Systems and methods for enhanced timing management of candidate cells in layer 1 / layer 2 mobility

Abstract

Systems and methods for signaling for mobility and timing management of Layer 1 (L1) / Layer 2 (L2) triggers for wireless communications are described herein. In some embodiments, a user equipment (UE) receives a cell handover command as a combination of Downlink Control Information (DCI) and Medium Access Control Control Elements (MAC-CEs) corresponding to the DCI. In some embodiments, the same transmission configuration indicator (TCI) state ID set is used for all candidate cells of a sub-candidate cell group (CCG) of a configured CCG. In some embodiments, the MAC-CE is used to notify the UE of timing advance (TA) information using TAG-specific physical cell identification (PCI) indices for candidate cells of a timing advance group (TAG), the TAG-specific physical cell identification (PCI) indices corresponding to a complete PCI for those candidate cells.

Description

Technical Field

[0001] The present application generally relates to wireless communication systems, including wireless communication systems that support layer 1 (L1) / layer 2 (L2) triggered mobility and timing management. Background Art

[0002] Wireless mobile communication technologies use various standards and protocols to transmit data between base stations and wireless communication devices. For example, wireless communication system standards and protocols may include the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) (e.g., 4G), 3GPP New Radio (NR) (e.g., 5G), and the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard for wireless local area networks (WLANs) (commonly referred to within industry organizations as IEEE). ).

[0003] As envisioned by 3GPP, different wireless communication system standards and protocols may use various radio access networks (RANs) to facilitate communication between base stations of the RAN (which may also be often referred to as RAN nodes, network nodes, or simply nodes) and wireless communication devices called user equipment (UEs). 3GPP RANs may include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rates for GSM Evolution (EDGE) RAN (GERAN), Universal Terrestrial Radio Access Network (UTRAN), Evolved Universal Terrestrial Radio Access Network (E-UTRAN), and / or Next Generation Radio Access Network (NG-RAN).

[0004] Each RAN can use one or more radio access technologies (RATs) to perform communications between base stations and UEs. For example, GERAN implements GSM and / or EDGE RATs, UTRAN implements Universal Mobile Telecommunications System (UMTS) RATs or other 3GPP RATs, E-UTRAN implements LTE RATs (sometimes referred to as LTE), and NG-RAN implements NR RATs (sometimes referred to herein as 5G RATs, 5G NR RATs, or simply NR). In some deployments, E-UTRAN may also implement NR RATs. In some deployments, NG-RAN may also implement LTE RATs.

[0005] The base stations used by the RAN may correspond to the RAN. An example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (often also denoted as an evolved Node B, enhanced Node B, eNodeB, or eNB). An example of an NG-RAN base station is a Next Generation Node B (sometimes also referred to as a gNode B or gNB).

[0006] The RAN provides communication services with external entities through its connection to the Core Network (CN). For example, E-UTRAN may utilize the Evolved Packet Core (EPC), while NG-RAN may utilize the 5G Core Network (5GC).

[0007] The frequency bands of 5G NR can be divided into two or more different frequency ranges. For example, frequency range 1 (FR1) may include frequency bands operating at frequencies below 6 gigahertz (GHz), some of which may be used by previous standards and may potentially be expanded to cover new spectrum products from 410 megahertz (MHz) to 7125 MHz. Frequency range 2 (FR2) may include frequency bands from 24.25 GHz to 52.6 GHz. Note that in some systems, FR2 may also include frequency bands from 52.6 GHz to 71 GHz (or higher). The frequency bands in the millimeter wave (mmWave) range of FR2 may have smaller coverage than the frequency bands in FR1 but potentially higher available bandwidth. Technicians will recognize that these frequency ranges, provided by way of example, may change over time or across regions. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] To easily identify the discussion of any particular element or action, the most significant digit(s) in a reference number refers to the drawing number that first introduces that element.

[0009] Figure 1 The MAC-CE format used as part of the LTM cell handover command according to the embodiments herein is illustrated.

[0010] Figure 2 A table showing the definition of values ​​that may be found in the TA Usage field of the MAC-CE format according to embodiments herein is illustrated.

[0011] Figure 3 A diagram illustrating an example of implementing a cell switching command for LTM using MAC-CE and subsequent DCI according to an embodiment of this document.

[0012] Figure 4 A diagram illustrating beam information indication for candidate cells in a target CCG under a first option according to an embodiment of this document is illustrated.

[0013] Figure 5 A diagram illustrating beam information indication for candidate cells in a target CCG under the second option according to an embodiment of this document is illustrated.

[0014] Figure 6A An example of RAR MAC-CE for LTM procedure according to embodiments of this document is illustrated.

[0015] Figure 6B An example of TAC MAC-CE for LTM procedure according to the embodiments of this document is illustrated.

[0016] Figure 7 An example of a single shared TAG used between candidate cells in LTM operation according to the methods described herein is illustrated.

[0017] Figure 8 A method of a UE according to the embodiments of this document is illustrated.

[0018] Figure 9 A method of RAN according to embodiments of this document is illustrated.

[0019] Figure 10 A method of a UE according to the embodiments of this document is illustrated.

[0020] Figure 11 A method of RAN according to embodiments of this document is illustrated.

[0021] Figure 12 A method of a UE according to the embodiments of this document is illustrated.

[0022] Figure 13 A method of RAN according to embodiments of this document is illustrated.

[0023] Figure 14 A method of a UE according to the embodiments of this document is illustrated.

[0024] Figure 15 A method of RAN according to embodiments of this document is illustrated.

[0025] Figure 16 A method of a UE according to the embodiments of this document is illustrated.

[0026] Figure 17 A method of RAN according to embodiments of this document is illustrated.

[0027] Figure 18 A method of a UE according to the embodiments of this document is illustrated.

[0028] Figure 19 A method of RAN according to embodiments of this document is illustrated.

[0029] Figure 20 An example architecture of a wireless communication system according to embodiments disclosed herein is illustrated.

[0030] Figure 21 A system for performing signaling between a wireless device and a network device according to embodiments disclosed herein is illustrated. DETAILED DESCRIPTION

[0031] Various embodiments are described with respect to a UE. However, reference to a UE is provided for illustrative purposes only. The example embodiments may be used with any electronic component that can establish a connection with a network and is configured with hardware, software, and / or firmware for exchanging information and data with the network. Therefore, a UE as described herein is used to represent any suitable electronic component.

[0032] Wireless communication services (e.g., mobility services) designed for low latency and high reliability performance (e.g., ultra-reliable and low-latency communication (URLLC)) are emerging. While some wireless communication standards (e.g., some 5G standards) have been designed to address these use cases, further evolution of these standards continues with the goal of enhancing mobility robustness for various challenging scenarios.

[0033] In some cases, it may be beneficial to implement Layer 1 (L1) enhancements related to inter-cell beam management, including, for example, aspects of L1 measurement and reporting and / or beam indication. However, in some environments, the exact nature of the information / content provided by the cell handover command for L1 / Layer 2 (L2) mobility (LTM) scenarios and the corresponding parameters may be undefined for various use cases.

[0034] Furthermore, for the case of L1 / L2 inter-cell mobility, it is possible that the UE is first configured with candidate target cells for L1 / L2 mobility, and then subsequently switches to these candidate target cells in a simultaneous manner during the L1 / L2 mobility serving cell change. In this environment, it may be beneficial to indicate beam information for each of the candidate cells in a manner that minimizes or reduces signaling overhead.

[0035] Finally, in the case of timing advance (TA) management in LTM operation, various improvements are possible. For example, a wireless communication system may be configured to support obtaining TA information (e.g., TA offset values) for one or more candidate cells prior to receiving a cell handover command according to the LTM procedure. It is noted that in such cases, it may be typical for a large number of candidate cells to be configured for L1 measurement reporting (so that the network can select the best cell for handover). In such cases, assigning a timing advance group (TAG) for each candidate cell would result in the use of a significantly increased number of TAG numbers (and associated signaling) and may not be preferred. Therefore, the discussion herein relates to the development of TA management schemes for LTM that can be used to maintain TA offset values ​​associated with non-serving cells of a UE and with the goal of minimizing regulatory impact and / or signaling overhead.

[0036] Implementation plan for cell switching command structure

[0037] According to certain aspects of the present disclosure, before a cell handover command is received, the following mechanism may be considered for providing beam information for a target cell in LTM operation when a Transmit Configuration Indicator (TCI) status list has been pre-configured for a special cell (SpCell) by radio resource control (RRC) signaling.

[0038] In a first alternative for the construction of a cell handover command, the combination of scheduling downlink control information (DCI) and the corresponding medium access control element (MAC-CE) can be (combined) considered as an LTM cell handover command. In such a case, the corresponding MAC-CE format for the MAC-CE can be used. For example, Figure 1 Illustrated is a MAC-CE format 100 used as part of an LTM cell handover command according to embodiments herein.A discussion of the fields that may be used as part of the MAC-CE format 100 now proceeds as follows.

[0039] MAC-CE format 100 may include a non-serving cell ID field 102 indicating the identity of a target non-serving cell ID. In other words, this value of non-serving cell ID field 102 identifies to the UE the non-serving cell to which the rest of the information in MAC-CE format 100 applies.

[0040] MAC-CE format 100 may also include an uplink (UL) bandwidth part (BWP) identifier (ID) field 104 and a downlink (DL) BWP ID field 106. These fields identify the target frequency resources corresponding to the identified non-serving cell in the UL and DL contexts, respectively. Note that in some designs, a single DL BWP and UL BWP may be preconfigured and used during the LTM process. In such cases, UL BWP ID field 104 and / or DL ​​BWP ID field 106 may be optional.

[0041] Now let's discuss the MAC-CE content related to the TCI status of the target non-serving cell. The MAC-CE format 100 may also include one or more P i Field 108, where P i Each of the fields 108 corresponds to a TCI code point that may be received in a scheduling DCI corresponding to the MAC-CE format 100. In the MAC-CE format 100, there are eight P i Field 108, thereby anticipating the possibility that the received TCI code point may take one of eight possible values. iEach of the fields 108 may indicate, for a corresponding one of its TCI code points, whether the TCI code point is associated with one or both of the TCI state ID fields 112. This may be used, for example, in situations where the non-serving cell of the MAC-CE format 100 is understood to operate in the context of a separate TCI state mode. As indicated, P i Field 108 may be a 1-bit field.

[0042] The MAC-CE format 100 may also include one or more D / U fields 110 and one or more corresponding TCI state ID fields 112. The D / U field 110 indicates, for a corresponding one of the TCI state ID fields 112 (e.g., a TCI state ID field in the same octet as the D / U field), whether the TCI state ID indicated in the TCI state ID field is understood to be associated with a DL TCI state or a UL TCI state of a TCI state list for a non-serving cell corresponding to the MAC-CE format 100. As illustrated, the D / U field 110 may be a 1-bit field.

[0043] The TCI state ID field 112 indicates the selection of a TCI state index / activated TCI state selected from a TCI state list corresponding to a non-serving cell (e.g., which may have been previously provided to the UE by RRC signaling). In other words, these TCI state indexes are configured to identify a specific TCI state in the TCI state list associated with the non-serving cell in the MAC-CE format 100.

[0044] In some embodiments, it is possible that the activated DL / UL TCI state pair is selected by a TCI codepoint in a TCI field in a scheduling DCI format that schedules a (e.g., later) MAC-CE physical downlink shared channel (PDSCH) transmission using MAC-CE format 100. This TCI state pair may then be used for DL ​​reception and UL transmission during (and after) the LTM procedure with respect to a non-serving cell (e.g., during handover to a non-serving cell). Figure 1 An example of such selection of TCI state pairs has been illustrated in .

[0045] The MAC-CE content related to UL TA information is now discussed. The MAC-CE format 100 may further include a TA usage field 114 and a TA field 116. The TA usage field 114 may indicate the usage of the TA field 116.

[0046] Figure 21. Table 200 is illustrated showing definitions of values ​​that may be found in the TA Usage field 114 of the MAC-CE format 100 according to embodiments herein. Note that in embodiments such as Figure 1 and Figure 2 In those embodiments contemplated in the , TA Usage field 114 may accordingly use two bits, where the TA Usage field may define one of four possible uses of the TA field 116. Furthermore, it is contemplated that the TA field 116 may be 12 bits.

[0047] In the first case 202, the TA usage field 114 may take the value "00". This may indicate to the UE that the UE will perform UL transmission during handover to a non-serving cell without using any TA offset value. In this case, no specific use of the TA field 116 may be understood.

[0048] In the second case 204, the TA usage field 114 may take the value "01". This may indicate to the UE that the UE will use the currently (e.g., previously existing) configured / understood TA offset value for the non-serving cell to perform UL transmissions during handover to the non-serving cell. In this case, no specific use of the TA field 116 may be understood.

[0049] In the third case 206, the TA usage field 114 may take on a value of "10". This may indicate to the UE that the bits (e.g., 12 bits) of the TA field 116 are to be understood as indicating a specified (e.g., absolute) TA offset value to be used by the UE for UL transmissions during communications with a non-serving cell (e.g., handover to a non-serving cell). In such cases, the network accordingly provides the specified TA offset value in the TA field 116.

[0050] In a fourth case 208, the TA usage field 114 may take a value of "11". This may indicate to the UE that the bits of the TA field 116 provide configuration information regarding a contention-free random access (CFRA) procedure to be performed by the UE with a non-serving cell to determine a TA offset value to be used for communication with the non-serving cell. In this case, the network may provide a synchronization signal block (SSB) index in a first portion of the TA field 116 (e.g., in the six most significant bits (MSBs) of the TA field 116) and a physical random access channel (PRACH) index in a second portion of the TA field 116 (e.g., in the six least significant bits (LSBs) of the TA field 116).

[0051] The SSB index may be used to select multiple PRACH resources for the CFRA process and determine the spatial relationship of the PRACH transmission for the CFRA process. In addition, the PRACH index may be used to select a PRACH resource from multiple PRACH resources for PRACH transmission.

[0052] Subsequently, as part of a CFRA procedure occurring between the UE and the non-serving cell configured based on this information, the UE determines a TA offset value that can be used by the UE for UL transmissions during communications with the non-serving cell (e.g., handover to the non-serving cell).

[0053] return Figure 1 , MAC-CE format 100 may also include a timer field 118. This timer field 118 may carry a timer value for a timer that is started at the UE upon receiving the MAC-CE of MAC-CE format 100 as part of a cell handover command and is disabled / cancelled when the UE successfully hands over to a non-serving cell. In the alternative case where this timer expires instead, the expiration may trigger the UE to initiate an RRC reestablishment procedure with a serving cell (e.g., prior to attempting a handover) (or fall back to the serving cell) to continue operations. Therefore, it can be understood that the timer field 118 provides a timer value for determining whether a handover to a non-serving cell has failed.

[0054] The MAC-CE format 100 may also include a UL grant field 120. The UL grant field 120 may provide resource allocation for the UE on a non-serving cell. In other words, the UL grant field 120 may identify resources that may be used by the UE for UL transmission on a non-serving cell.

[0055] In alternative embodiments to those using scheduling DCI and MAC-CE format 100, it is possible that the MAC-CE contains only a single pair of DL / UL TCI states or a single reference signal (RS) index to be used for LTM operation. This configuration may not use scheduling DCI to specify a TCI state pair, because in such cases the MAC-CE contains only one resolvable / usable TCI state pair / single RS index to use with the other configuration parameters provided.

[0056] In a second alternative for the construction of a cell handover command, the combination of the MAC-CE and the subsequent DCI may be considered (combined) as an LTM cell handover command. Figure 3 Diagram 300 illustrates one example of using MAC-CE and subsequent DCI to implement a cell switching command for LTM according to embodiments herein.

[0057] Under the second alternative, a MAC-CE may be introduced to provide mobility trigger information about multiple candidate cells. This MAC-CE may be received at the UE on a PDSCH scheduled according to a scheduling DCI previously received at the UE (this scheduling DCI is not received at the UE). Figure 3 One or more information items in this MAC-CE may be as shown in FIG. Figure 1 As described in the MAC-CE format 100.

[0058] Subsequently, a separate DCI (e.g., temporally following the MAC-CE) may be used to trigger an LTM cell handover operation with the selected candidate cell. This DCI may select a TCI state pair (or DL ​​RS) from the activated TCI state / DL RS associated with the selected candidate cell as activated by the MAC-CE, and may also include the physical cell identity (PCI) or virtual ID of the selected candidate cell. This information enables the UE to perform a handover to the identified candidate serving cell using the selected TCI state pair.

[0059] This DCI may also inform the UE of the (e.g., absolute) TA offset value to be used for UL communications with the selected candidate cell. In some embodiments, the TA offset value associated with the selected candidate cell may be provided directly by the DCI by reusing a reserved bit (e.g., when using fallback DCI 1_0 format) or by adding a new field to the DCI (e.g., when using DCI format 1_1).

[0060] Figure 3 Assume a scenario where UE 302 is performing a handover from source cell 304 and there are two candidate cells: a first candidate cell 306 and a second candidate cell 308, from which the UE may select a candidate cell to perform the handover.

[0061] exist Figure 3 In the illustrated example embodiment of , one or more information items found in MAC-CE format 100 may be delivered for each of the first candidate cell 306 and the second candidate cell 308 in respective sub-blocks of a MAC-CE 310, which is received at the UE at T1 as indicated. A first sub-block 312 of the MAC-CE 310 corresponds to the first candidate cell 306 and indicates (e.g., in a manner as described with respect to the MAC-CE format 100) four activated TCI states for the first candidate cell 306. Additionally, a second sub-block 314 of the MAC-CE 310 corresponds to the second candidate cell 308 and indicates (e.g., also in a manner as described with respect to the MAC-CE format 100) three activated TCI states for the second candidate cell 308.

[0062] Subsequently, at time T2, DCI 316 (e.g., in a separate DCI format) is used to trigger an LTM process to the first candidate cell 306 (e.g., by identifying the PCI of the first candidate cell 306), and a TCI state pair (e.g., TCI#2 and TCI#3, as shown in FIG1 ) is selected from the four activated TCIs for the first candidate cell 306. Figure 3 The selected TCI state pair may be used for DL ​​reception and UL transmission. Note that the DCI 316 may also provide a (eg, absolute) TA offset value for use by the UE 302 in UL communication with the first candidate cell 306.

[0063] Implementation scheme for beam indication for candidate cells within a candidate cell group

[0064] In some embodiments, a list of candidate cell groups (CCGs) may be provided to the UE via RRC signaling prior to a cell handover command, where each CCG includes at least one SpCell and one or more secondary cells (SCells) as candidate cells. In such cases, various methods may be considered to efficiently indicate beam information for candidate cells in the CCG using a reduced amount of corresponding signaling.

[0065] As a first step, the network can configure the candidate cells of a CCG into different sub-CCGs. This can be done using, for example, an RRC message from the network to the UE.

[0066] Then, a pair of options may be considered to simultaneously update the TCI status for all candidate cells within a sub-CCG.

[0067] The first such option uses a shared TCI state ID update for all candidate cells in a sub-CCG. Under the first option, the network configures / has configured a separate TCI state list for each candidate cell in the sub-CCG (e.g., via RRC signaling). Subsequently, whenever a TCI state ID set is received in a MAC-CE for any candidate cell in the sub-CCG, the same set of TCI state IDs is activated for all candidates within the sub-CCG (e.g., each candidate cell uses these (same) TCI state IDs to identify the activated TCI state from its corresponding TCI state list). The first option enables the network to configure the use of different TCI states with different candidate cells using a single set of TCI state IDs (reducing signaling overhead relative to the case where a separate set of TCI state IDs is signaled for each candidate cell in the sub-CCG).

[0068] Figure 4 A diagram 400 illustrating beam information indication for candidate cells in a target CCG under a first option according to embodiments herein is illustrated. Figure 4 Assume the case of handover 402 of a SpCell from a serving cell 404 to a CCG 406, as illustrated. Figure 4 Six candidate cells in a CCG are illustrated, and these six candidate cells have been divided into a first sub-CCG 408 and a second sub-CCG 410 (each having three candidate cells). The network can notify the UE of this division in the configuration information provided by the network to the UE. It should be noted that this arrangement (e.g., the total number of candidate cells in the CCG, the number of sub-CCGs, and the specific division of candidate cells into sub-CCGs / the number of candidate cells in each sub-CCG) is given by way of example and not by way of limitation.

[0069] exist Figure 4 In the example, a separate TCI state list has been configured for each candidate cell independently. Note that in this case, the TCI state list for each candidate cell can be arbitrary with respect to the LTM cell switching scheme (as illustrated).

[0070] Subsequently, a MAC-CE of an LTM cell handover command may be received at the UE. This MAC-CE may (directly) indicate one or more TCI state IDs of candidate cells for the CCG. Figure 4 In this case, it is possible that the received MAC-CE corresponds to the SpCell (but this is not required). In this case, the TCI state ID directly activated in the MAC-CE for the SpCell also applies to other candidate cells in the sub-CCG of the SpCell (other candidate cells in the first sub-CCG 408). Therefore, the UE uses those same TCI state IDs to activate the TCI states for Scell#1 and Scell#2 based on applying those same TCI state IDs to the corresponding TCI state lists for each of Scell#1 and Scell#2.

[0071] It will be further understood that if a second MAC-CE is received identifying a TCI state ID for use with candidate cells of a second sub-CCG (e.g., for Scell#3 on the second sub-CCG 410), a similar process will be used to determine the TCI state for each of the candidate cells in the second sub-CCG using those same TCI state IDs with respect to the separate TCI state lists for each candidate cell in that sub-CCG (e.g., those same TCI state IDs will be applied with separate TCI state lists for Scell#3, Scell#4, and Scell#5).

[0072] Under the second option, unlike the first option, a single TCI state list for one candidate cell per sub-CCG is used. These TCI state lists can be configured at the UE via RRC signaling. Subsequently, whenever a MAC-CE (e.g., corresponding to an LTM cell handover command) for a candidate cell configured with a TCI state list is indicated with a TCI state ID, the activated TCI state selected from the TCI state list based on these TCI state IDs is applied to all candidate cells in the same sub-CCG. This further reduces network signaling compared to the case of the first option, as each sub-CCG needs to be configured with only one TCI state list (as opposed to configuring a separate TCI state list for each candidate cell of the sub-CCG).

[0073] Figure 5 A diagram 500 illustrating beam information indication for candidate cells in a target CCG under the second option according to embodiments herein is illustrated. Figure 5 Assume the case of handover 502 of a SpCell from a serving cell 504 to a CCG 506, as illustrated. Figure 5 Six candidate cells in a CCG are illustrated, and these six candidate cells have been divided into a first sub-CCG 508 and a second sub-CCG 510 (each having three candidate cells). The network can inform the UE of this division in the configuration information provided by the network to the UE. It should be noted that this arrangement (e.g., the total number of candidate cells, the number of sub-CCGs, and the specific division of candidate cells into sub-CCGs / the number of candidate cells in each sub-CCG) is given by way of example and not by way of limitation.

[0074] exist Figure 4 In FIG. 5 , separate TCI state lists have been independently configured for one cell (SpCell) of the first sub-CCG 508 and one cell (Scell#3) of the second sub-CCG 510. Note that the TCI state lists used for these cells can be arbitrary with respect to the LTM cell handover scheme (as illustrated). Note also that in other embodiments, a TCI state list can be configured for another cell (e.g., Scell#1 or Scell#2) of the first sub-CCG 508 instead.

[0075] Subsequently, a MAC-CE of an LTM cell handover command may be received at the UE. This MAC-CE may (directly) indicate one or more TCI state IDs for one of the candidate cells with the configured TCI state list. Figure 4In this case, it is possible that the received MAC-CE corresponds to the SpCell (but this is not required, as the MAC-CE in this context may alternatively correspond to Scell#3). In this case, the UE uses the indicated TCI state ID to activate the TCI state for the SpCell based on the TCI state list for the SpCell. Furthermore, because Scell#1 and Scell#2 are in the same sub-CCG as the SpCell (the first sub-CCG 508), these same TCI states are (also) understood to be activated for Scell#1 and Scell#2.

[0076] In such embodiments, it will be further understood that if a second MAC-CE is received identifying a TCI state ID for use with a cell of a second sub-CCG (e.g., second sub-CCG 510), which cell is configured with a TCI state list (e.g., for Scell#3) to activate TCI states on that list, then any such activated TCI state will (also) be considered active for the other cells of the second sub-CCG (e.g., each of Scell#3, Scell#4, and Scell#5).

[0077] Implementation of enhanced timing management for candidate cells in LTM

[0078] According to certain aspects of the present disclosure, various methods for managing UL TA offset values ​​for non-serving cells (eg, on the same frequency layer) may be introduced.

[0079] First, a configuration message (e.g., an RRC configuration message) from the network to the UE may identify that multiple candidate cells on a shared frequency layer share a single TAG. The TAG is identified by a dedicated TAG-ID in the configuration message.

[0080] Each candidate cell in the candidate cell group may correspond to a PCI index known to the UE that corresponds to the (full) PCI for the same candidate cell. These PCI indexes may be communicated from the network to the UE in configuration signaling. For example, in some cases, one or more PCI indexes for one or more of the candidate cells in the TAG may be provided in the same configuration message that indicates the TAG-ID for the TAG. Alternatively, an additional configuration message may be used to provide the UE with PCI indexes for one or more of the cells in the TAG. It is also envisioned that configuration signaling may also be used to update the PCI indexes for the candidate cells in a similar manner.

[0081] Subsequently, a MAC-CE may be transmitted between the network and the UE to provide an initial TA offset value or an update of the TA offset value for / for one of the candidate cells in the candidate cell group. The MAC-CE may indicate the TAG-ID for the cell group and (in addition) the PCI index corresponding to one of the cells in the cell group.

[0082] The MAC-CE used can be identified by a medium access control (MAC) subheader with a dedicated logical channel ID (LCID), which corresponds to one of the random access response (RAR) MAC-CE and the TA command (TAC) MAC-CE (each of which can have a fixed size).

[0083] Figure 6A An example of a RAR MAC-CE 602 for an LTM procedure according to embodiments herein is illustrated. Figure 6B An example of a TAC MAC-CE 604 for an LTM procedure according to embodiments herein is illustrated. The fields that may appear in these MAC-CEs will now be discussed.

[0084] The RAR MAC-CE 602 and / or the TAC MAC-CE 604 may implement a TAG-ID field 606. The TAG ID field 606 indicates a TAG-ID for the TAG to which the MAC-CE applies.

[0085] The RAR MAC-CE 602 and / or the TAC MAC-CE 604 may implement a PCI index field 608. The PCI index field 608 indicates the PCI index for a specific non-serving cell within the TAG to which the MAC-CE applies. The UE may be aware of the correspondence between the (full) PCI of the candidate cell and the PCI index for the candidate cell based on previously received configuration signaling (e.g., RRC signaling).

[0086] The RAR MAC-CE 602 and / or the TAC MAC-CE 604 may implement a TAC field 610. The TAC field 610 may be used by the UE to determine the TA offset value for a specific non-serving cell within the TAG to which the MAC-CE applies. Figure 6A In the example of , RAR MAC-CE 602 uses an 11-bit wide TAC field 610, while Figure 6B, the TAC MAC-CE 604 uses a 6-bit wide TAC field 610. This may correspond to different usages for each of the RAR MAC-CE 602 and the TAC MAC-CE 604. For example, it may be that the RAR MAC-CE 602 is used to deliver an absolute TA offset value in its TAC field 610 (requiring relatively more bits), while the TAC MAC-CE 604 is used to deliver a TA offset adjustment value (to be applied together with the existing TA offset value to determine the adjusted TA offset value) in its TAC field 610 (requiring relatively fewer bits).

[0087] Upon receiving the RAR MAC-CE 602 or the TAC MAC-CE 604, the UE can identify the candidate cell to which the RAR MAC-CE 602 or the TAC MAC-CE 604 applies by applying the known correspondence between the TAG-ID for the TAG represented in the TAG-ID field 606 and the PCI index from the PCI index field 608 and the (complete) PCI for the non-serving cell within the TAG corresponding to the PCI index. The TAC of the TAC field 610 can then be applied to the identified candidate cell (e.g., an appropriate TA offset value can be established and / or updated for the identified candidate cell based on the TAC of the TAC field 610).

[0088] Figure 7 Illustrated is an example of a single shared TAG 702 used between candidate cells in LTM operations according to the methods described herein. Figure 7 The example assumes that the UE is currently served on a cell with (full) PCI #0, and there are 6 non-serving cells with (full) PCIs #10, #21, #13, #34, #65 and #66, all on the same frequency layer.

[0089] First, the network may assign TAG=6 for this frequency layer (as illustrated) so that this TAG is shared by all illustrated non-serving cells for TA management purposes. Furthermore, it is possible that the PCI index value 704 has been configured (e.g., via RRC signaling) for each (complete) PCI 706 of the non-serving cell corresponding to the TAG, as shown. Figure 7 Described in.

[0090] The network may then trigger a physical downlink control channel (PDCCH) ordered CFRA procedure and use, for example, a RAR MAC-CE and / or a TAC MAC-CE to provide a TA for one or more of the non-serving cells. At the UE side, a TA list 708 is created to store any such received / updated TA values ​​for different non-serving cells with respect to these MAC-CEs (e.g., in increasing order of PCI index values, as illustrated). This list may be associated with TAG=6 (e.g., based on the TAG-ID field of the received RAR MAC-CE and / or TAC MAC-CE).

[0091] Later, when the UE receives a cell handover command indicating LTM toward a cell of PCI#66 in TAG=6 (e.g., in a second MAC-CE), the UE identifies the TA value to be used for communication (e.g., handover) with PCI#66 from the TA list 708 (for TAG=6) based on the known correspondence between PCI#66 used in the second MAC-CE and the first PCI index used in the first MAC-CE to generate / update the corresponding entry in the TA list 708.

[0092] It should be noted that with this method, there is no need to include the TA value or TAG-ID in the (second) cell handover command MAC-CE, thus improving the signaling efficiency within the system.

[0093] Finally, it is noted that while the discussion herein relates to delivering a TAC within a candidate cell group (e.g., in the context of a TA offset value for communication by a UE with one of the candidate cells), this is provided by way of example and not by way of limitation. It will be appreciated that the described mechanism using a mapping between a PCI index and a (full) PCI can be used for MAC-CE delivery of information other than TA information / handover information, e.g., between multiple cells of a TAG.

[0094] Figure 8 A method 800 of a UE according to embodiments herein is illustrated. The method 800 includes receiving 802 a DCI including a TCI field having a TCI code point and scheduling information for a PDSCH from a network.

[0095] The method 800 further includes receiving 804 a MAC-CE of a PDSCH from the network, the MAC-CE including an indication for the UE to perform handover and a plurality of TCI state IDs of activated TCI states of a target non-serving cell for the handover.

[0096] The method 800 further includes identifying 806 a TCI state pair from the activated TCI states by applying a TCI code point with a plurality of TCI state IDs.

[0097] The method 800 also includes performing 808 a handover to a target non-serving cell, the handover including communicating with the target non-serving cell using the TCI state pair.

[0098] In some implementations of method 800, the MAC-CE also includes a cell ID for the target non-serving cell.

[0099] In some embodiments of method 800, the MAC-CE also includes a UL BWP ID and a DL BWP ID for the target non-serving cell.

[0100] In some embodiments of the method 800 , the MAC-CE further includes bits indicating that the TCI code point is used to identify two TCI state IDs among the plurality of TCI state IDs.

[0101] In some embodiments of method 800, the MAC-CE further includes a first value in the first 1-bit field indicating that the first TCI state of the TCI state pair is the UL TCI state and a second value in the second 1-bit field indicating that the second TCI state of the TCI state pair is the DLTCI state.

[0102] In some embodiments of method 800, the MAC-CE also includes a TA usage value in the TA usage field, the TA usage value indicating that the TA field in the MAC-CE is retained and the UE will communicate with the target non-serving cell without using the TA offset value, and wherein the UE performs UL transmission during handover to the target non-serving cell without using the TA offset value.

[0103] In some embodiments of method 800, the MAC-CE also includes a TA usage value in the TA usage field, the TA usage value indicating that the TA field in the MAC-CE is retained and the UE will communicate with the target non-serving cell based on the currently configured TA offset value for the target non-serving cell, and wherein the UE uses the currently configured TA offset value for the target non-serving cell to perform UL transmission during handover to the target non-serving cell.

[0104] In some embodiments of method 800, the MAC-CE further includes: a TA usage value in a TA usage field, the TA usage value indicating that the UE will use a specified TA offset value to communicate with the target non-serving cell, the specified TA offset value is in the TA field, and wherein the UE uses the specified TA offset value to perform UL transmission during handover to the target non-serving cell.

[0105] In some embodiments of method 800, the MAC-CE further includes: a TA usage value in a TA usage field, the TA usage value indicating that the UE is to perform a CFRA process with the target non-serving cell to determine a TA offset value to be used for communicating with the target non-serving cell; and a TA field, the TA field including: an SSB index in a first set of bits of the TA field, an SSB index of a plurality of PRACH resources and a spatial relationship that can be used by the UE as part of the CFRA process for selecting PRACH transmission, and a PRACH index in a second set of bits of the TA field, the PRACH index that can be used by the UE as part of the CFRA process to select a PRACH resource from a plurality of PRACH resources, wherein the UE performs handover to the target non-serving cell using the TA offset value determined by performing the CFRA process.

[0106] In some embodiments of method 800, the MAC-CE further includes a timer value identifying a timer used to determine whether handover to the target non-serving cell has failed.

[0107] In some embodiments of method 800, the MAC-CE also includes a UL grant identifying resources that can be used by the UE for UL transmission on the target non-serving cell.

[0108] Figure 9 A method 900 of a RAN according to embodiments herein is illustrated. The method 900 includes receiving 902 an L1 measurement report from a UE.

[0109] The method 900 also includes identifying 904 a target non-serving cell for handover to be performed by the UE based on the L1 measurement report.

[0110] The method 900 also includes transmitting 906 to the UE a DCI including a TCI field having a TCI codepoint and scheduling information for the PDSCH.

[0111] The method 900 also includes transmitting 908 a MAC-CE on a PDSCH to the UE, the MAC-CE including an indication for the UE to perform a handover and a plurality of TCI state IDs for the activated TCI states of the target non-serving cell, wherein the plurality of TCI state IDs are configured for use with the TCI code point to identify a TCI state pair from the activated TCI states for the handover.

[0112] The method 900 also includes communicating 910 with the UE on the target non-serving cell to implement the handover to the target non-serving cell.

[0113] In some implementations of method 900, the MAC-CE also includes a cell ID for the target non-serving cell.

[0114] In some embodiments of method 900, the MAC-CE also includes a UL BWP ID and a DL BWP ID for the target non-serving cell.

[0115] In some embodiments of the method 900 , the MAC-CE further includes bits indicating that the TCI code point is used to identify two TCI state IDs among the plurality of TCI state IDs.

[0116] In some embodiments of method 900, the MAC-CE further includes a first value in the first 1-bit field indicating that the first TCI state of the TCI state pair is the UL TCI state and a second value in the second 1-bit field indicating that the second TCI state of the TCI state pair is the DLTCI state.

[0117] In some embodiments of method 900, the MAC-CE further includes a TA usage value in the TA usage field, the TA usage value indicating that the TA field in the MAC-CE is reserved and the UE will communicate with the target non-serving cell without using the TA offset value.

[0118] In some embodiments of method 900, the MAC-CE also includes a TA usage value in the TA usage field, which indicates that the TA field in the MAC-CE is retained and the UE will communicate with the target non-serving cell based on the currently configured TA offset value for the target non-serving cell.

[0119] In some embodiments of method 900, the MAC-CE further includes: a TA usage value in a TA usage field, the TA usage value indicating that the UE will use a specified TA offset value to communicate with the target non-serving cell, and the specified TA offset value is in the TA field.

[0120] In some embodiments of method 900, the MAC-CE also includes: a TA usage value in a TA usage field, the TA usage value indicating that the UE is to perform a CFRA process with the target non-serving cell to determine a TA offset value to be used for communicating with the target non-serving cell; and a TA field, the TA field including: an SSB index in a first set of bits of the TA field, an SSB index that can be used by the UE as part of the CFRA process to select multiple PRACH resources and spatial relationships for PRACH transmission, and a PRACH index in a second set of bits of the TA field, the PRACH index can be used by the UE as part of the CFRA process to select a PRACH resource from multiple PRACH resources.

[0121] In some embodiments of method 900, the MAC-CE further includes a timer value identifying a timer used to determine whether handover to the target non-serving cell has failed.

[0122] In some embodiments of method 900, the MAC-CE also includes a UL grant identifying resources that can be used by the UE for UL transmissions on the target non-serving cell.

[0123] Figure 10 A method 1000 of a UE according to embodiments herein is illustrated. The method 1000 includes receiving 1002 a first DCI including scheduling information for a PDSCH from a network.

[0124] The method 1000 also includes receiving 1004 a MAC-CE for a PDSCH from the network, the MAC-CE including a first plurality of TCI state IDs for a first activated TCI state of a first candidate serving cell and a second plurality of TCI state IDs for a second activated TCI state of a second candidate serving cell.

[0125] The method 1000 also includes receiving 1006 from the network a second DCI including the TCI code point and the physical cell ID of the first candidate serving cell.

[0126] The method 1000 also includes determining 1008 to identify a TCI state pair using a first plurality of TCI state IDs for the first candidate serving cell based on receiving the first physical cell ID of the first candidate serving cell in the second DCI.

[0127] The method 1000 further includes identifying 1010 a TCI state pair from the first activated TCI state for the first candidate serving cell by applying TCI code points having a first plurality of TCI state IDs.

[0128] The method 1000 also includes performing 1012 a handover to a first candidate serving cell, the handover including communicating with the first candidate serving cell using the TCI state pair.

[0129] In some embodiments of method 1000, the second DCI further includes a TA offset value, and wherein the UE uses the TA offset value to perform handover to the first candidate serving cell.

[0130] In some implementations of method 1000, the MAC-CE also includes a cell ID for the first candidate serving cell.

[0131] In some implementations of method 1000, the MAC-CE further includes a UL BWPID and a DL BWP ID for the first candidate serving cell.

[0132] In some embodiments of the method 1000, the MAC-CE further includes bits indicating that the TCI code point is used to identify two TCI state IDs of the first plurality of TCI state IDs.

[0133] In some embodiments of method 1000, the MAC-CE further includes a first value in the first 1-bit field indicating that the first TCI state of the TCI state pair is the UL TCI state and a second value in the second 1-bit field indicating that the second TCI state of the TCI state pair is the DLTCI state.

[0134] In some embodiments of method 1000, the MAC-CE also includes a TA usage field having a TA usage value, which indicates that the TA field in the MAC-CE is retained and the UE will communicate with the first candidate serving cell without using the TA offset value, and wherein the UE performs UL transmission during handover to the first candidate serving cell without using the TA offset value.

[0135] In some embodiments of method 1000, the MAC-CE also includes a TA usage field having a TA usage value, the TA usage value indicating that the TA field in the MAC-CE is retained and the UE will communicate with the first candidate serving cell based on the currently configured TA offset value for the first candidate serving cell, and wherein the UE uses the currently configured TA offset value for the first candidate serving cell to perform UL transmission during handover to the first candidate serving cell.

[0136] In some embodiments of method 1000, the MAC-CE further comprises: a TA usage field having a TA usage value, the TA usage value indicating that the UE will use a specified TA offset value to communicate with the first candidate serving cell, and the specified TA offset value is in the TA field, wherein the UE uses the specified TA offset value to perform UL transmission during handover to the first candidate serving cell.

[0137] In some embodiments of method 1000, the MAC-CE further comprises: a TA usage field having a TA usage value, the TA usage value indicating that the UE is to perform a CFRA procedure with the first candidate serving cell to determine a TA offset value to be used for communicating with the first candidate serving cell; and a TA field comprising: an SSB index in a first set of bits of the TA field, an SSB index of a plurality of PRACH resources and a spatial relationship that can be used by the UE as part of the CFRA procedure for selecting a PRACH transmission, and a PRACH index in a second set of bits of the TA field, the PRACH index being used by the UE as part of the CFRA procedure for selecting a PRACH resource from a plurality of PRACH resources, wherein the UE performs handover to the first candidate serving cell using the TA offset value determined by performing the CFRA procedure.

[0138] In some embodiments of method 1000, the MAC-CE further includes a timer value identifying a timer for determining whether handover to the first candidate serving cell has failed.

[0139] In some embodiments of method 1000, the MAC-CE also includes a UL grant identifying resources usable by the UE for UL transmission on the first candidate serving cell.

[0140] Figure 11 A method 1100 of a RAN according to embodiments herein is illustrated. The method 1100 includes receiving 1102 an L1 measurement report from a UE.

[0141] The method 1100 also includes identifying 1104 a first candidate serving cell and a second candidate serving cell for handover to be performed by the UE based on the L1 measurement report.

[0142] The method 1100 also includes transmitting 1106 to the UE a first DCI including scheduling information for the PDSCH.

[0143] Method 1100 also includes transmitting 1108 a MAC-CE of a PDSCH to the UE, the MAC-CE including a first plurality of TCI state IDs for a first activated TCI state of a first candidate serving cell and a second plurality of TCI state IDs for a second activated TCI state of a second candidate serving cell, wherein the first plurality of TCI state IDs are configured for use with a TCI code point to identify a first TCI state pair from the first activated TCI state, and wherein the second plurality of TCI state IDs are configured for use with a TCI code point to identify a second TCI state pair from the second activated TCI state.

[0144] The method 1100 also includes determining 1110 that the UE will perform a handover with the first candidate serving cell.

[0145] The method 1100 also includes transmitting 1112 to the UE a second DCI including the TCI code point and the physical cell ID of the first candidate serving cell.

[0146] The method 1100 also includes communicating 1114 with the UE on the first candidate serving cell to implement the handover to the first candidate serving cell.

[0147] In some implementations of method 1100, the second DCI further includes a TA offset value.

[0148] In some implementations of method 1100, the MAC-CE also includes a cell ID for the first candidate serving cell.

[0149] In some implementations of method 1100, the MAC-CE also includes a UL BWPID and a DL BWP ID for the first candidate serving cell.

[0150] In some embodiments of the method 1100, the MAC-CE further includes bits indicating that the TCI code point is used to identify two TCI state IDs of the first plurality of TCI state IDs.

[0151] In some embodiments of method 1100, the MAC-CE further includes a first value in the first 1-bit field indicating that the first TCI state of the TCI state pair is the UL TCI state and a second value in the second 1-bit field indicating that the second TCI state of the TCI state pair is the DLTCI state.

[0152] In some embodiments of method 1100, the MAC-CE further includes a TA usage field having a TA usage value indicating that the TA field in the MAC-CE is reserved and the UE will communicate with the first candidate serving cell without using a TA offset value.

[0153] In some embodiments of method 1100, the MAC-CE also includes a TA usage field having a TA usage value, which indicates that the TA field in the MAC-CE is reserved and the UE will communicate with the first candidate serving cell based on the currently configured TA offset value for the first candidate serving cell.

[0154] In some embodiments of method 1100, the MAC-CE further includes a TA usage field having a TA usage value indicating that the UE will use a specified TA offset value to communicate with the first candidate serving cell, and the specified TA offset value is in the TA field.

[0155] In some embodiments of method 1100, the MAC-CE also includes: a TA usage field having a TA usage value, the TA usage value indicating that the UE is to perform a CFRA process with the first candidate serving cell to determine a TA offset value to be used for communicating with the first candidate serving cell; and a TA field, the TA field including: an SSB index in a first set of bits of the TA field, an SSB index that can be used by the UE as part of the CFRA process to select multiple PRACH resources and spatial relationships for PRACH transmission, and a PRACH index in a second set of bits of the TA field, the PRACH index can be used by the UE as part of the CFRA process to select a PRACH resource from multiple PRACH resources.

[0156] In some embodiments of the method 1100, the MAC-CE further includes a timer value identifying a timer for determining whether handover to the first candidate serving cell has failed.

[0157] In some embodiments of method 1100, the MAC-CE also includes a UL grant identifying resources usable by the UE for UL transmission on the first candidate serving cell.

[0158] Figure 12 A method 1200 of a UE according to an embodiment of the present invention is illustrated. The method 1200 includes receiving 1202 a DCI including a TCI field having a TCI code point and scheduling information for a PDSCH from a network.

[0159] The method 1200 also includes receiving 1204 a MAC-CE on a PDSCH from the network, the MAC-CE including an indication to perform handover for the UE and a TCI state ID pair corresponding to a TCI state pair of a target non-serving cell for the handover.

[0160] The method 1200 also includes performing 1206 a handover to a target non-serving cell, the handover including communicating with the target non-serving cell using the TCI state pair.

[0161] Figure 13 A method 1300 of a RAN according to embodiments herein is illustrated. The method 1300 includes receiving 1302 an L1 measurement report from a UE.

[0162] The method 1300 also includes identifying 1304 a target non-serving cell for handover to be performed by the UE based on the L1 measurement report.

[0163] The method 1300 also includes transmitting 1306 to the UE a DCI including a TCI field having a TCI codepoint and scheduling information for the PDSCH.

[0164] The method 1300 also includes transmitting 1308 a MAC-CE of a PDSCH to the UE, the MAC-CE including an indication for the UE to perform handover to a target non-serving cell and a TCI state ID pair corresponding to the TCI state pair of the target non-serving cell for the handover.

[0165] The method 1300 also includes communicating 1310 with the UE on the target non-serving cell to implement the handover to the target non-serving cell.

[0166] Figure 14 A method 1400 of a UE according to an embodiment of the present invention is illustrated. The method 1400 includes receiving 1402 configuration information from a network defining a first CCG including a SpCell and one or more SCells, the configuration information dividing the SpCell and the one or more SCells into a first sub-CCG and a second sub-CCG.

[0167] The method 1400 also includes receiving 1404 a first MAC-CE for a first candidate cell from the network, the first MAC-CE indicating a first one or more TCI state IDs, wherein the first candidate cell is in a first sub-CCG.

[0168] The method 1400 also includes identifying 1406 first one or more activated TCI states at the first candidate cell by applying the first one or more TCI state IDs to a first TCI state list for the first candidate cell.

[0169] The method 1400 also includes identifying 1408 second one or more activated TCI states at a second candidate cell by applying the first one or more TCI state IDs to a second TCI state list for the second candidate cell, wherein the second candidate cell is in the first sub-CCG.

[0170] Method 1400 also includes communicating with the network on a first candidate cell based on one or more activated TCI states among the first one or more activated TCI states corresponding to the handover of the UE to the SpCell of the CCG, and communicating 1410 with the network on a second candidate cell based on one or more activated TCI states among the second one or more activated TCI states.

[0171] In some embodiments, method 1400 further includes: receiving a second MAC-CE for a third candidate cell from the network, the second MAC-CE indicating a second one or more TCI state IDs, wherein the third candidate cell is in the second sub-CCG; identifying a third one or more activated TCI states at the third candidate cell by applying the second one or more TCI state IDs to a third TCI state list for the third candidate cell; and communicating with the network on the third candidate cell based on one or more of the third one or more activated TCI states, corresponding to the handover of the UE to the SpCell of the CCG. Some such embodiments further include: identifying a fourth one or more activated TCI states at a fourth candidate cell by applying the second one or more TCI state IDs to a fourth TCI state list for a fourth candidate cell, wherein the fourth candidate cell is in the second sub-CCG; and communicating with the network on the fourth candidate cell based on one or more of the fourth one or more activated TCI states, corresponding to the handover of the UE to the SpCell of the CCG.

[0172] In some embodiments of method 1400, the first sub-CCG includes a SpCell.

[0173] In some embodiments of method 1400, the second sub-CCG comprises a SpCell.

[0174] In some embodiments, method 1400 further includes receiving a first TCI state list for the first candidate cell from the network in an RRC message.

[0175] In some implementations of method 1400, configuration information defining the CCG is received in an RRC message.

[0176] Figure 15 A method 1500 of a RAN according to an embodiment of the present invention is illustrated. The method 1500 includes transmitting 1502 to a UE configuration information defining a first CCG including a SpCell and one or more SCells, the configuration information dividing the SpCell and the one or more SCells into a first sub-CCG and a second sub-CCG.

[0177] The method 1500 also includes transmitting 1504 to the UE a first MAC-CE for a first candidate cell, the first MAC-CE indicating a first one or more TCI state IDs for use with a first TCI state list for the first candidate cell and a second TCI state list for a second candidate cell; wherein the first candidate cell and the second candidate cell are in a first sub-CCG.

[0178] The method 1500 also includes communicating 1506 with the UE on the first candidate cell and on the second candidate cell corresponding to the handover of the UE to the SpCell of the CCG.

[0179] In some embodiments, method 1500 further includes: transmitting a second MAC-CE for a third candidate cell to the UE, the second MAC-CE indicating a second one or more TCI state IDs for use with a third TCI state list for the third candidate cell, wherein the third candidate cell is in the second sub-CCG; and communicating with the UE on the third candidate cell corresponding to a handover of the UE to the SpCell of the CCG. In some such embodiments, the second one or more TCI state IDs are further used for use with a fourth TCI state list for a fourth candidate cell, wherein the fourth candidate cell is in the second sub-CCG, and the method further includes communicating with the UE on the fourth candidate cell corresponding to the handover of the UE to the SpCell of the CCG.

[0180] In some embodiments of method 1500, the first sub-CCG includes a SpCell.

[0181] In some embodiments of method 1500, the second sub-CCG comprises a SpCell.

[0182] In some embodiments, method 1500 further includes transmitting a first TCI state list for the first candidate cell to the UE in an RRC message.

[0183] In some implementations of method 1500, configuration information defining the CCG is transmitted in an RRC message.

[0184] Figure 16 A method 1600 of a UE according to an embodiment of the present invention is illustrated. The method 1600 includes receiving 1602 configuration information from a network defining a first CCG including a SpCell and one or more SCells, the configuration information dividing the SpCell and the one or more SCells into a first sub-CCG and a second sub-CCG.

[0185] The method 1600 also includes receiving 1604 a first MAC-CE for a first candidate cell from the network, the first MAC-CE indicating a first one or more TCI state IDs, wherein the first candidate cell is in a first sub-CCG.

[0186] The method 1600 also includes identifying 1606 first one or more activated TCI states at the first candidate cell and the second candidate cell by applying the first one or more TCI state IDs to a first TCI state list for the first sub-CCG, wherein the second candidate cell is in the first sub-CCG.

[0187] The method 1600 also includes communicating 1608 with the network on the first candidate cell and on the second candidate cell based on one or more of the first one or more activated TCI states corresponding to the handover of the UE to the SpCell of the CCG.

[0188] In some embodiments, method 1600 also includes: receiving a second MAC-CE for a third candidate cell from the network, the second MAC-CE indicating a second one or more TCI state IDs, wherein the third candidate cell is in the second sub-CCG; identifying second one or more activated TCI states at the third candidate cell and the fourth candidate cell by applying the second one or more TCI state IDs to a second TCI state list for the second sub-CCG, wherein the fourth candidate cell is in the second sub-CCG; and communicating with the network on the third candidate cell and on the fourth candidate cell based on one or more activated TCI states of the second one or more activated TCI states corresponding to the handover of the UE to the SpCell of the CCG.

[0189] In some embodiments of method 1600, the first sub-CCG includes a SpCell.

[0190] In some embodiments of method 1600, the second sub-CCG includes a SpCell.

[0191] In some embodiments, method 1600 further includes receiving a first TCI state list for the first sub-CCG from the network in an RRC message.

[0192] In some implementations of method 1600, configuration information defining the CCG is received in an RRC message.

[0193] Figure 17 A method 1700 of a RAN according to an embodiment of the present invention is illustrated. The method 1700 includes transmitting 1702 to a UE configuration information defining a first CCG including a SpCell and one or more SCells, the configuration information dividing the SpCell and the one or more SCells into a first sub-CCG and a second sub-CCG.

[0194] The method 1700 also includes transmitting 1704 a first MAC-CE for a first candidate cell to the UE, the first MAC-CE indicating first one or more TCI state IDs for use with a TCI state list for a first sub-CCG, wherein the first candidate cell is in the first sub-CCG.

[0195] The method 1700 also includes communicating 1706 with the UE on a first candidate cell and on a second candidate cell corresponding to a handover of the UE to the SpCell of the CCG, wherein the second candidate cell is in the first sub-CCG.

[0196] In some embodiments, method 1700 also includes: receiving a second MAC-CE for a third candidate cell from the network, the second MAC-CE indicating a second one or more TCI state IDs for use with the TCI state list for the second sub-CCG, wherein the third candidate cell is in the second sub-CCG; and communicating with the network on the third candidate cell and on a fourth candidate cell corresponding to the handover of the UE to the SpCell of the CCG, wherein the fourth candidate cell is in the second sub-CCG.

[0197] In some embodiments of method 1700, the first sub-CCG includes a SpCell.

[0198] In some embodiments of method 1700, the second sub-CCG includes a SpCell.

[0199] In some embodiments, method 1700 also includes transmitting the first TCI state list for the first sub-CCG to the UE in an RRC message.

[0200] In some implementations of method 1700, configuration information defining the CCG is transmitted in an RRC message.

[0201] Figure 18 A method 1800 of a UE according to an embodiment of the present invention is illustrated. The method 1800 includes receiving 1802 from a network a first configuration message including TAG-IDs for a plurality of candidate cells and a first PCI index value for a first candidate cell among the plurality of candidate cells.

[0202] The method 1800 also includes receiving 1804 a first MAC-CE from the network, the first MAC-CE including TAG-IDs for a plurality of candidate cells, a first PCI index value for a first candidate cell, and a data payload.

[0203] The method 1800 further includes receiving 1806 from the network a second MAC-CE corresponding to communication between the UE and the network on the first candidate cell, wherein the second MAC-CE includes TAG-IDs of the plurality of candidate cells and a PCI of the first candidate cell.

[0204] The method 1800 also includes using 1808 the data payload of the first MAC-CE to determine a configuration for communication between the UE and the network on the first candidate cell based on a correspondence between the PCI from the second MAC-CE and the PCI index value from the first MAC-CE for the first candidate cell.

[0205] The method 1800 further includes performing 1810 communication between the UE and the network on the first candidate cell according to the configuration.

[0206] In some embodiments of method 1800: the data payload includes a TAC for a first candidate cell, the communication between the UE and the first candidate cell includes a handover of the UE to the first candidate cell, and the value indicated by the TAC is used for UL transmissions between the UE and the first candidate cell corresponding to the handover of the UE to the first candidate cell. Some such embodiments also include storing, at the UE, an association between the TAC for the first candidate cell, a PCI index value for the first candidate cell, and the PCI of the first candidate cell. Some such embodiments also include receiving, from the network, an indication of a correspondence between the PCI for the first candidate cell and the PCI index value. In some such embodiments, the TAC includes a TA offset value. In some such embodiments, the TAC includes a TA offset adjustment value. In some such embodiments, the first MAC-CE is a RAR MAC-CE. In some such embodiments, the first MAC-CE is a TAC MAC-CE.

[0207] In some implementations of method 1800, the first configuration message further includes a second PCI index value for a second candidate cell among the plurality of candidate cells.

[0208] In some embodiments, method 1800 further includes receiving, from the network, a second configuration message including a second PCI index value for a second candidate cell among the plurality of candidate cells.

[0209] In some embodiments, the method 1800 further includes receiving a second configuration message from the network including a replacement PCI index value for a first candidate cell among the plurality of candidate cells.

[0210] Figure 19 A method 1900 of a RAN according to embodiments herein is illustrated. The method 1900 includes transmitting 1902 to a UE a first configuration message including TAG-IDs for a plurality of candidate cells and a first PCI index value for a first candidate cell among the plurality of candidate cells.

[0211] The method 1900 also includes transmitting 1904 a first MAC-CE to the UE, the first MAC-CE including: TAG-IDs for multiple candidate cells, a first PCI index value for a first candidate cell, and a data payload for configuring communication between the UE and the RAN on the first candidate cell.

[0212] The method 1900 further includes transmitting 1906 to the UE a second MAC-CE corresponding to communication between the UE and the RAN on the first candidate cell, wherein the second MAC-CE includes TAG-IDs of the plurality of candidate cells and a PCI of the first candidate cell.

[0213] The method 1900 also includes performing 1908 communication between the UE and the RAN on the first candidate cell.

[0214] In some embodiments of method 1900: the data payload includes a TAC for a first candidate cell, and the communication between the UE and the first candidate cell includes a handover of the UE to the first candidate cell. In some such embodiments, the TAC includes a TA offset value. In some such embodiments, the TAC includes a TA offset adjustment value. In some such embodiments, the first MAC-CE is a RAR MAC-CE. In some such embodiments, the first MAC-CE is a TAC MAC-CE.

[0215] In some implementations of method 1900, the first configuration message further includes a second PCI index value for a second candidate cell among the plurality of candidate cells.

[0216] In some embodiments, method 1900 also includes transmitting, to the UE, a second configuration message including a second PCI index value for a second candidate cell among the plurality of candidate cells.

[0217] In some embodiments, method 1900 also includes transmitting a second configuration message to the UE including a replacement PCI index value for a first candidate cell among the plurality of candidate cells.

[0218] Figure 20 An example architecture of a wireless communication system 2000 according to the embodiments disclosed herein is illustrated. The following description is provided for an example wireless communication system 2000 operating in conjunction with the LTE system standard and / or the 5G or NR system standard provided in the 3GPP technical specifications.

[0219] like Figure 20 As shown, wireless communication system 2000 includes UE 2002 and UE 2004 (although any number of UEs may be used). In this example, UE 2002 and UE 2004 are illustrated as smartphones (e.g., handheld touchscreen mobile computing devices capable of connecting to one or more cellular networks), but may also include any mobile or non-mobile computing device configured for wireless communication.

[0220] UE 2002 and UE 2004 may be configured to be communicatively coupled to RAN 2006. In an embodiment, RAN 2006 may be NG-RAN, E-UTRAN, etc. UE 2002 and UE 2004 utilize connections (or channels) (shown as connection 2008 and connection 2010, respectively) with RAN 2006, where each connection (or channel) includes a physical communication interface. RAN 2006 may include one or more base stations (such as base station 2012 and base station 2014) that implement connection 2008 and connection 2010.

[0221] In this example, connection 2008 and connection 2010 are the air interfaces used to achieve this communicative coupling and may conform to the RAT used by RAN 2006, such as LTE and / or NR.

[0222] In some embodiments, UE 2002 and UE 2004 may also directly exchange communication data via side link interface 2016. UE 2004 is shown as being configured to access an access point (shown as AP 2018) via connection 2020. By way of example, connection 2020 may include a local wireless connection, such as a connection conforming to any IEEE 802.11 protocol, wherein AP 2018 may include a local wireless connection. In this example, AP 2018 may not be connected to another network (eg, the Internet) through CN 2024.

[0223] In an embodiment, UE 2002 and UE 2004 may be configured to communicate with each other or with base station 2012 and / or base station 2014 over a multi-carrier communication channel using orthogonal frequency division multiplexing (OFDM) communication signals according to various communication techniques, such as, but not limited to, orthogonal frequency division multiple access (OFDMA) communication techniques (e.g., for downlink communication) or single-carrier frequency division multiple access (SC-FDMA) communication techniques (e.g., for uplink and ProSe or sidelink communication), although the scope of the embodiment is not limited in this respect. An OFDM signal may include multiple orthogonal subcarriers.

[0224] In some embodiments, all or part of base station 2012 or base station 2014 may be implemented as one or more software entities running on a server computer as part of a virtual network. Additionally, or in other embodiments, base station 2012 or base station 2014 may be configured to communicate with each other via interface 2022. In embodiments where wireless communication system 2000 is an LTE system (e.g., when CN 2024 is an EPC), interface 2022 may be an X2 interface. This X2 interface may be defined between two or more base stations (e.g., two or more eNBs, etc.) connected to an EPC and / or between two eNBs connected to an EPC. In embodiments where wireless communication system 2000 is an NR system (e.g., when CN 2024 is a 5GC), interface 2022 may be an Xn interface. This Xn interface is defined between two or more base stations (e.g., two or more gNBs, etc.) connected to a 5GC, between base station 2012 (e.g., a gNB) and an eNB connected to a 5GC, and / or between two eNBs connected to a 5GC (e.g., CN 2024).

[0225] RAN 2006 is shown as being communicatively coupled to CN 2024. CN 2024 may include one or more network elements 2026 configured to provide various data and telecommunication services to customers / subscribers (e.g., UE 2002 and users of UE 2004) connected to CN 2024 via RAN 2006. Components of CN 2024 may be implemented in one physical device or separate physical devices that include components for reading and executing instructions from a machine-readable or computer-readable medium (e.g., a non-transitory machine-readable storage medium).

[0226] In an embodiment, CN 2024 may be an EPC, and RAN 2006 may be connected to CN 2024 via an S1 interface 2028. In an embodiment, S1 interface 2028 may be divided into two parts: an S1 user plane (S1-U) interface, which carries traffic data between base station 2012 or base station 2014 and a serving gateway (S-GW); and an S1-MME interface, which is a signaling interface between base station 2012 or base station 2014 and a mobility management entity (MME).

[0227] In an embodiment, CN 2024 may be a 5GC, and RAN 2006 may be connected to CN 2024 via an NG interface 2028. In an embodiment, NG interface 2028 may be divided into two parts: an NG user plane (NG-U) interface, which carries service data between base station 2012 or base station 2014 and a user plane function (UPF); and an S1 control plane (NG-C) interface, which is a signaling interface between base station 2012 or base station 2014 and an access and mobility management function (AMF).

[0228] Generally speaking, the application server 2030 may be a component that provides applications (e.g., packet-switched data services) that utilize Internet Protocol (IP) bearer resources with the CN 2024. The application server 2030 may also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for the UE 2002 and UE 2004 via the CN 2024. The application server 2030 may communicate with the CN 2024 via an IP communication interface 2032.

[0229] Figure 21 A system 2100 is illustrated for performing signaling 2134 between a wireless device 2102 and a network device 2118 according to embodiments disclosed herein. The system 2100 can be part of a wireless communication system as described herein. The wireless device 2102 can be, for example, a UE of the wireless communication system. The network device 2118 can be, for example, a base station (e.g., an eNB or gNB) of the wireless communication system.

[0230] The wireless device 2102 may include one or more processors 2104. The processor 2104 may execute instructions to perform various operations for the wireless device 2102, as described herein. The processor 2104 may include one or more baseband processors implemented using, for example, a central processing unit (CPU), a digital signal processor (DSP), an application specific integrated circuit (ASIC), a controller, a field programmable gate array (FPGA) device, another hardware device, a firmware device, or any combination thereof, configured to perform the operations described herein.

[0231] The wireless device 2102 may include a memory 2106. The memory 2106 may be a non-transitory computer-readable storage medium that stores instructions 2108, which may include, for example, instructions to be executed by the processor 2104. The instructions 2108 may also be referred to as program code or a computer program. The memory 2106 may also store data used by the processor 2104 and results computed by the processor.

[0232] The wireless device 2102 may include one or more transceivers 2110, which may include radio frequency (RF) transmitter and / or receiver circuitry that uses an antenna 2112 of the wireless device 2102 to facilitate signaling (e.g., signaling 2134) to and / or from the wireless device 2102 and other devices (e.g., network device 2118) in accordance with a corresponding RAT.

[0233] The wireless device 2102 may include one or more antennas 2112 (e.g., one, two, four, or more). For embodiments with multiple antennas 2112, the wireless device 2102 may take advantage of the spatial diversity of such multiple antennas 2112 to transmit and / or receive multiple different data streams on the same time-frequency resources. This behavior may be referred to as, for example, multiple-input multiple-output (MIMO) behavior (referring to the multiple antennas used at each of the transmitting device and the receiving device to implement this aspect). The MIMO transmission performed by the wireless device 2102 may be implemented based on precoding (or digital beamforming) applied at the wireless device 2102, which multiplexes the data streams between the antennas 2112 based on known or assumed channel characteristics, so that each data stream is received with appropriate signal strength relative to the other streams and at a desired location in the spatial domain (e.g., the location of the receiver associated with the data stream). Certain embodiments may use single-user MIMO (SU-MIMO) methods (where data streams are all directed to a single receiver) and / or multi-user MIMO (MU-MIMO) methods (where separate data streams may be directed to separate (different) receivers in different locations in the spatial domain).

[0234] In certain embodiments with multiple antennas, the wireless device 2102 may implement analog beamforming techniques whereby the phases of the signals transmitted by the antennas 2112 are relatively adjusted so that the (joint) transmissions of the antennas 2112 can be directed (this is sometimes referred to as beam steering).

[0235] The wireless device 2102 may include one or more interfaces 2114. The interfaces 2114 may be used to provide input to or output from the wireless device 2102. For example, the wireless device 2102 (UE) may include interfaces 2114, such as a microphone, a speaker, a touch screen, and buttons, to allow a user of the UE to provide input to and / or output to the UE. Other interfaces of such a UE may consist of transmitters, receivers, and other circuits that allow communication between the UE and other devices (e.g., in addition to the transceiver 2110 / antenna 2112 already described) and may be configured in accordance with known protocols (e.g., etc.) to perform the operation.

[0236] The wireless device 2102 may include an L1 / L2 mobility module 2116. The L1 / L2 mobility module 2116 may be implemented via hardware, software, or a combination thereof. For example, the L1 / L2 mobility module 2116 may be implemented as a processor, circuitry, and / or instructions 2108 stored in the memory 2106 and executed by the processor 2104. In some examples, the L1 / L2 mobility module 2116 may be integrated within the processor 2104 and / or the transceiver 2110. For example, the L1 / L2 mobility module 2116 may be implemented by a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuits) within the processor 2104 or the transceiver 2110.

[0237] The L1 / L2 mobility module 2116 may be used in various aspects of the present disclosure, such as Figures 1 to 19 The L1 / L2 mobility module 2116 is configured to: receive a cell handover command as a combination of DC and MAC-CE and perform the corresponding handover; receive TCI state IDs and apply these TCI state IDs for all candidate cells of a sub-CCG in a configured CCG; and / or receive and use information (including TA information) from the network via a TAG-specific PCI index for a group of candidate cells in a TAG in the manner described herein.

[0238] The network device 2118 may include one or more processors 2120. The processors 2120 may execute instructions to perform various operations for the network device 2118, as described herein. The processors 2120 may include one or more baseband processors implemented using, for example, a CPU, a DSP, an ASIC, a controller, an FPGA device, another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein.

[0239] The network device 2118 may include a memory 2122. The memory 2122 may be a non-transitory computer-readable storage medium that stores instructions 2124 (which may include, for example, instructions to be executed by the processor 2120). The instructions 2124 may also be referred to as program code or a computer program. The memory 2122 may also store data used by the processor 2120 and results calculated by the processor.

[0240] The network device 2118 may include one or more transceivers 2126, which may include RF transmitter and / or receiver circuitry that uses an antenna 2128 of the network device 2118 to facilitate signaling (e.g., signaling 2134) to and / or from the network device 2118 and other devices (e.g., wireless device 2102) according to a corresponding RAT.

[0241] The network device 2118 may include one or more antennas 2128 (e.g., one, two, four, or more). In embodiments with multiple antennas 2128, the network device 2118 may perform MIMO, digital beamforming, analog beamforming, beam steering, etc., as described.

[0242] The network device 2118 may include one or more interfaces 2130. The interfaces 2130 may be used to provide input to or output from the network device 2118. For example, a network device 2118 that is a base station may include an interface 2130 consisting of a transmitter, a receiver, and other circuits (e.g., in addition to the transceiver 2126 / antenna 2128 already described) that enables the base station to communicate with other equipment in the core network and / or enables the base station to communicate with external networks, computers, databases, etc. for the purpose of operating, managing, and maintaining the base station or other equipment operably connected to the base station.

[0243] The network device 2118 may include an L1 / L2 mobility module 2132. The L1 / L2 mobility module 2132 may be implemented via hardware, software, or a combination thereof. For example, the L1 / L2 mobility module 2132 may be implemented as a processor, circuitry, and / or instructions 2124 stored in the memory 2122 and executed by the processor 2120. In some examples, the L1 / L2 mobility module 2132 may be integrated within the processor 2120 and / or the transceiver 2126. For example, the L1 / L2 mobility module 2132 may be implemented by a combination of software components (e.g., executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuits) within the processor 2120 or the transceiver 2126.

[0244] The L1 / L2 mobility module 2132 may be used in various aspects of the present disclosure, such as Figures 1 to 19 The L1 / L2 mobility module 2132 is configured to: cause the network device 2118 to send a cell handover command as a combination of DC and MAC-CE; configure a sub-CCG and send a TCI state ID for use by all candidate cells for the sub-CCG; and / or configure information (including TA information) using a TAG-specific PCI index for a group of candidate cells in a TAG in the manner described herein and convey the information to the UE.

[0245] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of any of methods 800, 1000, 1200, 1400, 1600, and 1800. The apparatus may be, for example, a UE, such as wireless device 2102 (UE), as described herein.

[0246] Embodiments contemplated herein include one or more non-transitory computer-readable media including instructions for causing the electronic device to perform one or more elements of any of methods 800, 1000, 1200, 1400, 1600, and 1800 when the instructions are executed by one or more processors of the electronic device. The non-transitory computer-readable medium may be, for example, a memory of a UE (such as memory 2106 of wireless device 2102 (UE), as described herein).

[0247] Embodiments contemplated herein include an apparatus comprising logical components, modules, or circuits for performing one or more elements of any of methods 800, 1000, 1200, 1400, 1600, and 1800. The apparatus may be, for example, a UE, such as wireless device 2102 (UE), as described herein.

[0248] Embodiments contemplated herein include an apparatus comprising: one or more processors; and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of any of methods 800, 1000, 1200, 1400, 1600, and 1800. The apparatus may be, for example, a UE, such as wireless device 2102 (UE), as described herein.

[0249] Embodiments contemplated herein include a signal as described in or associated with one or more elements of any of method 800 , method 1000 , method 1200 , method 1400 , method 1600 , and method 1800 .

[0250] The embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processor causes the processor to perform one or more elements of any of methods 800, 1000, 1200, 1400, 1600, and 1800. The processor may be a processor of a UE (such as processor 2104 of wireless device 2102 (UE), as described herein). These instructions may be located, for example, in the processor and / or in a memory of the UE (such as memory 2106 of wireless device 2102 (UE), as described herein).

[0251] Embodiments contemplated herein include an apparatus comprising means for performing one or more elements of any of methods 900, 1100, 1300, 1500, 1700, and 1900. The apparatus may be, for example, a base station, such as network device 2118 (base station), as described herein.

[0252] Embodiments contemplated herein include one or more non-transitory computer-readable media including instructions for causing the electronic device to perform one or more elements of any of methods 900, 1100, 1300, 1500, 1700, and 1900 when executed by one or more processors of the electronic device. The non-transitory computer-readable medium may be, for example, a memory of a base station (such as memory 2122 of network device 2118 (base station), as described herein).

[0253] Embodiments contemplated herein include an apparatus comprising logic, modules, or circuitry for performing one or more elements of any of methods 900, 1100, 1300, 1500, 1700, and 1900. The apparatus may be, for example, a base station, such as network device 2118 (base station), as described herein.

[0254] Embodiments contemplated herein include an apparatus comprising: one or more processors; and one or more computer-readable media comprising instructions that, when executed by the one or more processors, cause the one or more processors to perform one or more elements of any of methods 900, 1100, 1300, 1500, 1700, and 1900. The apparatus may be, for example, a base station, such as network device 2118 (base station), as described herein.

[0255] Embodiments contemplated herein include a signal as described in or associated with one or more elements of any of method 900 , method 1100 , method 1300 , method 1500 , method 1700 , and method 1900 .

[0256] The embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processing element causes the processing element to perform one or more elements of any of methods 900, 1100, 1300, 1500, 1700, and 1900. The processor may be a processor of a base station (such as processor 2120 of network device 2118 (base station), as described herein). These instructions may be located, for example, in the processor and / or on a memory of the base station (such as memory 2122 of network device 2118 (base station), as described herein).

[0257] For one or more embodiments, at least one component of the components described in one or more of the preceding figures may be configured to perform one or more operations, techniques, processes, and / or methods as described herein. For example, a baseband processor as described herein in conjunction with one or more of the preceding figures may be configured to operate according to one or more of the examples described herein. For another example, circuitry associated with a UE, base station, network element, etc. as described above in conjunction with one or more of the preceding figures may be configured to operate according to one or more of the examples described herein.

[0258] Unless otherwise expressly stated, any of the above embodiments may be combined with any other embodiment (or combination of embodiments). The foregoing description of one or more specific implementations provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise forms disclosed. In view of the above teachings, modifications and variations are possible or can be obtained from the practice of the various embodiments.

[0259] Embodiments and implementations of the systems and methods described herein may include various operations that may be embodied in machine-executable instructions to be executed by a computer system. A computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). A computer system may include hardware components that include specific logic for performing the operations; or may include a combination of hardware, software, and / or firmware.

[0260] It should be appreciated that the systems described herein include descriptions of specific embodiments. These embodiments can be combined into a single system, partially combined into other systems, separated into multiple systems, or otherwise divided or combined. In addition, it is contemplated that parameters, attributes, aspects, etc. of one embodiment may be used in conjunction with another embodiment. For clarity, these parameters, attributes, aspects, etc. are described only in relation to one or more embodiments, and it should be appreciated that these parameters, attributes, aspects, etc. may be combined with or substituted for parameters, attributes, aspects, etc. of another embodiment unless expressly stated otherwise herein.

[0261] It is understood that the use of personally identifiable information should be subject to privacy policies and practices that are generally recognized to meet or exceed industry or government requirements for maintaining user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users.

[0262] Although the foregoing has been described in considerable detail for purposes of clarity, it will be apparent that certain changes and modifications may be made without departing from the principles of the invention. It should be noted that there are many alternative ways of implementing both the processes and the apparatus described herein. The embodiments of the present invention are therefore to be considered illustrative and not restrictive, and the description is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.

Claims

1. A method of a user equipment (UE), comprising: receiving, from a network, a first configuration message including a timing advance group (TAG) identifier (ID) (TAG-ID) for a plurality of candidate cells and a first physical cell identity (PCI) index value for a first candidate cell among the plurality of candidate cells; A first MAC-CE is received from the network, where the first MAC-CE includes: the TAG-IDs for the multiple candidate cells; the first PCI index value for the first candidate cell; and Data payload; receiving, from the network, a second MAC-CE corresponding to communication between the UE and the network on the first candidate cell, wherein the second MAC-CE includes the TAG-IDs of the plurality of candidate cells and the PCI of the first candidate cell; and using the data payload of the first MAC-CE to determine a configuration for the communication between the UE and the network on the first candidate cell based on a correspondence between the PCI from the second MAC-CE and the PCI index value from the first MAC-CE for the first candidate cell; and The communication between the UE and the network is performed on the first candidate cell according to the configuration.

2. The method according to claim 1, wherein: The data payload includes a timing advance (TA) command (TAC) for the first candidate cell; The communication between the UE and the first candidate cell includes a handover of the UE to the first candidate cell; and The value indicated by the TAC is used for uplink (UL) transmission between the UE and the first candidate cell corresponding to the handover of the UE to the first candidate cell.

3. The method of claim 2, further comprising storing, at the UE, an association between the TAC for the first candidate cell, the PCI index value for the first candidate cell, and the PCI of the first candidate cell.

4. The method of claim 2, further comprising receiving an indication of the correspondence between the PCI and the PCI index value for the first candidate cell from the network. The method of claim 2 , wherein the TAC comprises a TA offset value. The method of claim 2 , wherein the TAC comprises a TA offset adjustment value.

7. The method of claim 2, wherein the first MAC-CE is a Random Access Response (RAR) MAC-CE. The method of claim 2 , wherein the first MAC-CE is a TAC MAC-CE. 9 . The method according to claim 1 , wherein the first configuration message further includes a second PCI index value for a second candidate cell among the plurality of candidate cells.

10. The method of claim 1, further comprising receiving, from the network, a second configuration message including a second PCI index value for a second candidate cell among the plurality of candidate cells.

11. The method of claim 1 , further comprising receiving a second configuration message from the network comprising a replacement PCI index value for the first candidate cell among the plurality of candidate cells.

12. A method of a radio access network (RAN), comprising: transmitting, to a user equipment (UE), a first configuration message including a timing advance group (TAG) identifier (ID) (TAG-ID) for a plurality of candidate cells and a first physical cell identity (PCI) index value for a first candidate cell among the plurality of candidate cells; Transmitting a first MAC-CE to the UE, where the first MAC-CE includes: the TAG-IDs for the multiple candidate cells; the first PCI index value for the first candidate cell; and a data payload for configuring communication between the UE and the RAN on the first candidate cell; transmitting, to the UE, a second MAC-CE corresponding to the communication between the UE and the RAN on the first candidate cell, wherein the second MAC-CE includes the TAG-IDs of the plurality of candidate cells and the PCI of the first candidate cell; and The communication between the UE and the RAN is performed on the first candidate cell.

13. The method according to claim 12, wherein: The data payload includes a timing advance (TA) command (TAC) for the first candidate cell; and The communication between the UE and the first candidate cell includes a handover of the UE to the first candidate cell. The method of claim 13 , wherein the TAC comprises a TA offset value. The method of claim 13 , wherein the TAC comprises a TA offset adjustment value.

16. The method of claim 13, wherein the first MAC-CE is a Random Access Response (RAR) MAC-CE. The method according to claim 13 , wherein the first MAC-CE is a TACMAC-CE.

18. The method according to claim 12, wherein the first configuration message further includes a second PCI index value for a second candidate cell among the plurality of candidate cells.

19. The method of claim 12, further comprising transmitting, to the UE, a second configuration message including a second PCI index value for a second candidate cell among the plurality of candidate cells.

20. The method of claim 12, further comprising transmitting, to the UE, a second configuration message comprising a replacement PCI index value for the first candidate cell of the plurality of candidate cells.

21. An apparatus comprising means for performing the method according to any one of claims 1 to 20.

22. A computer-readable medium comprising instructions for causing an electronic device to perform the method according to any one of claims 1 to 20 when the instructions are executed by one or more processors of the electronic device.

23. An apparatus comprising logic components, modules or circuits operable to perform the method of any one of claims 1 to 20.

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