0016] It should be understood that although the terms “first,” “second,” etc., may be used before the nouns(s) herein to describe various elements, these elements are not limited by these terms. These terms are only used to distinguish one element from another, and they do not restrict the order of the nouns(s). For example, without departing from the scope of the exemplary embodiments, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0017] As used herein, “at least one of the following: ” and “at least one of ” and similar expressions, wherein the list of two or more elements is connected by “and” or “or”, means at least any one of the elements, or at least any two or more of the elements, or at least all of the elements.

[0018] As used herein, unless explicitly stated otherwise, the execution step “in response to A” does not indicate that the step is executed immediately after “A” occurs, but may include one or more intermediate steps.

[0019] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments. As used herein, the singular forms “a,” “an,” and “the” are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the terms “comprising,” “including,” “having,” “possessing,” “containing,” and / or “covering,” as used herein, specify the presence of the stated features, elements, and / or components, but do not exclude the presence or addition of one or more other features, elements, components, and / or combinations thereof.

[0020] As used in this application, the term "circuit system" may refer to one or more of the following: (a) Hardware circuit implementation only (such as implementation in analog and / or digital circuits only), and (b) A combination of hardware circuitry and software, such as (if applicable): (i) A combination of (multiple) analog and / or digital hardware circuits and software / firmware, and (ii) Any part of a hardware processor having software (including (multiple) digital signal processors, software, and (multiple) memories, which work together to enable a device (such as a mobile phone or server) to perform various functions), and (c) A hardware circuit (multiple) and / or a processor (multiple) that requires software (e.g., firmware) for operation, such as being a microprocessor (multiple) or part of a microprocessor, but which may not exist when the software is not required to operate.

[0021] This definition of "circuit" applies to all uses of the term in this application, including in any claim. As another example, as used herein, the term "circuit" also covers only hardware circuitry or a processor (or multiple processors), or a portion of hardware circuitry or a processor and its accompanying software and / or firmware. For example, and if applicable to a particular claim element, the term "circuit" also covers baseband integrated circuits or processor integrated circuits used in mobile devices or servers, cellular network devices, or other computing or networking devices.

[0022] As used herein, the term "communication network" means a network that conforms to any suitable communication standard, such as New Radio (NR), Long Term Evolution (LTE), LTE-A Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed ​​Packet Access (HSPA), Narrowband Internet of Things (NB-IoT), etc. Furthermore, communication between user equipment and network equipment in a communication network can be performed according to any suitable generation of communication protocol, including but not limited to first-generation (1G), second-generation (2G), 2.5G, 2.75G, third-generation (3G), fourth-generation (4G), 4.5G, fifth-generation (5G), 5G Advanced, sixth-generation (6G) communication protocols, wireless LAN communication protocols (such as IEEE 802.11), and / or any other currently known or future protocols. Furthermore, communication can utilize any suitable wireless communication technology, including 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 Access (OFDM), Discrete Fourier Transform Extended OFDM (DFT-s-OFDM), and / or any other currently known or future-developed technology. Embodiments can be applied to a variety of communication systems. Given the rapid development in communications, there will naturally be future types of communication technologies and systems that can implement this disclosure. This should not be construed as limiting the scope to the aforementioned systems.

[0023] As used herein, the term "network device" refers to a node in a communications network through which user equipment accesses the network and receives services. Network devices can include base stations (BS) or access points (APs), such as Node Bs (NodeBs or NBs), evolved Node Bs (eNodeBs or eNBs), NR NBs (also known as gNBs), Remote Radio Units (RRUs), Radio Heads (RHs), Remote Radio Heads (RRHs), relays, Integrated Access and Backhaul (IAB) nodes, low-power nodes (such as femtoseconds, home gNBs (HgNBs), picoseconds), non-terrestrial network (NTN) or non-terrestrial network equipment (such as satellite network equipment, low Earth orbit (LEO) satellites, and geostationary Earth orbit (GEO) satellites), spacecraft network equipment, etc., depending on the terminology and technology applied. In some example embodiments, network devices may utilize a Radio Access Network (RAN) split architecture, where the network device includes a Central Unit (CU) and Distributed Units (DUs).

[0024] The term "user equipment" 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 user equipment (UE), user station (SS), portable user station, mobile station (MS), or access terminal (AT). Terminal devices can include, but are not limited to, mobile phones, cellular phones, smartphones, Voice over IP (VoIP) phones, wireless local loop phones, tablets, wearable terminal devices, personal digital assistants (PDAs), portable computers, desktop computers, image acquisition terminal devices (such as digital cameras), gaming terminal devices, music storage and playback devices, in-vehicle wireless terminal devices, wireless endpoints, mobile stations, laptop embedded devices (LEE), laptop mounted devices (LME), USB dongles, smart devices, wireless client devices (CPE), 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 the context of industrial and / or automated processing chains), consumer electronic devices, devices operating on commercial and / or industrial wireless networks, etc. User equipment may also correspond to the mobile terminal (MT) portion of an IAB node (e.g., a relay node). In the following description, the terms "terminal equipment," "user equipment," "user gear," and "UE" are used interchangeably.

[0025] As used herein, the terms “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” can refer to any resource used to perform communication, such as communication between a terminal device and a network device, including resources in the time domain, frequency domain, spatial domain, code domain, or any other combination of time, frequency, spatial, and / or code domain resources used to implement communication. In the following, unless explicitly stated otherwise, resources in both the frequency and time domains will be used as examples of transmission resources used to describe some exemplary embodiments of this disclosure. Note that the exemplary embodiments of this disclosure are equally applicable to other resources in other domains.

[0026] Figure 1 An example communication environment 100 in which exemplary embodiments of the present disclosure may be implemented is shown. In the communication environment 100, a plurality of communication devices, including a first device 110 and a second device 120, can communicate with each other. The first device 110 may be a user equipment, such as a UE. The second device 120 may be a network device, such as a BS or gNB.

[0027] In some example embodiments, if the first device 110 is a terminal device and the second device 120 is a network device, the link from the second device 120 to the first device 110 is referred to as a downlink (DL), and the link from the first device 110 to the second device 120 is referred to as an uplink (UL). In the DL, the second device 120 is a transmitting (TX) device (or transmitter), and the first device 110 is a receiving (RX) device (or receiver). In the UL, the first device 110 is a TX device, and the second device 120 is an RX device.

[0028] In some example embodiments, the second device 120 may operate as a gNB utilizing a RAN split architecture, wherein the gNB may include a gNB-CU and one or more gNB-DUs. In this architecture, different gNB-DUs may provide one or more cells to the first device 110.

[0029] It should be understood that Figure 1 The number of devices and their connections shown is for illustrative purposes only and does not imply any limitation. The communication environment 100 may include any suitable number of devices configured to implement the exemplary embodiments of this disclosure.

[0030] In the communication environment 100, the second device 120 can provide a coverage area, which may be referred to as a service area. Within the service area, the second device 120 can provide one or more serving cells in which the first device 110 can be served. In a mobility scenario, when the first device 110 moves from one cell to an adjacent cell, a handover to the adjacent cell may be triggered for the first device 110.

[0031] MAC-based mobility (also known as MAC-level mobility or MAC mobility) can be enabled in communication environment 100. In MAC mobility, the concept of a "cell at MAC" is introduced to grant greater autonomy to lower layers (such as the physical (PHY) and MAC layers), such as... Figure 2 The diagram illustrates an example architecture 200 for handover utilizing a single RRC entity. In the concept of a "cell at MAC," the entity cell is within the MAC layer, and handovers between cells are managed at the MAC layer. The Packet Data Convergence Protocol (PDCP) and Radio Link Control (RLC) layers are not linked to a single cell and are not rebuilt during MAC layer handovers. In cases where MAC mobility-related features are deployed in a RAN split architecture, CU-DU signaling exchange can be reduced because the RRC layer (e.g., located at the CU) may not be involved during handovers managed at the MAC layer (e.g., located at the DU).

[0032] This architecture 200 offers several benefits. First, mobility can be hidden from higher layers (such as PDCP, RLC, and even RRC layers). The reconstruction of PDCP, RLC, and RRC layers can be decoupled from handover. Second, a streamlined handover process can be achieved. Because mobility is hidden from the RRC layer, handover-related parameter updates may only include MAC and PHY-related parameters. These parameters can be pre-configured and / or organized in a channel-specific manner. For example, a cell handover command via MAC signaling may only include the target cell's configuration group identifier (ID). The target cell's configuration index can be sent to the UE via lower layers. Third, streamlined preparation can be achieved. By defining and managing inter-cell mobility at the MAC layer, it frees up the CU (or RRC layer entity) from candidate cell preparation.

[0033] Communication Environment 100 can also implement Carrier Aggregation (CA), which can be a deployment feature for both LTE and NR. In CA, different carriers from different cells can be aggregated at the MAC layer, and different carriers can have the same RLC and PDCP layers, similar to... Figure 2 Architecture 200. To implement CA for the first device 110, the second device 120 can provide services to the first device 110's primary cell (PCell) and one or more secondary cells (SCells). The SCells can be configured and indicated to the first device 110 by RRC signaling.

[0034] Figure 3 Example scenario 300 of MAC-based mobility is shown. (e.g.) Figure 3 As shown, cells 301 and 303 are on frequency 1, while cells 302 and 304 are on frequency 2. The first device 110 can move between different cells on the same frequency, for example, from cell 401 to cell 403, or from cell 402 to cell 404. Cells 402 and 404 on frequency 2 are optional and may depend on the CA capability of the first device 110, as described below.

[0035] CA (Carrier Access Request) can be used to achieve higher throughput for the first device 110. The carriers in the CA can be on different frequencies, and there can be one PCell on the primary carrier and one or more SCells on the secondary carriers(s). The primary carrier can be used to establish a connection to the network. The secondary carriers can be used to provide additional throughput to the first device 110. Secondary carriers can be added / removed or activated / deactivated without affecting the connection. In the CA, if the link quality of the primary carrier is poor, a change in connection may result in a handover to a new cell. During the handover, the MAC layer can be reset using a refreshed Hybrid Automatic Repeat Request (HARQ) buffer.

[0036] Figure 4 The signaling flow of an example CA procedure 400 in a RAN split architecture is shown. In other systems without formal CU-DU splitting, the separation of MAC and higher protocol layers may still exist, where the separation can be seen in logical or physical interfaces (e.g., where the MAC processing entity is physically located closer to the antenna than the higher protocol layer processing entity). Figure 4 As shown, based on the L3 measurement report in step 1, CU 403 can decide to add or remove SCell 405, and in step 2, it sends this decision to DU 402 (which can provide PCell 404) via a UE context modification request. In response to the UE context modification request in step 2, DU 402 can send a UE context modification response to CU 403 in step 3. Based on the UE context modification response, CU 403 can send an indication of SCell configuration for at least one SCell of UE 401 via RRC signaling (such as the RRCReconfiguration message in step 4). In response to the RRCReconfiguration message, UE 401 can send an (431) RRCReconfiguration completion message to CU 403 in step 5.

[0037] In step 6, DU 402 can decide to activate or deactivate SCells on the list provided in the RRCReconfiguration message. For example, DU 402 can blindly activate SCells in the SCell list. Alternatively, DU 402 can activate SCells based on load or channel conditions. DU 402 can then send MAC signaling with a set of deactivated SCells (including SCell 405) to be activated. For example, DU 402 can send a MAC Control Unit (MAC-CE) enhanced SCell activation or deactivation command to UE 401 in step 7. In this example, the MAC-CE enhanced SCell activation or deactivation command may include an aperiodic Tracking Reference Signal (TRS) for Faster Channel State Information (CSI) reporting measurements. In another example, DU 402 can send a MAC-CE SCell activation command without an aperiodic TRS to UE 401 in step 8. In response to the received MAC signaling, UE 401 can perform CSI channel measurement for SCell 405 in step 9, and start receiving DL data from the activated SCell 405 in step 10 to achieve higher throughput.

[0038] like Figure 4 As shown, entities at the RRC layer can still function in PCell changes that have current L3 mobility or even LTM. For example, Figure 4 The CA baseline shown can support up to 32 serving cells. The MAC entity at the MAC layer can control which SCell(s) will be activated and deactivated without notifying the RRC layer, but PCell changes still involve the RRC layer. These CA serving cells are on different carriers. Measurement objects need to be configured for all serving frequencies so that the network can know the SCell's quality even if it is deactivated at the MAC layer. This is inefficient in terms of latency and signaling overhead because the RRC entity may not need to know which physical resources are serving the UE, similar to how beamforming serving the UE is not visible to the RRC entity.

[0039] According to some example embodiments, a solution for cell changes in MAC-based mobility is provided. In this solution, a second device 120 sends an indication for cell configuration for at least one SCell of the first device 110 via RRC signaling. The second device 120 sends an indication (referred to as a first indication) via MAC signaling that an SCell in at least one SCell is changed to a PCell for the first device 110.

[0040] In this way, after MAC-level mobility occurs, the MAC entity can perform PCell changes without involving the RRC entity, because the MAC entity has the authority to decide which cell is the PCell and which cell is the SCell.

[0041] The proposed solution can be based on the concept of “cell at MAC” with a CA framework. Figure 5 A general procedure 500 for cell change in MAC mobility with a CA framework is illustrated according to some example embodiments. In procedure 500, UE 501 may be an example of a first device 110. SCell 503 or PCell 504, MAC entity (MAC for short) 502 or RRC entity (RRC for short) 505 may be provided by a second device 120.

[0042] like Figure 5As shown, UE 501 can send (507) an L3 measurement report to RRC 505 via MAC 502. In some example embodiments, L3 measurements can be triggered under certain events, such as measurements from neighboring cells exceeding a threshold. After RRC 505 receives (511) the L3 measurement report, RRC 505 can send (513) a UE context modification request to MAC 502, for example, to add or remove a SCell in the UE context. For example, RRC 505 can decide to add or remove SCell 503 and send this decision to MAC 502 via the UE context modification request. After MAC 502 receives (515) the UE context modification request, MAC 502 can send (517) a UE context modification response to RRC 505. Accordingly, RRC 505 can receive (519) a UE context modification response from MAC 502.

[0043] RRC 505 can send an (521) RRCReconfiguration message to UE 501 via MAC 502. This RRCReconfiguration message may include a list of cell configurations. The cell configurations may indicate multiple pre-configured serving cells, which can be, for example... Figure 4 The shown frequencies may be the same or different. Multiple serving cells may include one cell that is traditionally currently operating as a PCell and other cells that are operating as SCells. In some example embodiments, the RRCReconfiguration message may provide pre-configured common resources for both the (multiple) SCells and the unified PSCell / Scell ​​(GCell) configuration. After UE 501 can receive the (527) RRCReconfiguration message, UE 501 may send the (529) RRCReconfiguration complete message to RRC 505 via MAC 502. Accordingly, RRC 505 may receive the (535) RRCReconfiguration complete message.

[0044] UE 501 can send (537) Layer 1 (L1) measurement reports to MAC 502 for flexible L1 measurement management. The L1 measurement reports can be correlated with CSI feedback and load conditions to assist MAC 502 in making decisions (541). Accordingly, MAC 502 can receive (539) L1 measurement reports from UE 501. Then, if MAC mobility occurs, MAC 502 can determine (541) which cell is the PCell and which cell is the Scell. In some example embodiments, the decision can be made based on the UE's capabilities at the MAC layer (541).

[0045] Then, MAC 502 may send (543) the decision result to UE 501 via a new MAC CE or by multiplexing the cell handover command carried in the MAC CE defined for LTM. In some example embodiments, MAC 502 may send (543) a MAC message including incremental Scell ​​configuration. The incremental Scell ​​configuration may include Physical Uplink Control Channel (PUCCH) configuration, Dedicated Random Access Channel (RACH) configuration, Synchronization Signal Block (SSB) Measurement Timing Configuration (SMTC), and / or Potential Timing Advance Group (TAG) update.

[0046] After UE 501 receives the (545) MAC message from MAC 502, UE 501 may send the (547) MAC response to MAC 502. Accordingly, MAC 502 may receive the (549) MAC response from UE 501.

[0047] MAC 502 can send a (551) MAC CE command to UE 501 indicating PCell and SCell activation. The MAC CE command can indicate a single cell role swap or a cell group role swap, and indicate a MAC reset (and RLC reset). After UE 501 receives the (553) MAC CE command, UE 501 can send a (555) MAC CE SCell activation response to MAC 502. UE 501 can then move (559) to the new PCell 504 and receive (561) DL data from SCell 503 for higher throughput. In a RAN split architecture, there is no need to update the CU from MAC 502. If the CU needs to know where the UE is located, the CU can request it from MAC 502.

[0048] According to some example embodiments, the CA framework can be reused to allow pre-configuration of a cell as an SCell via RRC signaling, and PCell changes between those pre-configured serving cells via the MAC layer. References will follow below. Figure 6 and 7 Describe some example implementations.

[0049] Figure 6 The following diagram illustrates a signaling flow for a cell change process 600 in MAC-based mobility, according to some example embodiments of this disclosure. Reference will be made to this diagram for discussion purposes. Figure 1 For example, process 600 is discussed using a first device 110 and a second device 120. In some example embodiments, the first device 110 may be discussed as a terminal device (e.g., a UE). The second device 120 may be discussed as a network device (e.g., a BS or gNB).

[0050] In process 600, the second device 120 sends (605) a cell configuration to the first device 110 via RRC signaling. Correspondingly, the first device 110 receives (610) a cell configuration from the second device 120 via RRC signaling. The cell configuration indicates at least one SCell for the first device 110. In some example embodiments, the cell configuration may be carried in an RRC reconfiguration message.

[0051] In some example embodiments, the secondary cell in at least one SCell and the previous PCell are on the same carrier frequency. Multiple SCells and PCells may also be on different carrier frequencies. For example, cell configuration may indicate multiple serving cells that can be pre-configured for RRC on the same or different frequencies. Among the multiple serving cells, one cell currently operates as a PCell, while other cells operate as SCells. In some example embodiments, at least one SCell may include multiple SCells on the same carrier frequency. In this case, at most one of the multiple SCells can be active on the carrier frequency.

[0052] The second device 120 sends (625) a first indication to the first device 110 via MAC signaling regarding the change of at least one SCell to a PCell for the first device 110. For example, if MAC-based mobility occurs, the MAC entity of the second device 120 may indicate which serving cell in at least one SCell in the cell configuration will be the new PCell. Accordingly, the first device 110 receives (630) the first indication from the second device 120 via MAC signaling. In some example embodiments, the MAC signaling may be a MAC CE or a cell handover command carried in a MAC CE defined for LTM.

[0053] In some example embodiments, the MAC layer can be used to configure or activate necessary resources for the PCell that are unavailable when the PCell is operating as an SCell. For example, such as Figure 6 As shown, the second device 120 can send (631) a second indication for activating a resource configured to be used after the SCell is changed to the PCell. Accordingly, the first device 110 can receive (633) the second indication. The second indication can be included in the same MAC signaling or MACCE as the first indication, or it can be included in a separate MAC message or MACCE.

[0054] In some example embodiments, resources can be pre-configured, and a second instruction can be used to enable the pre-configured resources so that they can be activated after the SCell is changed to the PCell. For example, the second device 120 can send a configuration of resources configured for use after the secondary cell is changed to the primary cell to the first device 110. This configuration can be included in the cell configuration received via RRC signaling (610) or sent in a separate RRC message. In response to the second instruction, the first device 110 can activate the resources.

[0055] In some other example embodiments, the second instruction may instruct or configure the resource to be activated after the SCell is changed to the PCell. In this case, the first device 110 may activate the resource in response to the first instruction that the SCell be changed to the PCell.

[0056] In response to the first instruction, the first device 110 can activate (635) the SCell and change (637) the SCell to the PCell. Other serving cells configured in the cell configuration operate as SCells, which are activated or deactivated by the current SCell activation / deactivation MAC CE (as an example of MAC signaling). This ensures that only one serving cell is activated per frequency.

[0057] Then, the first device 110 can send a (640) cell activation response to the second device 120 via MAC signaling to indicate that the SCell has been activated and changed to the PCell. Accordingly, the second device 120 can receive a (645) cell activation response from the first device 110 via MAC signaling. In this way, when MAC-level mobility occurs for a PCell change, there is no RRC involvement or (full) MAC reset or C-RNTI change, thereby improving mobility efficiency and network capacity.

[0058] The following will refer to Figure 7 Describe an example process for MAC-based mobility. In, for example... Figure 7 In the example process 700 shown, the first device 110 can operate as UE 501, and the second device 120 can operate as gNB, providing PCell 504 or SCell 503 and including MAC 502 (which may be located at DU) and RRC 505 (which may be located at CU).

[0059] As shown in procedure 700, RRC 505 may send an (705) RRCReconfiguration message to UE 501 via MAC 502. This RRCReconfiguration message may include indications of cell configurations, such as a cell configuration list, for at least one SCell of UE 501. Accordingly, UE 501 may receive an (711) RRCReconfiguration message. In some example embodiments, at least one SCell and the previous PCell are on the same carrier frequency or on different carrier frequencies.

[0060] For example, with Figure 3 Taking scenario 300 as an example, cell 301 on frequency 1 is the cell when UE 501 obtains a connection. RRC 505 can additionally configure cell 303 on frequency 1 and cells 302 and 304 on frequency 2 as serving cells for UE 501. Cells 303 and 304 are deactivated cells.

[0061] In response to the RRCReconfiguration message, UE 501 can send an RRCReconfiguration complete message (713) to RRC 505. Accordingly, RRC 505 can receive an RRCReconfiguration complete message (719). MAC 502 can determine which cell in the SCell configuration (721) is PCell 504 and which cell is SCell 503. In this way, which cell serves as the PCell and which(s) cells serve as the active SCell for serving the UE can be controlled at the MAC layer without involving the RRC layer.

[0062] Then, MAC 502 can send a MAC CE command to UE 501 instructing the PCell and SCell. In some example embodiments, additional configuration can be provided via the MAC layer if needed. This PCell / SCell activation can be performed between cells from the same frequency. In some example embodiments, activation can be allowed only from one cell at its maximum frequency, and only one of all activated cells can be used as the PCell, such as... Figure 3 As shown. In this way, it can be ensured that only one serving cell is active per frequency.

[0063] After UE 501 receives the (725) MAC CE command from MAC 502, UE 501 can send the (727) MAC CE SCell activation response to MAC 502. Correspondingly, MAC 502 can receive the (729) MAC CE SCell activation response from UE 501. In some example embodiments, timing advance (TA) can be managed on a group basis. Commands to keep TAG updated can be reused to activate PCell and SCell. In this case, UE 501 does not need to perform the RACH procedure. Upon receiving the (725) MAC CE, if the TAG has been updated, UE 501 can respond with a MAC cell activation response message terminated at the MAC layer.

[0064] Then, UE 501 can move (731) to PCell 504 and receive (733) DL data from SCell 503 to achieve higher throughput. Now, UE 501 is connected to PCell 504 and begins using SCell 503 to achieve high throughput.

[0065] Figure 8 A flowchart of an example method 800 implemented at a first device according to some example embodiments of the present disclosure is shown. For the purposes of discussion, [the following will be discussed]. Figure 1 Method 800 is described by the angle of the first device 110 in the middle.

[0066] At frame 810, the first device 110 receives from the second device 120 via RRC signaling a cell configuration indicating at least one SCell.

[0067] At box 820, the first device 110 receives a first indication from the second device 120 via MAC signaling regarding a first indication that at least one SCell in the SCell has been changed to a PCell.

[0068] In some example embodiments, at least one SCell may include multiple SCells on the same carrier frequency.

[0069] In some example embodiments, one of the multiple SCells can be activated on the carrier frequency.

[0070] In some example embodiments, at least one SCell in a SCell and the previous PCell can be on the same carrier frequency.

[0071] In some example embodiments, at least one SCell and the previous PCell may be on different carrier frequencies.

[0072] In some example embodiments, the first device 110 may receive a second instruction for activating a resource configured to be used after the SCell is changed to the PCell.

[0073] In some example embodiments, in response to receiving a first instruction, the first device 110 may activate resources after the SCell is changed to the PCell, which are configured to be used after the secondary cell is changed to the primary cell.

[0074] In some example embodiments, in response to receiving a first instruction, the first device 110 may activate SCell and change SCell to PCell.

[0075] In some example embodiments, the first device 110 may send a cell activation response to the second device 120 via MAC signaling to indicate that the SCell has been activated and changed to the PCell.

[0076] In some example embodiments, the MAC signaling used to send the first indication may include a cell handover command carried in the MAC CE.

[0077] In some example embodiments, the first device may include a terminal device, and the second device may include a network device.

[0078] In some example embodiments, the apparatus capable of performing method 800 (e.g., Figure 1 The first device 110 may include components for performing the corresponding operations of method 800 and / or any of the one or more example embodiments described herein. This component may be implemented in any suitable form. For example, the component may be implemented in a circuit or software module. The device may be implemented as... Figure 1 The first device 110 or included in Figure 1 In the first device 110.

[0079] Figure 9 A flowchart of an example method 900 implemented at a second device according to some example embodiments of the present disclosure is shown. For the purposes of discussion, [the following will be discussed]. Figure 1 Method 900 is described by the angle of the second device 120 in the middle.

[0080] At frame 910, the second device 120 sends an instruction to the first device 110 via RRC signaling, indicating the cell configuration for at least one SCell of the first device 110.

[0081] At box 920, the second device 120 sends an indication to the first device 110 via MAC signaling regarding a first indication that at least one SCell in the SCell is changed to a PCell for the first device 110.

[0082] In some example embodiments, at least one SCell may include multiple SCells on the same carrier frequency.

[0083] In some example embodiments, one of the multiple SCells can be activated on the carrier frequency.

[0084] In some example embodiments, at least one SCell in the SCell and the previous PCell used for the first device may be on the same carrier frequency.

[0085] In some example embodiments, at least one SCell in the SCell and the previous PCell for the first device may be on different carrier frequencies.

[0086] In some example embodiments, the second device 120 may send a second instruction for activating a resource configured to be used after the SCell is changed to the PCell.

[0087] In some example embodiments, the second device 120 may send a configuration of resources to the first device, the resources being configured to be used after the secondary cell is changed to the primary cell.

[0088] In some example embodiments, the second device 120 may receive a cell activation response from the first device 110 via MAC signaling to indicate that the SCell has been activated and changed to the PCell.

[0089] In some example embodiments, the MAC signaling used to send the first indication may include a cell handover command carried in the MAC control unit (CE).

[0090] In some example embodiments, the first device may include a terminal device, and the second device may include a network device.

[0091] In some example embodiments, the apparatus capable of performing method 800 (e.g., Figure 1 The second device 120 may include components for performing the corresponding operations of method 900 and / or any of the one or more example embodiments described herein. This component may be implemented in any suitable form. For example, the component may be implemented in a circuit or software module. The device may be implemented as... Figure 1 The second device 120 or included in Figure 1 The second device 120 in the middle.

[0092] Figure 10 This is a simplified block diagram of a device 1000 suitable for implementing exemplary embodiments of the present disclosure. The device 1000 can be provided to implement a communication device, for example, as... Figure 1 The first device 110 or the second device 120 shown. As shown, the device 1000 includes one or more processors 1010, one or more memories 1020 coupled to the processors 1010, and one or more communication modules 1040 coupled to the processors 1010.

[0093] Communication module 1040 is used for bidirectional communication. Communication module 1040 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interface can represent any interface necessary for communication with other network elements. In some example embodiments, communication module 1040 may include at least one antenna.

[0094] Processor 1010 can be any type suitable for a local technology network and may include one or more of the following as non-limiting examples: general-purpose computer, special-purpose computer, microprocessor, digital signal processor (DSP), and processor based on a multi-core processor architecture. Device 1000 may have multiple processors, such as application-specific integrated circuit chips that are time-dependent on a clock synchronized with the main processor.

[0095] Memory 1020 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) 1024, electrically programmable read-only memory (EPROM), flash memory, hard disk, miniature optical disc (CD), digital video disc (DVD), optical disc, laser disc, and other magnetic and / or optical storage. Examples of volatile memories include, but are not limited to, random access memory (RAM) 1022 and other volatile memories that will not be maintained during power outages.

[0096] Computer program 1030 includes computer-executable instructions that are executed by an associated processor 1010. The instructions of program 1030 may include instructions for performing operations / actions of some example embodiments of this disclosure. Program 1030 may be stored in memory (e.g., ROM 1024). Processor 1010 can perform any suitable actions and processes by loading program 1030 into RAM 1022.

[0097] The exemplary embodiments of this disclosure can be implemented by program 1030, enabling device 1000 to execute as described in the reference. Figures 1 to 9 Any process discussed in this disclosure. Exemplary embodiments of this disclosure may also be implemented by hardware or a combination of software and hardware.

[0098] In some example embodiments, program 1030 may be tangibly contained in a computer-readable medium, which may be included in device 1000 (such as in memory 1020) or in other storage devices accessible by device 1000. Device 1000 may load program 1030 from the computer-readable medium into RAM 1022 for execution. In some example embodiments, the computer-readable medium may include any type of non-transitory storage medium, such as ROM, EPROM, flash memory, hard disk, CD, DVD, etc. As used herein, the term "non-transitory" is a limitation on the medium itself (i.e., tangible, not tactile), rather than a limitation on the persistence of data storage (e.g., RAM vs. ROM).

[0099] Figure 11 An example of a computer-readable medium 1100 is shown, which may be in the form of a CD, DVD, or other optical storage disc. The computer-readable medium 1100 has a program 1030 stored thereon.

[0100] In general, the various embodiments of this disclosure can be implemented in hardware or dedicated circuitry, software, logic, or any combination thereof. Some aspects can be implemented in hardware, and others can be implemented in firmware or software that can be executed by a controller, microprocessor, or other computing device. Although various aspects of the embodiments of this disclosure are shown and described as block diagrams, flowcharts, or using some other graphical representation, it should be understood that the blocks, apparatuses, systems, techniques, or methods described herein can be implemented in hardware, software, firmware, dedicated circuitry or logic, general-purpose hardware or controllers or other computing devices, or some combination thereof, as non-limiting examples.

[0101] Some exemplary embodiments of this 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 that execute in a device on a target physical or virtual processor, such as those included in a program module, to perform any of the methods described above. Typically, a program module includes routines, programs, libraries, objects, classes, components, data structures, etc., that perform a particular task or implement a particular abstract data type. In various embodiments, the functionality of a program module can be combined or split among program modules as needed. The machine-executable instructions for a program module can execute within a local or distributed device. In a distributed device, the program module can reside on both local and remote storage media.

[0102] Program code used to perform the methods of this 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, when executed by the processor or controller, the program code enables the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may be executed entirely on a machine, partially on a machine, as a stand-alone software package, partially on a machine and partially on a remote machine, or entirely on a remote machine or server.

[0103] In the context of this disclosure, computer program code or related data may be carried by any suitable carrier wave to enable a device, apparatus, or processor to perform the various processes and operations described above. Examples of carrier waves include signals, computer-readable media, etc.

[0104] Computer-readable media can be computer-readable signal media or computer-readable storage media. Computer-readable media can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, or devices, or any suitable combination thereof. More specific examples of computer-readable storage media will include electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fibers, portable optical disc read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0105] Furthermore, although operations are described in a specific order, this should not be construed as requiring such operations to be performed in the specific order shown or sequentially, or requiring all shown operations to achieve the desired result. In some cases, multitasking and parallel processing may be advantageous. Similarly, although several specific implementation details are included in the above discussion, these should not be interpreted as limiting the scope of the exemplary embodiments, but rather as a description of features that may be specific to particular embodiments. Unless explicitly stated otherwise, certain features described in the context of a single embodiment may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated otherwise, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0106] Although this disclosure has been described in language specific to structural features and / or methodological actions, it should be understood that the disclosure as defined in the appended claims is not necessarily limited to the specific features or actions described above. Rather, the specific features and actions described above are disclosed as exemplary forms for implementing the claims.

Claims

1. A first device for communication, comprising: At least one processor; as well as At least one memory, the at least one memory storing instructions, the instructions, when executed by the at least one processor, cause the first device to at least: The second device receives a cell configuration indicating at least one secondary cell via Radio Resource Signalling (RRC) signaling. as well as The second device receives a first indication from the media access control (MAC) signaling that a secondary cell in the at least one secondary cell has been changed to a primary cell.

2. The first apparatus according to claim 1, wherein the at least one secondary cell comprises a plurality of secondary cells on the same carrier frequency.

3. The first apparatus according to claim 2, wherein one of the plurality of secondary cells is activated on the carrier frequency.

4. The first apparatus according to any one of claims 1 to 3, wherein the secondary cell in the at least one secondary cell and the previous primary cell are on the same carrier frequency.

5. The first apparatus according to any one of claims 1 to 3, wherein the secondary cell in the at least one secondary cell and the previous primary cell are on different carrier frequencies.

6. The first device according to any one of claims 1 to 3, wherein the first device is further configured to: Receive a second instruction for activating resources configured to be used after the secondary cell is changed to the primary cell.

7. The first device according to any one of claims 1 to 3, wherein the first device is further configured to: In response to receiving the first instruction, resources are activated after the secondary cell is changed to the primary cell, the resources being configured to be used after the secondary cell is changed to the primary cell.

8. The first device according to any one of claims 1 to 3, wherein the first device is configured such that: In response to receiving the first instruction, the secondary cell is activated; and Change the secondary cell to the primary cell.

9. The first device according to claim 8, wherein the first device is further configured to: A cell activation response is sent to the second device via MAC signaling to indicate that the secondary cell has been activated and changed to the primary cell.

10. The first apparatus according to any one of claims 1 to 3, wherein the MAC signaling for transmitting the first indication includes a cell handover command carried in the MAC control unit (CE).

11. The first device according to any one of claims 1 to 3, wherein the first device includes a terminal device and the second device includes a network device.

12. A second means for communication, comprising: At least one processor; as well as At least one memory, the at least one memory storing instructions, the instructions, when executed by the at least one processor, cause the second device to at least: Sending cell configuration instructions for at least one secondary cell for the first device via RRC signaling; and A first indication is sent to the first device via MAC signaling regarding the change of one of the at least one secondary cell to a primary cell for use by the first device.

13. The second apparatus according to claim 12, wherein the at least one secondary cell comprises a plurality of secondary cells on the same carrier frequency.

14. The second apparatus of claim 13, wherein one of the plurality of secondary cells is activated on the carrier frequency.

15. The second apparatus according to any one of claims 12 to 14, wherein the secondary cell in the at least one secondary cell and the previous primary cell for the first apparatus are on the same carrier frequency.

16. The second apparatus according to any one of claims 12 to 14, wherein the secondary cell in the at least one secondary cell and the previous primary cell for the first apparatus are on different carrier frequencies.

17. The second device according to any one of claims 12 to 14, wherein the second device is further configured to: A second instruction is sent to activate resources configured to be used after the secondary cell is changed to the primary cell.

18. The second device according to any one of claims 12 to 14, wherein the second device is further configured to: The first device is sent with a configuration of resources that are configured to be used after the secondary cell is changed to the primary cell.

19. The second device according to any one of claims 12 to 14, wherein the second device is further configured to: The first device receives a cell activation response via MAC signaling to indicate that the secondary cell has been activated and changed to the primary cell.

20. The second apparatus according to any one of claims 12 to 14, wherein the MAC signaling for transmitting the first indication includes a cell handover command carried in the MAC control unit (CE).

21. The second apparatus according to any one of claims 12 to 14, wherein the first apparatus includes a terminal device and the second apparatus includes a network device.

22. A method of communication, comprising: At the first device. The second device receives a cell configuration indicating at least one secondary cell via Radio Resource Signalling (RRC) signaling. as well as The second device receives a first indication from the media access control (MAC) signaling that a secondary cell in the at least one secondary cell has been changed to a primary cell.

23. A method of communication, comprising: At the second device, Send a cell configuration instruction for at least one secondary cell for the first device via RRC signaling; as well as A first indication is sent to the first device via MAC signaling regarding the change of one of the at least one secondary cell to a primary cell for use by the first device.

24. A first means for communication, comprising: A component for receiving, via Radio Resource Signalling (RRC) signaling, a cell configuration indicating at least one secondary cell from a second device; as well as A component for receiving, via Media Access Control (MAC) signaling, a first indication from the second device that a secondary cell in the at least one secondary cell has been changed to a primary cell.

25. A second means for communication, comprising: Components for sending instructions to a first device via RRC signaling regarding cell configuration for at least one secondary cell of the first device; as well as A component for sending a first indication to the first device via MAC signaling that a secondary cell among the at least one secondary cell has been changed to a primary cell for the first device.

26. A computer-readable medium comprising instructions stored thereon for causing a device to perform at least the method of claim 22 or the method of claim 23.

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