Random access channel enhancements for supporting two timing advances with respect to single serving cell configuration with user equipment triggered random access channel

Abstract

Random access channel (RACH) enhancements for supporting two timing advance (TA) with respect to a single serving cell configuration are discussed herein. There may be two TAs configured / operated with respect to the same (single) serving cell used by a user equipment (UE). At a UE, two timing advance groups (TAGs) may be understood according to the two TAGs. Some proposals herein relate to the use of RACH operations triggered by a network by using PDCCH commands transmitted to a UE. Some proposals herein relate to using RACH operations triggered at / by a UE. In various embodiments, inter-cell and / or intra-cell contexts corresponding to the two TA situations may be applicable.

Description

Technical Field

[0001] This application relates to wireless communication systems in general, including wireless communication systems that support two timing advances configured relative to the same serving cell. Background Technology

[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, for instance, 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) (often referred to as Wi-Fi within the industry organization). ® ).

[0003] As envisioned by 3GPP, different wireless communication system standards and protocols can use various radio access networks (RANs) for communication between RAN base stations (sometimes also commonly referred to as RAN nodes, network nodes, or simply nodes) and wireless communication equipment called user equipment (UEs). 3GPP RANs can include, for example, Global System for Mobile Communications (GSM), Enhanced Data Rate 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 communication between the base station and the UE. For example, GERAN implements the GSM and / or EDGE RAT, UTRAN implements the Universal Mobile Telecommunications System (UMTS) RAT or other 3GPP RATs, E-UTRAN implements the LTE RAT (sometimes simply referred to as LTE), and NG-RAN implements the NR RAT (this NR RAT is sometimes referred to herein as the 5G RAT, 5G NR RAT, or simply NR). In some deployments, E-UTRAN may also implement the NR RAT. In some deployments, NG-RAN may also implement the LTE RAT.

[0005] The base stations used by a RAN can correspond to that RAN. An example of an E-UTRAN base station is an Evolved Universal Terrestrial Radio Access Network (E-UTRAN) Node B (also commonly referred to as 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 called gNodeB or gNB).

[0006] The RAN provides communication services to external entities through its connection with the core network (CN). For example, E-UTRAN can utilize the evolved packet core (EPC), while NG-RAN can utilize the 5G core network (5GC).

[0007] 5G NR frequency bands can be divided into two or more distinct frequency ranges. For example, Frequency Range (FR) 1 (FR1) may include bands operating at frequencies below 6 GHz, some of which are available in previous standards and can potentially be extended to cover new spectrum offerings from 410 MHz to 7125 MHz. Frequency Range 2 (FR2) may include bands from 24.25 GHz to 52.6 GHz. It should be noted that in some systems, FR2 may also include bands from 52.6 GHz to 71 GHz (or higher). Bands in the millimeter-wave (mmWave) range of FR2 may have smaller coverage areas but potentially higher available bandwidth than bands in FR1. Those skilled in the art will recognize that these frequency ranges, presented by way of example, may change over time or in different regions. Attached Figure Description

[0008] To facilitate the identification of any particular element or action in the discussion, one or more of the most significant digits in the figure reference numerals refer to the figure number in which the element was first introduced.

[0009] Figure 1 A first schematic diagram illustrating the physical channel aspect of a transmission between a UE, a first TRP, and a second schematic diagram illustrating the corresponding UL timing aspect of such transmission is illustrated according to an embodiment of this document.

[0010] Figure 2 An example is shown that includes an IE (Index) to identify the sequence to be used to generate a preamble for CFRA.

[0011] Figure 3 A method for a UE according to the implementation scheme of this document is illustrated.

[0012] Figure 4 An example of a RAN method according to the implementation scheme described herein is given.

[0013] Figure 5 A method for a UE according to the implementation scheme of this document is illustrated.

[0014] Figure 6 An example of a RAN method according to the implementation scheme described herein is given.

[0015] Figure 7 An example architecture of a wireless communication system according to the implementation scheme disclosed herein is illustrated.

[0016] Figure 8 A system for performing signaling between a wireless device and a network device according to an embodiment disclosed herein is illustrated. Detailed Implementation

[0017] Various implementations are described with respect to the UE. However, references to the UE are provided for illustrative purposes only. The example implementations can be used with any electronic component capable of establishing a connection to a network and configured with hardware, software, and / or firmware for exchanging information and data with the network. Therefore, the UE as described herein is used to represent any suitable electronic component.

[0018] Improvements to the use of multiple transmit / receive points (TRPs) (mTRPs) at the network and / or multiple antenna panels at the UE can improve the overall usability of wireless communication systems.

[0019] It has been recognized that in various wireless communication systems operating according to 3GPP specifications, the Physical Downlink Shared Channel (PDSCH) / Physical Downlink Control Channel (PDCCH) / Physical Uplink Control Channel (PUCCH) / Physical Uplink Shared Channel (PUSCH) use the assumption that different TRPs are perceived as synchronized by the UE, because the Maximum Receive Timing Difference (MRTD) for channels using different TRPs relative to the UE is less than the Cyclic Prefix (CP) used at the UE. However, it has been determined that, in practice, from the UE's perspective, the MRTD between different TRPs may be greater than the CP used by the UE, ultimately leading to perceived interference relative to the TRP for communication with that TRP. One such situation may occur when the timing synchronization error between two TRPs is large and the distance difference between the antenna panel and its corresponding TRP is large.

[0020] Figure 1 An example is illustrated according to the embodiment described herein, showing the first TRP 106 (in UE 104). Figure 1 The middle one is marked as "TRP1") and the second TRP 108 (in Figure 1 A first schematic diagram 100 illustrates the physical channel aspect of the transmission between TRPs 106 and 108, and a second schematic diagram 102 illustrates the corresponding uplink (UL) timing aspect for that transmission. As illustrated, UE 104 can communicate with each of the first TRP 106 and the second TRP 108 in the UL and / or downlink (DL) directions.

[0021] Relative to UL, the UE can perform UL transmission 110 at transmission time 112. Then, due to the distance difference between the UE 104 and each of the first TRP 106 and the second TRP 108, a first UL reception 114 can occur at the first TRP 106 at a first UL reception time 116 corresponding to the first propagation delay 118, while a second UL reception 120 can occur at the second TRP 108 at a second UL reception 120 corresponding to the second propagation delay 124. Furthermore, the timing synchronization error / inconsistency (or vice versa) at the first TRP 106 relative to the second TRP 108 can increase the effective difference between the first UL reception time 116 and the second UL reception 120. Based on, for example, the combination of the propagation delay difference for each of the first TRP 106 and the second TRP 108 and the synchronization error between the first TRP 106 and the second TRP 108, the total effective MRTD between the first TRP 106 and the second TRP 108 may exceed the CP used by the UE.

[0022] Therefore, it has been determined that specifying multiple timing advances (TAs) is beneficial for UL multi-downlink control information (DCI) for mTRP operation. For example, in the mTRP case, it may be beneficial to implement two TAs for UL multi-DCI (and optionally, for example, along with power control for UL single-DCI for mTRP operation, assuming a unified transmit configuration indicator (TCI) framework extension).

[0023] Therefore, it has also been determined that supporting the configuration and use of two TAs relative to two timing advance groups (TAGs) configured relative to the same serving cell used at the UE is beneficial. For example, for multi-DCI based mTRP operations using two TAs, supporting the configuration of two TAGs relative to a (single) serving cell configured at the UE may be advantageous.

[0024] In an inter-cell context, this might mean that the UE knows two independent TAs that should be used for two different cells, one serving cell and the other non-serving cell. Therefore, the embodiments described herein envision using two TAGs in an inter-cell mTRP context, where each TAG uses an independent TA. In such a context, it is understood that the first cell of the network accessed by the UE via a first TRP is a member of the first TAG using the first TA (and therefore, transmissions made by the UE on the first cell use the first TA), and the second cell of the network accessed by the UE via a second TRP is a member of the second TAG using the second TA (and therefore, transmissions made by the UE on the second cell use the second TA). Furthermore, as noted herein, cases are envisioned where TAs are used for two different cells, one serving cell and the other non-serving cell. Therefore, the embodiments described herein may identify the two cells under consideration as either a serving cell among "serving cells" or a non-serving cell among one or more "non-serving cells." Finally, it should be understood that in these contexts, each of the two cells operates as a "neighboring cell" of the other cell.

[0025] Within an inter-cell context, the UE can determine which two independent TAs should be used in the same (single) cell, with the choice of which TA to use being context-dependent. Therefore, the embodiments described herein also envision using two TAGs within an intra-cell mTRP context, where each TAG uses an independent TA. In such a context, it is understood that the UE accesses the cell on the first TRP based on the first TAG using the first TA (and thus, transmissions made by the UE to the first TRP on the cell use the first TA), and the UE accesses the cell on the second TRP based on the second TAG using the second TA (and thus, transmissions made by the UE to the second TRP on the cell use the second TA).

[0026] The proposals described herein relate to specific solutions / improvements to Random Access Channel (RACH) enhancements (RACH operations between the UE and the network) in the context of two TAs configured / operated relative to the same (single) serving cell used by the UE. Some proposals in this paper involve using RACH operations triggered by the network through PDCCH commands transmitted to the UE. Other proposals involve using RACH operations triggered at the UE (e.g., instead of PDCCH commands provided by the network).

[0027] Implementation scheme of RACH operation triggered by PDCCH command

[0028] In some cases, the DCI transmitted from the network to the UE may include a PDCCH command that triggers the UE to initiate a RACH operation to the network. For example, it is possible that the UE is out of sync (OOS) and there is Mobile Station Call (MT) DL data for the UE at the network. In such cases, the network may first signal the PDCCH command to the UE before scheduling the DL data. The PDCCH command triggers the UE to perform a First Physical Random Access Channel (PRACH) transmission to perform the RACH operation. As a result of the RACH operation thus triggered, the network can update the UE using the current TA that the UE should use to communicate with the network.

[0029] In some wireless communication systems, the DCI containing the PDCCH command may be in format 1_0, with cyclic redundancy check (CRC) data scrambled by the applicable cell-radio network temporary identifier (C-RNTI), and including a frequency domain resource allocation (FDRA) field with one bit in each bit. Furthermore, in some wireless communication systems, the DCI containing the PDCCH command may include one or more of the following:

[0030] • The random access preamble index set according to the ra-PreambleIndex information element (IE) (the field used for this value can be, for example, six bits).

[0031] • UL / Supplementary Uplink (SUL) indicator, which indicates the UL carrier in the cell on which PRACH is transmitted when the random access preamble index is not all zero and when the UE has a supplementaryUplink data member configured in the ServingCellConfig IE for the applicable cell (the field for this value may be, for example, one bit).

[0032] • Synchronization Signal (SS) / Physical Broadcast Channel (PBCH) Index, which indicates the SS / PBCH used to determine the RACH timing (RO) for PRACH transmission when the bits of the Random Access Preamble Index are not all zero (the field for this value may be, for example, 6 bits).

[0033] • PRACH mask index, which indicates the RO associated with the SS / PBCH index used for PRACH transmission when the bits of the random access preamble index are not all zero (the field for this value can be, for example, 4 bits); and

[0034] • Reserved bits, of which, for example, 12 reserved bits may exist when operating in a cell with shared spectrum channel access in FR1 or when monitoring DCI format in the common search space to operate in a cell in FR2-2; otherwise, 10 such reserved bits may exist.

[0035] In some implementations, within an inter-cell mTRP context using two TAGs with independent TAs, a PDCCH command received at the UE on the first cell can be used to trigger a PRACH transmission from the UE to a neighboring cell. Such a PDCCH command may include a PRACH target cell information field that provides the UE with PRACH target cell information identifying the considered neighboring cell. It can be assumed (and the network can ensure) that the neighboring cell transmits / carries a synchronization signal block (SSB) identified by the SS / PBCH index of the DCI, such that an appropriate RO can be identified on the neighboring cell relative to this SSB for the PRACH transmission corresponding to the PDCCH command. Such a PDCCH command may be carried by, for example, a DCI of format 1_0, as understood relative to the definitions for some wireless communication systems.

[0036] This type of PRACH target cell information can be presented in different ways and according to different bit widths of the corresponding PRACH target cell information field. In the first option, the PRACH target cell information field is 1 bit. In this case, a single bit value representing the PRACH target cell information can correspond to either a serving cell configured as in the UE's active TCI state or a non-serving cell configured as in the UE's active TCI state. Therefore, the UE can apply the bit value with the active TCI state to identify / select either the serving cell or the non-serving cell as the PRACH target cell for the PDCCH command.

[0037] In the second option, the PRACH target cell information field is ceil(log2(N)) bits, where N is the number of one or more active non-serving cells at the UE. A non-serving cell can be understood at the UE as a set of Physical Cell Identities (PCIs) corresponding to those non-serving cells known to the UE (e.g., in some wireless communication systems, as one or more PCIs in multiple SSB-MTC-AdditionalPCI-r17 IEs configured in the AdditionalPCI-TOAddModList-17 IE at the UE). In such cases, the value represented by the PRACH target cell information can be an index value that the UE applies to that set of PCIs for one or more active non-serving cells to select a PCI from that set. This allows the UE to identify / select the non-serving cell corresponding to the PCI as the PRACH target cell for the PDCCH command.

[0038] In the third option, the PRACH target cell information field is ceil(log2(N) max )) bits, where N maxThis is the maximum number of configurable non-serving cells for the UE. This maximum value can be understood as the maximum number of a set of PCIs that can be configured at the UE for a non-serving cell (e.g., in some wireless communication systems, as the maximum number of one or more PCIs represented by the number of SSB-MTC-AdditionalPCI-r17 IEs that can be configured in the AdditionalPCI-TOAddModList-17 IE at the UE). In such cases, the value represented by the PRACH target cell information can be an index value that the UE applies to a set of PCIs corresponding to the maximum number of one or more active non-serving cells to select a PCI. This set of PCIs can be a (optionally) fully populated configuration representing the maximum number of possible active non-serving cells. It should be noted that since the network may not necessarily actually configure this maximum number of non-serving cells to the UE at a given time, the network can ensure that the index value provided in the PRACH target cell information corresponds to the PCI of the currently actually active non-serving cell. Knowing the PCI, the UE can therefore identify / select the non-serving cell corresponding to the PCI as the PRACH target cell for the PDCCH command.

[0039] It should be noted that in some cases, the maximum number of one or more non-serving cells that can be configured at the UE is seven. Therefore, in such cases, the PRACH target cell information field is ceil(log2(7)) = 3 bits.

[0040] In the fourth option, the PRACH target cell information field can be a number of bits sufficient to directly identify the PCI. In such cases, the PRACH target cell information may therefore identify the PCI of the intended PRACH target cell for the PDCCH command. Then, knowing the PCI, the UE can identify / select the cell corresponding to the PCI as the PRACH target cell for the PDCCH command. It should be noted that in these cases, the PRACH target cell (the cell corresponding to the indicated PCI) can be a serving cell or one of one or more non-serving cells.

[0041] It should be noted that in some wireless communication networks, the PCI can be represented by 10 bits. Therefore, in such networks, the PRACH target cell information field may be 10 bits long. Thus, when the PCI is received as PRACH target cell information in this field, the UE can identify / select the cell corresponding to the PCI as the PRACH target cell for the PDCCH command.

[0042] In some implementations, within an inter-cell mTRP context using two TAGs with independent TAs, when a PRACH target cell information field with PRACH target cell information is introduced into the DCI of a PDCCH command to support triggering PRACH transmissions toward neighboring cells (e.g., as described herein), if the bit width of the PRACH target information field is X bits, then X bits are reduced based on the number of reserved bits that may exist in the DCI in some wireless communication systems. For example, in some wireless communication networks, this might mean that the DCI carries 12-X reserved bits for shared spectrum in FR1 or for a common search space for FR2-2 (e.g., above 52.6 GHz), and otherwise carries 10-X reserved bits.

[0043] In some implementations, within an inter-cell mTRP context using two TAGs with independent TAs, when a PRACH target cell information field with PRACH target cell information is introduced in the DCI of the PDCCH command to support triggering PRACH transmission toward a neighboring cell (e.g., as described herein), it is possible to use a pre-configured value to indicate the serving cell. For example, in a first option, a binary all-zero value in the PRACH target cell information field can be used to indicate the serving cell. As another example, in a second option, a binary all-one value in the PRACH target cell information field can be used to indicate the serving cell. Upon receiving the pre-configured value, the UE therefore understands that it will select the serving cell as the PRACH target cell.

[0044] In some implementations, within an inter-cell mTRP context using two TAGs with independent TAs, the UE may provide capability information to the network indicating the maximum number of non-serving cells the UE can support as identifiable PRACH target cells relative to a PDCCH command that triggers PRACH transmission toward neighboring cells in the PDCCH command. This number can be interpreted by the network as the maximum number of non-serving cells supported at the UE as identifiable PRACH target cells other than serving cells (e.g., as described herein, which may also be identified as PRACH target cells in at least some cases). It should be noted that this capability (for the maximum number of non-serving cells the UE can support as identifiable PRACH target cells relative to a PDCCH command that triggers PRACH transmission toward neighboring cells in the PDCCH command) can also be used to determine / control the bit width of the PRACH target cell information field.

[0045] In some implementations, various power control aspects can be implemented within an inter-cell mTRP context using two TAGs with independent TAs. For example, when an SSB associated with a PRACH transmission corresponds to a serving cell, or when an SSB serving as a quasi-co-located (QCL) source of a Channel State Information Reference Signal (CSI-RS) associated with a PRACH transmission corresponds to a serving cell, the UE can determine the SSB power level of that SSB by referring to the SSB power level configured for that SSB in one of the ServingCellConfigCommon IE, ServingCellConfigCommonSIB IE, and / or SSB-Configuration-r16 IE. The UE can then perform corresponding power control calculations for PRACH transmissions on the serving cell based on the SSB power level (e.g., it can use a path loss value for the SSB, which is determined relative to the SSB power level).

[0046] Furthermore, when the SSB associated with a PRACH transmission corresponds to a non-serving cell, or when the SSB that serves as the QCL source for the CSI-RS associated with a PRACH transmission corresponds to a non-serving cell, the UE may determine the SSB power level of the SSB by referring to the SSB power level in the ss-PBCH-BlockPower IE configured in the SSB-MTC-AdditionalPCI-r17 IE for the non-serving cell indicated to the UE by the network. The UE can then perform corresponding power control calculations for PRACH transmissions on the non-serving cell based on the SSB power level (e.g., it may use a path loss value for the SSB, which is determined relative to the SSB power level).

[0047] Implementation scheme for RACH operation triggered by UE

[0048] In some implementations, within an inter-cell mTRP or intra-cell mTRP context using two TAGs with independent TAs, the network can configure a list of SSBs and / or CSI-RSs for each TAG via Radio Resource Control (RRC) signaling. CSI-RSs can be identified in the RRC signaling via NZP-CSI-RS-ResourceId IE. SSBs can be identified in the RRC signaling via SSB-Index IE, and additionally by PCI.

[0049] It can be assumed that each SSB / CSI-RS associated with the same TAG provides the same DL reference timing for UL operations based on the associated TAG. It should be noted that if the provided SSB / CSI-RS is not explicitly associated with a TAG in the RRC signaling, it can be assumed that the SSB / CSI-RS is associated with the first TAG (e.g., relative to the order in which the two TAGs appear in the RRC signaling).

[0050] In some implementations, within an inter-cell mTRP or intra-cell mTRP context using two TAGs with independent TAs, for each TAG, when the network configures a list of SSBs and / or CSI-RSs for each TAG using RRC signaling (e.g., as described herein), any SSB associated with the same PCI can be understood as configured in the same TAG. Furthermore, assuming that the QCL source of one or more CSI-RSs can be one or more SSBs, any CSI-RS with quasi-co-located (QCL'd) SSBs associated with the same PCI may also be understood as configured in the same TAG.

[0051] In an implementation of contention-based random access (CBRA) using a four-step RACH operation in an inter-cell multi-TRP context with two TAGs having independent TAs, as part of the inter-cell mTRP operation, it is possible to provide the UE for the non-serving cell with multiple SSBs per RO for the non-serving cell and multiple contention-based preambles per SSB for the non-serving cell (e.g., in the ssb-perRACH-OccasionAndCB-PreamblesPerSSB IE for the non-serving cell in the RACH-ConfigCommon IE). Therefore, it is understood that in some implementations, a first information element and a second information element may be provided to the UE, the first information element indicating, for the CBRA, a first number of SSBs per RO for the serving cell and a first number of contention-based preambles per SSB for the serving cell (e.g., a first ssb-perRACH-OccasionAndCB-PreamblesPerSSBIE for the serving cell in RACH-ConfigCommon IE), and the second information element indicating, for the CBRA, a second number of SSBs per RO for the non-serving cell and a second number of contention-based preambles per SSB for the non-serving cell (e.g., a second ssb-perRACH-OccasionAndCB-PreamblesPerSSB IE for the non-serving cell in RACH-ConfigCommon IE). The first number of SSBs per RO for the serving cell and the first number of contention-based preambles per SSB for the serving cell can therefore be used by the UE to identify the RO for the serving cell in a multi-TRP context, while the second number of SSBs per RO for the non-serving cell and the second number of contention-based preambles per SSB for the non-serving cell can therefore be used by the UE to identify the RO for the non-serving cell in a multi-TRP context.

[0052] In the case of a second number of SSBs per RO for a non-serving cell and a second number of contention-based preambles per SSB for a non-serving cell, PCI can also be included in the configuration corresponding to this configuration (e.g., in the second ssb-perRACH-OccasionAndCB-PreamblesPerSSB IE for a non-serving cell), thereby enabling the UE to identify the non-serving cell.

[0053] In an implementation of CBRA using a four-step RACH operation in an inter-cell multi-TRP context with two TAGs having independent TAs, as part of the inter-cell multi-TRP operation, it is possible to provide the UE for the non-serving cell with an index (e.g., in the prach-RootSequenceIndex IE for the non-serving cell) for the RACH operation to generate a preamble for the RACH operation corresponding to a reference signal in the reference signal list for the non-serving cell. Therefore, it is understood that in some implementations, a first information element and a second information element may be provided to the UE. The first information element indicates, in relation to the CBRA, a first sequence for generating a first preamble corresponding to a first reference signal in a first reference signal list for the serving cell (e.g., for the first prach-RootSequenceIndex IE of the serving cell in the RACH-ConfigCommon IE), and the second information element indicates, in relation to the CBRA, a second sequence for generating a second preamble corresponding to a second reference signal in a second reference signal list for the serving cell (e.g., in the second prach-RootSequenceIndex IE of a non-serving cell in the RACH-ConfigCommon IE). The first sequence can thus be used by the UE to generate a preamble for the first RACH operation on the serving cell, and the second sequence can thus be used by the UE to generate a preamble for the second RACH operation on a non-serving cell.

[0054] In implementations of contention-free random access (CFRA) using two-step RACH or four-step RACH operations in an inter-cell multi-TRP context with two TAGs having independent TAs, the network may provide the UE with an IE (e.g., a CRFA-SSB-Resource IE) that includes an index for the sequence to be used to generate a preamble for CFRA. In some cases, if the network wants to use the index to identify the sequence for generating such a preamble for a non-serving cell, the network may also include the PCI of the non-serving cell in the IE (e.g., in an additional PCI IE). Where the index is intended to identify the sequence for generating such a preamble for the serving cell, the network may omit the PCI, and the UE may assume, based on this omission, that the index is intended for generating a preamble on the serving cell.

[0055] Figure 2An example is illustrated by an IE 200 (e.g., a ra-PreambleIndex IE as illustrated) that includes an index 202 to identify the sequence to be used for generating a preamble for CFRA. Additionally, as illustrated, the IE 200 also includes a PCI 204 (e.g., an additional PCI IE as illustrated) to identify the PCI of the cell to which the index 202 is used.

[0056] In implementations of CFRA using a four-step RACH operation in an inter-cell multi-TRP context with two TAGs having independent TAs, as part of the inter-cell multi-TRP operation, it is possible to provide the UE with the number of SSBs per RO for the non-serving cell (e.g., in the ssb-perRACH-Occasion IE for the non-serving cell in the RACH-ConfigDedicated IE). Therefore, it is understood that in some implementations, a first information element and a second information element may be provided to the UE, the first information element indicating a first number of SSBs per RO for the serving cell in relation to CFRA (e.g., in the first ssb-perRACH-Occasion IE for the non-serving cell in the RACH-ConfigDedicated IE), and the second information element indicating a second number of SSBs per RO for the non-serving cell in relation to CFRA (e.g., in the second ssb-perRACH-Occasion IE for the non-serving cell in the RACH-ConfigDedicated IE). (In IE). The first number of SSBs per RO for the serving cell can therefore be used by the UE to identify the RO for the serving cell in the multi-TRP context, while the second number of SSBs per RO for the non-serving cell can therefore be used by the UE to identify the RO for the non-serving cell in the multi-TRP context.

[0057] In implementations using two-step RACH operations against CBRA in an inter-cell multi-TRP context with two TAGs having independent TAs, independent configurations for each cell can be provided (e.g., a first independent configuration for the serving cell and a second independent configuration for the non-serving cell (e.g., in RACH-ConfigCommonTwoStepRA IE)). For RO configurations, these independent configurations may include one or more of the following: information elements indicating the number of synchronization SSBs per RO for the two-step RACH operation against CBRA and the number of contention-based preambles per SSB for the two-step RACH operation against the corresponding cell (e.g., msgA-SSB-PerRACH-OccasionAndCB-PreamblesPerSSB-r16 IE for the corresponding cell); and information elements indicating the number of contention-based preambles per SSB for the two-step RACH operation against CBRA (e.g., msgA-CB-PreamblesPerSSB-PerSharedRO-r16 for the corresponding cell). IE); and / or information elements for CBRA indicating a subset of four-step RACH operation ROs available in a two-step RACH operation for the corresponding cell (e.g., msgA-SSB-SharedRO-MaskIndex-r16IE for the corresponding cell).

[0058] In addition, for RACH sequence configuration, each independent configuration in the cell-specific configuration may include an IE that indicates the index of the sequence to be used to generate the preamble for the two-step RACH operation for the reference signal in the reference signal list corresponding to the corresponding cell (e.g., msgA-PRACH-RootSequenceIndex-r16 IE for the corresponding cell).

[0059] In implementations of CFRA using two-step RACH operations in an inter-cell multi-TRP context with two TAGs having independent TAs, as part of the inter-cell multi-TRP operation, it is possible to provide the UE with the number of SSBs per RO for the non-serving cell (e.g., in the ssb-PerRACH-OccasionTwoStepRA-r16 IE for the non-serving cell in CFRA-TwoStep-r16 IE). Therefore, it is understood that in some implementations, the UE may be provided with a first information element indicating a first number of SSBs per RO for the serving cell in CFRA (e.g., in the first ssb-PerRACH-OccasionTwoStepRA-r16 IE for the serving cell in CFRA-TwoStep-r16 IE) and a second information element indicating a second number of SSBs per RO for the non-serving cell in CFRA (e.g., in the second ssb-PerRACH-OccasionTwoStepRA-r16 IE for the non-serving cell in CFRA-TwoStep-r16 IE). The first number of SSBs per RO for the serving cell can therefore be used by the UE to identify the RO for the serving cell relative to the applicable SSB in a multi-TRP context, while the second number of SSBs per RO for the non-serving cell can therefore be used by the UE to identify the RO for the non-serving cell relative to the applicable SSB in a multi-TRP context.

[0060] In some implementations, various power control aspects can be implemented within an inter-cell mTRP context using two TAGs with independent TAs. For example, when an SSB associated with a PRACH transmission corresponds to a serving cell, or when an SSB that serves as the QCL source for a CSI-RS associated with a PRACH transmission corresponds to a serving cell, the UE can determine the power level of the SSB by referring to the SSB power level configured in the ss-PBCH-BlockPower IE in one of the ServingCellConfigCommon IE, ServingCellConfigCommonSIB IE, and / or SSB-Configuration-r16 IE. The UE can then perform corresponding power control calculations for PRACH transmissions on the serving cell based on the SSB power level (e.g., it can use a path loss value for the SSB, which is determined relative to the SSB power level).

[0061] Furthermore, when the SSB associated with a PRACH transmission corresponds to a non-serving cell, or when the SSB that serves as the QCL source for the CSI-RS associated with a PRACH transmission corresponds to a non-serving cell, the UE may determine the SSB power level of the SSB by referring to the SSB power level in the ss-PBCH-BlockPower IE configured in the SSB-MTC-AdditionalPCI-r17 IE for the non-serving cell indicated to the UE by the network. The UE can then perform corresponding power control calculations for PRACH transmissions on the non-serving cell based on the SSB power level (e.g., it may use a path loss value for the SSB, which is determined relative to the SSB power level).

[0062] Figure 3 A method 300 for a UE according to an embodiment of this document is illustrated. Method 300 includes receiving a DCI 302 from a network, the DCI including a PDCCH command for performing a PRACH transmission and PRACH target cell information. Method 300 further includes selecting a PRACH target cell from a serving cell and one or more non-serving cells based on the PRACH target cell information 304. Method 300 further includes transmitting a PRACH transmission 306 to the PRACH target cell to the network.

[0063] In some implementations of method 300, the PRACH target cell information includes a bit value, each of the serving cell and a first non-serving cell from one or more non-serving cells being configured in the UE’s active TCI state, and selecting the PRACH target cell based on the PRACH target cell information includes applying the bit value together with the active TCI state to select one of the serving cell and the first non-serving cell as the PRACH target cell.

[0064] In some implementations of method 300, the PRACH target cell information includes an index value, the one or more non-serving cells including one or more active non-serving cells at the UE, and selecting a PRACH target cell based on the PRACH target cell information includes: applying the index value to a set of PCIs for the one or more active non-serving cells to identify a first PCI from the set of PCIs; and using the first PCI to identify the first non-serving cell among the one or more active non-serving cells as the PRACH target cell.

[0065] In some implementations of method 300, the PRACH target cell information includes an index value, the one or more non-serving cells including one or more configurable non-serving cells for the UE, and selecting a PRACH target cell based on the PRACH target cell information includes: applying the index value to a set of one or more PCIs for the one or more configurable non-serving cells to identify a first PCI from the set of PCIs; and using the first PCI to identify a first non-serving cell among the one or more configurable non-serving cells as the PRACH target cell.

[0066] In some implementations of method 300, the PRACH target cell information includes the PCI of the PRACH target cell, and selecting the PRACH target cell based on the PRACH target cell information includes using the PCI to identify the PRACH target cell.

[0067] In some implementations of method 300, the PRACH target cell information includes a pre-configured value corresponding to the serving cell, and selecting the PRACH target cell based on the PRACH target cell information includes selecting the serving cell as the PRACH target cell based on the pre-configured value.

[0068] In some implementations, method 300 further includes transmitting capability information to the network, which indicates the maximum number of one or more non-serving cells supported by the UE as identifiable PRACH target cells.

[0069] In some implementations of method 300, the PRACH target cell includes a first non-serving cell among one or more non-serving cells, and further includes performing power control calculations for PRACH transmissions based on the SSB power level indicated by the network for the first non-serving cell.

[0070] Figure 4 A method 400 for a RAN according to an embodiment of this document is illustrated. Method 400 includes transmitting a DCI 402 to a UE, the DCI including a PDCCH command for performing PRACH transmission and PRACH target cell information identifying one of the UE's serving cell and one or more non-serving cells of the UE as the PRACH target cell. Method 400 also includes receiving a PRACH transmission from the UE to the PRACH target cell 404.

[0071] In some implementations of method 400, each of the serving cell and the first non-serving cell of one or more non-serving cells is configured in the UE’s active TCI state, and the PRACH target cell information includes a bit value indicating the serving cell and the first non-serving cell configured in the active TCI state as the PRACH target cell.

[0072] In some embodiments of method 400, one or more non-serving cells include one or more active non-serving cells at the UE, and the PRACH target cell information includes an index value of a first PCI identified from a set of PCIs for one or more active non-serving cells, the first PCI corresponding to the PRACH target cell.

[0073] In some embodiments of method 400, one or more non-serving cells include one or more configurable non-serving cells for the UE, and the PRACH target cell information includes an index value of a first PCI identified from a set of PCIs for one or more configurable non-serving cells, the first PCI corresponding to the PRACH target cell.

[0074] In some implementations of method 400, the PRACH target cell information includes the PCI of the PRACH target cell.

[0075] In some implementations of method 400, the PRACH target cell information includes pre-configured values ​​corresponding to the serving cell.

[0076] In some implementations, method 400 further includes receiving capability information from the UE, which indicates the maximum number of one or more non-serving cells supported by the UE as identifiable PRACH target cells.

[0077] Figure 5 A method 500 for a UE according to an embodiment herein is illustrated. Method 500 includes receiving 502 a first reference signal list for a first TAG and a second reference signal list for a second TAG from a network. Method 500 further includes identifying 504 a first RO corresponding to the first TAG based on the timing of the first reference signals in the first reference signal list. Method 500 further includes initiating 506 a first RACH operation to the network using the first RO.

[0078] In some implementations, method 500 further includes identifying a second RO corresponding to a second TAG based on the timing of a second reference signal in a second reference signal list; and using the second RO to initiate a second RACH operation to the network.

[0079] In some implementations of method 500, the first reference signal list includes SSB.

[0080] In some implementations of method 500, the first list of reference signals includes CSI-RS.

[0081] In some embodiments of method 500, the first reference signal list includes one or more first reference signals corresponding to a first PCI of the first cell, and the second reference signal list includes one or more second reference signals corresponding to a second PCI of the second cell, the second PCI being different from the first PCI.

[0082] In some implementations of method 500, one of the first TAG and the second TAG is associated with the serving cell of the UE, and the other of the first TAG and the second TAG is associated with the non-serving cell of the UE.

[0083] In some such implementations, method 500 further includes receiving a first information element and a second information element from the network, the first information element indicating, for the CBRA, a first number of SSBs per RO for the serving cell and a first number of contention-based preambles per SSB for the serving cell, and the second information element indicating, for the CBRA, a second number of SSBs per RO for the non-serving cell and a second number of contention-based preambles per SSB for the non-serving cell.

[0084] In some such implementations, the second information element also includes PCI for non-serving cells.

[0085] In some such embodiments, method 500 further includes receiving a first information element and a second information element from the network, the first information element indicating, for CBRA, a first index for a first sequence of a first preamble to be used for generating a first RACH operation for a first reference signal corresponding to a first reference signal in a first reference signal list, and the second information element indicating, for CBRA, a second index for a second sequence of a second preamble to be used for generating a second RACH operation for a second reference signal corresponding to a second reference signal in a second reference signal list.

[0086] In some such implementations, method 500 further includes receiving information elements from the network that indicate: an index for the sequence to be used to generate a preamble for the CFRA on a non-serving cell and the PCI of the non-serving cell.

[0087] In some such implementations, method 500 further includes receiving a first information element and a second information element from the network, the first information element indicating, in relation to the CFRA, a first number of SSBs per RO for the serving cell, and the second information element indicating, in relation to the CFRA, a second number of SSBs per RO for the non-serving cell.

[0088] In some such implementations, method 500 further includes receiving one or more of the following from the network for a non-serving cell: a first information element indicating, for the CBRA, a first number of SSBs per RO for a two-step RACH operation and a first number of contention-based preambles per SSB for a two-step RACH operation; a second information element indicating, for the CBRA, a second number of contention-based preambles per SSB for a two-step RACH operation; a third information element indicating, for the CBRA, a subset of four-step RACH operation ROs available in the two-step RACH operation; and a fourth information element indicating, for the CBRA, an index for a sequence of preambles to be used to generate a two-step RACH operation for reference signals corresponding to reference signals for a non-serving cell in a first reference signal list and a second reference signal list.

[0089] In some such implementations, method 500 further includes receiving a first information element and a second information element from the network, the first information element indicating, in relation to the CFRA, a first number of SSBs per RO for two-step RACH operation for the serving cell, and the second information element indicating, in relation to the CFRA, a second number of SSBs per RO for two-step RACH operation for the non-serving cell.

[0090] In some such implementations, method 500 further includes performing power control calculations for PRACH transmissions of either a first RACH operation or a second RACH operation performed on the non-serving cell, based on the SSB power level indicated by the network for the non-serving cell.

[0091] Figure 6 A method 600 for a RAN according to an embodiment herein is illustrated. Method 600 includes transmitting 602 a first reference signal list for a first TAG and a second reference signal list for a second TAG to a UE. Method 600 also includes performing 604 a first RACH operation with the UE using a first RO corresponding to the first TAG, wherein the first RO corresponds to the timing of a first reference signal in the first reference signal list.

[0092] In some implementations, method 600 further includes performing a second RACH operation with the UE using a second RO corresponding to a second TAG, wherein the second RO corresponds to a timing of a second reference signal in a second list of reference signals.

[0093] In some implementations of method 600, the first reference signal list includes SSB.

[0094] In some implementations of method 600, the first list of reference signals includes CSI-RS.

[0095] In some embodiments of method 600, the first reference signal list includes one or more first reference signals corresponding to a first PCI of a first cell, and the second reference signal list includes one or more second reference signals corresponding to a second PCI of a second cell, the second PCI being different from the first PCI.

[0096] In some embodiments of method 600, one of the first TAG and the second TAG is associated with the serving cell of the UE, and the other of the first TAG and the second TAG is associated with the non-serving cell of the UE.

[0097] In some such implementations, method 600 further includes transmitting to the UE a first information element and a second information element, the first information element indicating, in relation to the CBRA, a first number of SSBs per RO for the serving cell and a first number of contention-based preambles per SSB for the serving cell, and the second information element indicating, in relation to the CBRA, a second number of SSBs per RO for the non-serving cell and a second number of contention-based preambles per SSB for the non-serving cell.

[0098] In some such implementations, the second information element also includes PCI for non-serving cells.

[0099] In some such embodiments, method 600 further includes transmitting to the UE a first information element and a second information element, the first information element indicating, for CBRA, a first index for a first sequence of a first preamble to be used for generating a first RACH operation corresponding to a first reference signal in a first reference signal list, and the second information element indicating, for CBRA, a second index for a second sequence of a second preamble to be used for generating a second RACH operation corresponding to a second reference signal in a second reference signal list.

[0100] In some such implementations, method 600 further includes transmitting an information element to the UE indicating: an index for the sequence to be used to generate a preamble for the CFRA on the non-serving cell and the PCI of the non-serving cell.

[0101] In some such implementations, method 600 further includes transmitting to the UE a first information element and a second information element, the first information element indicating, in relation to the CFRA, a first number of SSBs per RO for the serving cell, and the second information element indicating, in relation to the CFRA, a second number of SSBs per RO for the non-serving cell.

[0102] In some such implementations, method 600 further includes transmitting to the UE, for the non-serving cell, one or more of the following: a first information element indicating, for the CBRA, a first number of SSBs per RO for a two-step RACH operation and a first number of contention-based preambles per SSB for a two-step RACH operation; a second information element indicating, for the CBRA, a second number of contention-based preambles per SSB for a two-step RACH operation; a third information element indicating, for the CBRA, a subset of four-step RACH operation RACH timings available in the two-step RACH operation; and a fourth information element indicating, for the CBRA, an index for a sequence of preambles to be used to generate a two-step RACH operation for reference signals corresponding to reference signals for the non-serving cell in a first reference signal list and a second reference signal list.

[0103] In some such implementations, method 600 further includes transmitting to the UE a first information element and a second information element, the first information element indicating, in relation to the CFRA, a first number of SSBs per RO for two-step RACH operation for the serving cell, and the second information element indicating, in relation to the CFRA, a second number of SSBs per RO for two-step RACH operation for the non-serving cell.

[0104] Figure 7 An example architecture of a wireless communication system 700 according to an embodiment disclosed herein is illustrated. The following description is provided for an example wireless communication system 700 operating in conjunction with LTE system standards and / or 5G or NR system standards provided by 3GPP technical specifications.

[0105] like Figure 7 As shown, the wireless communication system 700 includes UE 702 and UE 704 (but any number of UEs may be used). In this example, UE 702 and UE 704 are exemplified 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.

[0106] UE 702 and UE 704 can be configured to be communicatively coupled to RAN 706. In an implementation, RAN 706 can be NG-RAN, E-UTRAN, etc. UE 702 and UE 704 utilize connections (or channels) with RAN 706 (shown as connection 708 and connection 710, respectively), where each connection (or channel) includes a physical communication interface. RAN 706 may include one or more base stations (such as base station 712 and base station 714) implementing connection 708 and connection 710.

[0107] In this example, Connection 708 and Connection 710 are air interfaces that enable this type of communication coupling and can conform to the RAT used by RAN706, such as LTE and / or NR, for example.

[0108] In some implementations, UE 702 and UE 704 can also exchange communication data directly via sidelink interface 716. UE 704 is shown configured to access an access point (shown as AP 718) via connection 720. By way of example, connection 720 may include a local wireless connection, such as a connection conforming to any IEEE 802.11 protocol, while AP 718 may include Wi-Fi. ® Router. In this example, AP 718 may connect to another network (e.g., the Internet) without using CN 724.

[0109] In the implementation, UE 702 and UE 704 may be configured to communicate with each other or with base station 712 and / or base station 714 on a multi-carrier communication channel using orthogonal frequency division multiplexing (OFDM) communication signals according to various communication technologies, such as, but not limited to, orthogonal frequency division multiple access (OFDMA) communication technology (e.g., for downlink communication) or single-carrier frequency division multiple access (SC-FDMA) communication technology (e.g., for uplink and ProSe or sidelink communication)). However, the scope of the implementation is not limited in this respect. The OFDM signal may include multiple orthogonal subcarriers.

[0110] In some implementations, all or part of base station 712 or base station 714 may be implemented as one or more software entities running on a server computer as part of a virtual network. Furthermore, or in other implementations, base station 712 or base station 714 may be configured to communicate with each other via interface 722. In implementations where wireless communication system 700 is an LTE system (e.g., when CN 724 is an EPC), interface 722 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 the EPC and / or between two eNBs connected to the EPC. In implementations where wireless communication system 700 is an NR system (e.g., when CN 724 is a 5GC), interface 722 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 the 5GC, between a base station 712 (e.g., a gNB) connected to the 5GC and an eNB, and / or between two eNBs connected to the 5GC (e.g., CN 724).

[0111] RAN 706 is shown communicatively coupled to CN 724. CN 724 may include one or more network elements 726 configured to provide various data and telecommunications services to customers / subscribers (e.g., users of UE 702 and UE 704) connected to CN 724 via RAN 706. Components of CN 724 may be implemented in a single physical device or a separate physical device, including components for reading and executing instructions from machine-readable or computer-readable media (e.g., non-transitory machine-readable storage media).

[0112] In the implementation scheme, CN 724 may be an EPC, and RAN 706 may be connected to CN 724 via S1 interface 728. In the implementation scheme, S1 interface 728 may be divided into two parts: an S1 user plane (S1-U) interface, which carries service data between base station 712 or base station 714 and the service gateway (S-GW); and an S1-MME interface, which is the signaling interface between base station 712 or base station 714 and the mobility management entity (MME).

[0113] In the implementation scheme, CN 724 may be a 5GC, and RAN 706 may be connected to CN 724 via NG interface 728. In the implementation scheme, NG interface 728 may be divided into two parts: an NG user plane (NG-U) interface, which carries service data between base station 712 or base station 714 and user plane function (UPF); and an S1 control plane (NG-C) interface, which is the signaling interface between base station 712 or base station 714 and access and mobility management function (AMF).

[0114] Generally, application server 730 can be a component that provides Internet Protocol (IP) carried resources (e.g., packet-switched data services) for use with CN 724. Application server 730 can also be configured to support one or more communication services (e.g., VoIP sessions, group communication sessions, etc.) for UE 702 and UE 704 via CN 724. Application server 730 can communicate with CN 724 via IP communication interface 732.

[0115] Figure 8 A system 800 for performing signaling 834 between a wireless device 802 and a network device 818 according to an embodiment disclosed herein is illustrated. System 800 may be part of a wireless communication system as described herein. Wireless device 802 may be, for example, a UE (User Equipment) in a wireless communication system. Network device 818 may be, for example, a base station (e.g., an eNB or gNB) in a wireless communication system.

[0116] Wireless device 802 may include one or more processors 804. Processor 804 may execute instructions to perform various operations of wireless device 802 as described herein. Processor 804 may include one or more baseband processors, which may be implemented using, for example, a central processing unit (CPU), digital signal processor (DSP), application-specific integrated circuit (ASIC), controller, field-programmable gate array (FPGA) device, another hardware device, firmware device, or any combination thereof configured to perform the operations described herein.

[0117] Wireless device 802 may include memory 806. Memory 806 may be a non-transitory computer-readable storage medium that stores instructions 808, which may include, for example, instructions executed by processor 804. Instructions 808 may also be referred to as program code or a computer program. Memory 806 may also store data used by processor 804 and results calculated by the processor.

[0118] Wireless device 802 may include one or more transceivers 810, which may include radio frequency (RF) transmitter circuitry and / or receiver circuitry that uses antenna 812 of wireless device 802 to facilitate signaling (e.g., signaling 834) to and / or from wireless device 802 and other devices (e.g., network device 818) in accordance with corresponding RAT.

[0119] Wireless device 802 may include one or more antennas 812 (e.g., one, two, four or more). In embodiments with multiple antennas 812, wireless device 802 may fully utilize the spatial diversity of these multiple antennas 812 to transmit and / or receive multiple different data streams on the same time-frequency resource. This behavior may be referred to as, for example, multiple-input multiple-output (MIMO) behavior (referring to multiple antennas used at each of the transmitting and receiving devices to implement this aspect). MIMO transmission by wireless device 802 may be implemented according to pre-decoding (or digital beamforming) applied to wireless device 802, which multiplexes the data streams among antennas 812 based on known or assumed channel characteristics, such that each data stream is received with appropriate signal strength relative to the other streams at a desired location in the spatial domain (e.g., the location of the receiver associated with that data stream). Some embodiments may use a single-user MIMO (SU-MIMO) method (where all data streams are directed to a single receiver) and / or a multi-user MIMO (MU-MIMO) method (where individual data streams may be directed to individual (different) receivers at different locations in the spatial domain).

[0120] In some implementations with multiple antennas, wireless device 802 can implement analog beamforming technology, whereby the phase of the signal transmitted by antenna 812 is relatively adjusted so that the (joint) transmission of antenna 812 can be directed (this is sometimes referred to as beam control).

[0121] Wireless device 802 may include one or more interfaces 814. Interfaces 814 can be used to provide input to or output to wireless device 802. For example, wireless device 802 (UE) may include interfaces 814 such as microphones, speakers, touchscreens, and buttons to allow users of the UE to make inputs and / or outputs to the UE. Other interfaces of such UEs may consist of transmitters, receivers, and other circuitry that allow the UE to communicate with other devices (e.g., in addition to the transceiver 810 / antenna 812 already described), and may be based on known protocols (e.g., Wi-Fi). ® ,Bluetooth ® (etc.) to perform the operation.

[0122] Wireless device 802 may include a multi-tag rach module 816. The multi-tag rach module 816 may be implemented via hardware, software, or a combination thereof. For example, the multi-tag rach module 816 may be implemented as a processor, circuitry, and / or instructions 808 stored in memory 806 and executed by processor 804. In some examples, the multi-tag rach module 816 may be integrated within processor 804 and / or transceiver 810. For example, the multi-tag rach module 816 may be implemented via a combination of software components (e.g., software components executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuitry) within processor 804 or transceiver 810.

[0123] The multi-tag rach module 816 can be used in various aspects of this disclosure, for example, Figures 1 to 6 All aspects. The multi-TAGRACH module 816 can be configured to generate RACHs on corresponding TAGs in multiple TAGs in the manner described herein using different TAs, such as those triggered by a PDCCH command and / or those triggered by a UE.

[0124] Network device 818 may include one or more processors 820. Processor 820 may execute instructions to perform various operations of network device 818 as described herein. Processor 820 may include one or more baseband processors, which may be implemented using, for example, a CPU, DSP, ASIC, controller, FPGA device, another hardware device, firmware device, or any combination thereof configured to perform the operations described herein.

[0125] Network device 818 may include memory 822. Memory 822 may be a non-transitory computer-readable storage medium that stores instructions 824, which may include, for example, instructions executed by processor 820. Instructions 824 may also be referred to as program code or a computer program. Memory 822 may also store data used by processor 820 and results calculated by the processor.

[0126] Network device 818 may include one or more transceivers 826, which may include RF transmitter circuitry and / or receiver circuitry that uses the antenna 828 of network device 818 to facilitate signaling (e.g., signaling 834) to and / or from network device 818 and other devices (e.g., wireless device 802) in accordance with the corresponding RAT.

[0127] Network device 818 may include one or more antennas 828 (e.g., one, two, four or more). In embodiments having multiple antennas 828, network device 818 may perform MIMO, digital beamforming, analog beamforming, beam control, etc., as described.

[0128] Network device 818 may include one or more interfaces 830. Interfaces 830 may be used to provide input to or output to network device 818. For example, network device 818 (base station) may include interfaces 830 consisting of transmitters, receivers, and other circuitry (e.g., in addition to the transceiver 826 / antenna 828 described), which enable the base station to communicate with other equipment in the core network and / or enable the base station to communicate with external networks, computers, databases, etc., for the purpose of performing operations, management, and maintenance of the base station or other equipment operatively connected to the base station.

[0129] Network device 818 may include a multi-tag rach module 832. The multi-tag rach module 832 may be implemented via hardware, software, or a combination thereof. For example, the multi-tag rach module 832 may be implemented as a processor, circuitry, and / or instructions 824 stored in memory 822 and executed by processor 820. In some examples, the multi-tag rach module 832 may be integrated within processor 820 and / or transceiver 826. For example, the multi-tag rach module 832 may be implemented via a combination of software components (e.g., software components executed by a DSP or general-purpose processor) and hardware components (e.g., logic gates and circuitry) within processor 820 or transceiver 826.

[0130] The multi-tag rach module 832 can be used in various aspects of this disclosure, for example, Figures 1 to 6All aspects. The multi-TAGRACH module 832 can be configured to generate and transmit PDCCH commands in the manner described herein, and / or receive RACH on corresponding TAGs in multiple TAGs using different TAs, such as those triggered by PDCCH commands and / or those triggered by the UE, in the manner described herein.

[0131] The embodiments contemplated herein include an apparatus comprising components for performing one or more elements of either method 300 or method 500. The apparatus may be, for example, a UE (such as wireless device 802 (UE), as described herein).

[0132] The embodiments contemplated herein include one or more non-transitory computer-readable media, the one or more non-transitory computer-readable media including instructions for causing the electronic device to perform one or more elements of any of the methods 300 and 500 when executed by one or more processors of the electronic device. The non-transitory computer-readable medium may be, for example, the memory of a UE (such as memory 806 of a wireless device 802 (UE), as described herein).

[0133] The embodiments contemplated herein include an apparatus comprising logic components, modules, or circuitry for performing one or more elements of either method 300 or method 500. The apparatus may be, for example, a UE (such as wireless device 802 (UE), as described herein).

[0134] The embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media including 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 300 or 500. The apparatus may be, for example, a UE (such as wireless device 802 (UE), as described herein).

[0135] The implementation scheme envisioned herein includes a signal as described or associated with one or more elements of either method 300 or method 500.

[0136] The embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution by a processor will cause the processor to perform one or more elements of any of method 300 and / or method 500. The processor may be a processor of the UE (such as processor 804 of wireless device 802 (UE), as described herein). These instructions may, for example, reside in the processor and / or in the memory of the UE (such as memory 806 of wireless device 802 (UE), as described herein).

[0137] The embodiments contemplated herein include an apparatus comprising components for performing one or more elements of either method 400 or method 600. This apparatus may be, for example, a base station (such as network device 818 (base station), as described herein).

[0138] The embodiments contemplated herein include one or more non-transitory computer-readable media, the one or more non-transitory computer-readable media including instructions for causing the electronic device to perform one or more elements of any of the methods 400 and 600 when executed by one or more processors of the electronic device. The non-transitory computer-readable medium may be, for example, the memory of a base station (such as memory 822 of network device 818 (base station), as described herein).

[0139] The embodiments contemplated herein include an apparatus comprising logic components, modules, or circuitry for performing one or more elements of either method 400 or method 600. The apparatus may be, for example, an apparatus for a base station (such as network device 818 (base station), as described herein).

[0140] The embodiments contemplated herein include an apparatus comprising: one or more processors and one or more computer-readable media including 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 400 or 600. The apparatus may be, for example, an apparatus for a base station (such as network device 818 (base station), as described herein).

[0141] The implementation scheme envisioned herein includes a signal as described or associated with one or more elements of either method 400 or method 600.

[0142] The embodiments contemplated herein include a computer program or computer program product comprising instructions, wherein execution of the program by a processing element will cause the processing element to perform one or more elements of either method 400 or method 600. The processor may be a processor of a base station (such as processor 820 of network device 818 (base station), as described herein). These instructions may, for example, reside in the processor and / or in the memory of the base station (such as memory 822 of network device 818 (base station), as described herein).

[0143] For one or more embodiments, at least one of the components set forth in one or more of the foregoing 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 foregoing figures may be configured to operate according to one or more of the examples set forth herein. Similarly, circuitry associated with a UE, base station, network element, etc., as described above in conjunction with one or more of the foregoing figures may be configured to operate according to one or more of the examples set forth herein.

[0144] 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 embodiments provides illustration and description, but is not intended to be exhaustive or to limit the scope of the embodiments to the precise form disclosed. In view of the teachings above, modifications and variations are possible, or modifications and variations may be derived from practice of various embodiments.

[0145] Implementations and specific embodiments of the systems and methods described herein may include various operations embodied in machine-executable instructions to be executed by a computer system. The computer system may include one or more general-purpose or special-purpose computers (or other electronic devices). The computer system may include hardware components, including specific logical parts for performing the operations; or may include a combination of hardware, software, and / or firmware.

[0146] It should be recognized that the systems described herein include descriptions of specific implementations. These implementations may be combined into a single system, partially integrated into other systems, divided into multiple systems, or otherwise partitioned or combined. Furthermore, it is contemplated that parameters, attributes, aspects, etc., of one implementation may be used in one implementation. For clarity, these parameters, attributes, aspects, etc., are described only in one or more implementations, and it should be recognized that, unless expressly stated herein, these parameters, attributes, aspects, etc., may be combined with or substituted for parameters, attributes, aspects, etc., of another implementation.

[0147] As is widely recognized, the use of personally identifiable information should comply with privacy policies and practices that are generally accepted to meet or exceed industry or governmental requirements for protecting 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 explained to users.

[0148] Although the foregoing has been described in considerable detail for clarity, it will be apparent that certain changes and modifications can be made without departing from the principles of the invention. It should be noted that many alternative ways exist to implement both the processes and apparatus described herein. Therefore, embodiments of the invention should be considered illustrative rather than restrictive, and this specification is not limited to the details given herein, but can be modified within the scope and equivalents of the appended claims.

Claims

1. A method for a user equipment (UE), the method comprising: Receive from the network a first reference signal list for a first timing advance group (TAG) and a second reference signal list for a second TAG; The timing of the first random access channel (RACH) corresponding to the first TAG is identified based on the timing of the first reference signal in the first reference signal list; and The first RO is used to initiate a first RACH operation to the network.

2. The method according to claim 1, further comprising: The second RO corresponding to the second TAG is identified based on the timing of the second reference signal in the second reference signal list; as well as The second RO is used to initiate a second RACH operation to the network.

3. The method of claim 1, wherein the first reference signal list includes a synchronization signal block (SSB).

4. The method according to claim 1, wherein the first reference signal list includes a channel state information reference signal (CSI-RS).

5. The method according to claim 1, wherein: The first reference signal list includes one or more first reference signals corresponding to the first physical cell identity (PCI) of the first cell; and The second reference signal list includes one or more second reference signals corresponding to the second PCI of the second cell, the second PCI being different from the first PCI.

6. The method of claim 1, wherein one of the first TAG and the second TAG is associated with the serving cell of the UE, and the other of the first TAG and the second TAG is associated with the non-serving cell of the UE.

7. The method of claim 6, further comprising receiving from the network: A first information element, indicating, for contention-based random access (CBRA), a first number of synchronization signal blocks (SSBs) per RO for the serving cell and a first number of contention-based preambles per SSB for the serving cell; and The second information element indicates, for the CBRA, a second number of SSBs per RO for the non-serving cell and a second number of contention-based preambles per SSB for the non-serving cell.

8. The method of claim 7, wherein the second information element further includes a physical cell identity (PCI) for the non-serving cell.

9. The method of claim 6, further comprising receiving from the network: A first information element, the first information element indicating a first index for a first sequence for a contention-based random access (CBRA) indication, the first sequence being used to generate a first preamble for a first RACH operation corresponding to a first reference signal in the first reference signal list; and The second information element indicates a second index for the second sequence in relation to the CBRA, the second sequence being used to generate a second preamble for a second RACH operation corresponding to a second reference signal in the second reference signal list.

10. The method of claim 6, further comprising receiving an information element from the network, the information element indicating the following: An index for a sequence used to generate a preamble for contention-free random access (CFRA) on the non-serving cell; and The Physical Cell Identity (PCI) of the non-serving cell.

11. The method of claim 6, further comprising receiving from the network: A first information element, indicating a first number of synchronization signal blocks (SSBs) per RO for the serving cell in relation to contention-free random access (CFRA); and The second information element indicates, with respect to the CFRA, a second number of SSBs per RO for the non-serving cell.

12. The method of claim 6, further comprising, for the non-serving cell, receiving one or more of the following from the network: The first information element indicates, for the purpose of contention-based random access (CBRA), a first number of synchronization signal blocks (SSBs) per RO for a two-step RACH operation and a first number of contention-based preambles per SSB for the two-step RACH operation. The second information element indicates, for the CBRA, a second number of contention-based preambles for each SSB used in the two-step RACH operation; The third information element is for the CBRA indicating a subset of the four-step RACH operation RO that can be used in the two-step RACH operation; as well as A fourth information element, the fourth information element being an index for a sequence indicated by the CBRA, the sequence being used to generate a preamble for the two-step RACH operation, the two-step RACH operation corresponding to a reference signal for the non-serving cell in one of the first reference signal list and the second reference signal list.

13. The method of claim 6, further comprising receiving from the network: The first information element indicates, for the purpose of Contention-Free Random Access (CFRA), a first number of synchronization signal blocks (SSBs) per RO for two-step RACH operation in the serving cell; and The second information element indicates, with respect to the CFRA, a second number of SSBs per RO for the two-step RACH operation in the non-serving cell.

14. The method of claim 6, further comprising performing power control calculations for physical random access channel (PRACH) transmissions of one of the first RACH operation and the second RACH operation performed on the non-serving cell based on a synchronization signal block (SSB) power level indicated by the network for the non-serving cell.

15. A method for a radio access network (RAN), the method comprising: Transmit to the User Equipment (UE) a first reference signal list for a first timing advance group (TAG) and a second reference signal list for a second TAG; as well as The UE performs a first RACH operation using a first random access channel (RACH) timing (RO) corresponding to the first TAG, wherein the first RO corresponds to the timing of a first reference signal in the first reference signal list.

16. The method of claim 15, further comprising performing a second RACH operation with the UE using a second RO corresponding to the second TAG, wherein the second RO corresponds to a timing of a second reference signal in the second reference signal list.

17. The method of claim 15, wherein the first reference signal list includes a synchronization signal block (SSB).

18. The method of claim 15, wherein the first reference signal list includes a channel state information reference signal (CSI-RS).

19. The method of claim 15, wherein: The first reference signal list includes one or more first reference signals corresponding to the first physical cell identity (PCI) of the first cell; and The second reference signal list includes one or more second reference signals corresponding to the second PCI of the second cell, the second PCI being different from the first PCI.

20. The method of claim 15, wherein one of the first TAG and the second TAG is associated with the serving cell of the UE, and the other of the first TAG and the second TAG is associated with the non-serving cell of the UE.

21. The method of claim 20, further comprising transmitting to the UE: A first information element, indicating, for contention-based random access (CBRA), a first number of synchronization signal blocks (SSBs) per RO for the serving cell and a first number of contention-based preambles per SSB for the serving cell; and The second information element indicates, for the CBRA, a second number of SSBs per RO for the non-serving cell and a second number of contention-based preambles per SSB for the non-serving cell.

22. The method of claim 21, wherein the second information element further includes a physical cell identity (PCI) for the non-serving cell.

23. The method of claim 20, further comprising transmitting to the UE: A first information element, the first information element indicating a first index for a first sequence for a contention-based random access (CBRA) indication, the first sequence being used to generate a first preamble for a first RACH operation corresponding to a first reference signal in the first reference signal list; and The second information element indicates a second index for the second sequence in relation to the CBRA, the second sequence being used to generate a second preamble for a second RACH operation corresponding to a second reference signal in the second reference signal list.

24. The method of claim 20, further comprising transmitting an information element to the UE, the information element indicating the following: An index for a sequence used to generate a preamble for contention-free random access (CFRA) on the non-serving cell; and The Physical Cell Identity (PCI) of the non-serving cell.

25. The method of claim 20, further comprising transmitting to the UE: A first information element, indicating a first number of synchronization signal blocks (SSBs) per RO for the serving cell in relation to contention-free random access (CFRA); and The second information element indicates, with respect to the CFRA, a second number of SSBs per RO for the non-serving cell.

26. The method of claim 20, further comprising transmitting one or more of the following to the UE for the non-serving cell: The first information element indicates, for the purpose of contention-based random access (CBRA), a first number of synchronization signal blocks (SSBs) per RO for a two-step RACH operation and a first number of contention-based preambles per SSB for the two-step RACH operation. The second information element indicates, for the CBRA, a second number of contention-based preambles for each SSB used in the two-step RACH operation; The third information element refers to a subset of the four-step RACH operation RACH timings that can be used in the two-step RACH operation, as indicated by the CBRA. as well as A fourth information element, the fourth information element being an index for a sequence indicated by the CBRA, the sequence being used to generate a preamble for the two-step RACH operation, the two-step RACH operation corresponding to a reference signal for the non-serving cell in one of the first reference signal list and the second reference signal list.

27. The method of claim 20, further comprising transmitting to the UE: The first information element indicates, for the purpose of Contention-Free Random Access (CFRA), a first number of synchronization signal blocks (SSBs) per RO for two-step RACH operation in the serving cell; and The second information element indicates, with respect to the CFRA, a second number of SSBs per RO for the two-step RACH operation in the non-serving cell.

28. An apparatus comprising components for performing the method according to any one of claims 1 to 27.

29. A computer-readable medium comprising instructions that, when executed by one or more processors of an electronic device, cause the electronic device to perform the method according to any one of claims 1 to 27.

30. An apparatus comprising a logic component, module, or circuit for performing the method according to any one of claims 1 to 27.

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