Cell access procedure

Abstract

In some example embodiments, a method can be provided that comprises receiving at least one indication that indicates a downlink carrier of a first cell of a network or a downlink carrier of at least one second cell of the network for receiving an access response, wherein the at least one indication is received prior to reception of an order to transmit an access signal; and monitoring for the access response on the downlink carrier indicated in the at least one indication.

Description

Technical Field

[0001] Various example embodiments relate to the field of wireless communication, and specifically to cell access procedures, particularly random access procedures. Background Technology

[0002] In the field of wireless communications, there are access procedures such as random access or random access channel (RACH) procedures, which can utilize a first cell (e.g., primary cell (PCell)) and a second cell (e.g., secondary cell (SCell)). However, (initial and / or subsequent) access procedures can increase latency, process complexity, and / or cell interdependence. Therefore, it may be beneficial, for example, to improve the access procedure, such as by affecting its overall latency, reducing complexity (especially process complexity), and / or reducing or minimizing interdependence, particularly between the first cell (e.g., PCell) and the second cell (e.g., SCell). Summary of the Invention

[0003] The subject matter of the independent claims is provided for several aspects. Other aspects, advantages, and / or features are defined in the dependent claims, the description, and / or drawings.

[0004] In particular, in combination with any of the exemplary embodiments described herein and / or related exemplary embodiments, a first example aspect can be provided, comprising: At least one processor; and At least one memory storing instructions that, when executed by the at least one processor, cause the device to perform at least the following: Determine the availability of at least one indication, which specifies: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response; and Access responses are monitored on a downlink carrier of a first cell or at least a second cell, based at least in part on the availability of at least one indication.

[0005] In one example embodiment, an apparatus is provided, particularly an apparatus according to a first example aspect described herein, wherein determining the availability of at least one indication includes determining whether at least one indication exists or does not exist.

[0006] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the availability of at least one indicated cell determines whether a first cell or at least one second cell will be selected for monitoring.

[0007] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the availability of at least one indicated cell determines whether a first cell or at least one second cell will be selected for monitoring.

[0008] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein the presence or absence of at least one indication determines or decides which of the first cell or at least one second cell should be selected or chosen for monitoring.

[0009] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the absence of at least one indication causes default monitoring behavior.

[0010] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein the apparatus is caused to perform at least the following: Determine that at least one indication exists; and Monitor response messages on at least one downlink carrier specified in the instruction.

[0011] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein at least one indication includes: an explicit identifier of a downlink carrier to be used for monitoring access responses.

[0012] In one example embodiment, also referred to as the first example aspect, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein determining the availability of at least one indication is part of processing a command for transmitting an access signal.

[0013] In one example embodiment, an apparatus is provided, particularly an apparatus according to a first example embodiment of a first example aspect, wherein the command for transmitting the access signal is a Physical Downlink Control Channel (PDCCH) command, and wherein the access signal is a Random Access Channel (RACH) preamble.

[0014] In one example embodiment, or a second example embodiment, which may also be referred to as the first example aspect, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein determining the availability of at least one indication is part of processing at least one configuration message.

[0015] In one example embodiment, an apparatus is provided, particularly an apparatus according to a second example embodiment of the first example aspect, wherein at least one configuration message is at least one of the following: At least one Radio Resource Control (RRC) message, At least one System Information Block (SIB), or At least one Media Access Control (MAC) control element (CE).

[0016] In one example embodiment, also referred to as a third example embodiment of the first example aspect, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein the apparatus is further caused to perform at least: Receive a command to send an access signal from a first cell or from at least one second cell.

[0017] In one example embodiment, also referred to as a fourth example embodiment of the first example aspect, an apparatus is provided, particularly an apparatus according to a third example embodiment of the first example aspect, wherein the apparatus is further caused to perform at least the following: Based at least in part on this command, the uplink carrier used to transmit the access signal is selected.

[0018] In one example embodiment, an apparatus is provided, particularly an apparatus according to a fourth example embodiment of the first example aspect, wherein the selection of an uplink carrier is performed based on an implicit mapping between a downlink carrier and a corresponding uplink carrier in which a command is received.

[0019] In one example embodiment, an apparatus is provided, particularly an apparatus according to a fourth example embodiment of the first example aspect, wherein the selection of an uplink carrier is performed based on an explicit identifier of the uplink carrier included in a command.

[0020] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein the apparatus is caused to perform at least the following: Send an access signal to the first cell or to at least one second cell.

[0021] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein the apparatus is caused to perform at least the following: If at least one indication exists or is available, monitor the access response on the downlink specified in at least one indication.

[0022] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein the apparatus is caused to perform at least the following: In the event that at least one indication is absent or missing, the access response is monitored on the downlink carrier of the first cell or at least one of the second cells that is the primary cell PCell.

[0023] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the access response includes a timing advance command (TAC) associated with at least one second cell.

[0024] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the access response is a Random Access Response (RAR) message.

[0025] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein at least one second cell and a first cell are associated with different timing advance TAs or different timing advance groups TAs.

[0026] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the apparatus is configured with at least one uplink carrier to at least one second cell and at least one uplink carrier to a first cell.

[0027] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein at least one second cell is a secondary cell SCell of the network.

[0028] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the first cell is the primary cell PCell of a network.

[0029] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspects and / or related example embodiments described herein, wherein the apparatus is a user equipment (UE), or wherein the apparatus is included in a UE.

[0030] Furthermore, particularly according to the first example aspect, an apparatus can be provided that includes components for the following: Determine the availability of at least one indication, which specifies: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response; and Access responses are monitored on a downlink carrier of a first cell or at least a second cell, based at least in part on the availability of at least one indication.

[0031] In one example embodiment, an apparatus is provided, particularly an apparatus according to a first example aspect described herein, wherein determining the availability of at least one indication includes determining whether at least one indication exists or does not exist.

[0032] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the availability of at least one indicated cell determines whether a first cell or at least one second cell will be selected for monitoring.

[0033] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the availability of at least one indicated cell determines whether a first cell or at least one second cell will be selected for monitoring.

[0034] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein the presence or absence of at least one indication determines or decides which of the first cell or at least one second cell will be selected or chosen for monitoring.

[0035] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the absence of at least one indication causes default monitoring behavior.

[0036] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein the component is configured to: Determine that at least one indication exists; and Monitor response messages on at least one downlink carrier specified in the instruction.

[0037] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein at least one indication includes: an explicit identifier of a downlink carrier to be used for monitoring access responses.

[0038] In one example embodiment, also referred to as the first example aspect, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein determining the availability of at least one indication is part of processing a command for transmitting an access signal.

[0039] In one example embodiment, an apparatus is provided, particularly an apparatus according to a first example embodiment of a first example aspect, wherein the command for transmitting the access signal is a Physical Downlink Control Channel (PDCCH) command, and wherein the access signal is a Random Access Channel (RACH) preamble.

[0040] In one example embodiment, or a second example embodiment, which may also be referred to as the first example aspect, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein determining the availability of at least one indication is part of processing at least one configuration message.

[0041] In one example embodiment, an apparatus is provided, particularly an apparatus according to a second example embodiment of the first example aspect, wherein at least one configuration message is at least one of the following: At least one Radio Resource Control (RRC) message, At least one System Information Block (SIB), or At least one Media Access Control (MAC) control element (CE).

[0042] In one example embodiment, also referred to as a third example embodiment of the first example aspect, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein the component is configured to: Receive a command to send an access signal from a first cell or from at least one second cell.

[0043] In one example embodiment, also referred to as a fourth example embodiment of the first example aspect, an apparatus is provided, particularly an apparatus according to a third example embodiment of the first example aspect, wherein the component is configured to: Based at least in part on this command, the uplink carrier used to transmit the access signal is selected.

[0044] In one example embodiment, an apparatus is provided, particularly an apparatus according to a fourth example embodiment of the first example aspect, wherein the selection of an uplink carrier is performed based on an implicit mapping between a downlink carrier and a corresponding uplink carrier in which a command is received.

[0045] In one example embodiment, an apparatus is provided, particularly an apparatus according to a fourth example embodiment of the first example aspect, wherein the selection of an uplink carrier is performed based on an explicit identifier of the uplink carrier included in a command.

[0046] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein the component is configured to: Send an access signal to the first cell or to at least one second cell.

[0047] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein the component is configured to: If at least one indication exists or is available, monitor the access response on the downlink specified in at least one indication.

[0048] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the first example aspect and / or related example embodiments described herein, wherein the component is configured to: In the event that at least one indication is absent or missing, the access response is monitored on the downlink carrier of the first cell or at least one of the second cells that is the primary cell PCell.

[0049] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the access response includes a timing advance command (TAC) associated with at least one second cell.

[0050] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the access response is a Random Access Response (RAR) message.

[0051] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein at least one second cell and a first cell are associated with different timing advance TAs or different timing advance groups TAs.

[0052] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the apparatus is configured with at least one uplink carrier to at least one second cell and at least one uplink carrier to a first cell.

[0053] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein at least one second cell is a secondary cell SCell of the network.

[0054] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, wherein the first cell is the primary cell PCell of a network.

[0055] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the first example aspects and / or related example embodiments described herein, wherein the apparatus is a user equipment (UE), or wherein the apparatus is included in a UE.

[0056] In the second example, a method may be provided that includes: Determine the availability of at least one indication, which specifies: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response; and Access responses are monitored on a downlink carrier of a first cell or at least a second cell, based at least in part on the availability of at least one indication.

[0057] In one example embodiment, a method is provided, particularly a method according to a second example aspect described herein, wherein determining the availability of at least one indication includes determining whether at least one indication exists or does not exist.

[0058] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the second example aspect and / or related example embodiments described herein, wherein the availability of at least one indicated cell determines whether a first cell or at least one second cell will be selected for monitoring.

[0059] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the second example aspect and / or related example embodiments described herein, wherein the availability of at least one indicated cell determines whether a first cell or at least one second cell will be selected for monitoring.

[0060] In one example embodiment, a method is provided, particularly a method according to any example embodiment of the second example aspect and / or related example embodiments described herein, wherein the presence or absence of at least one indication determines or decides which of the first cell or at least one second cell will be selected or chosen for monitoring.

[0061] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the second example aspect and / or related example embodiments described herein, wherein the absence of at least one indication causes default monitoring behavior.

[0062] In one example embodiment, a method is provided, particularly a method according to any example embodiment of the second example aspect and / or related example embodiments described herein, wherein the method includes: Determine that at least one indication exists; and Monitor response messages on at least one downlink carrier specified in the instruction.

[0063] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the second example aspect and / or related example embodiments described herein, wherein at least one indication includes: an explicit identifier of a downlink carrier to be used for monitoring access responses.

[0064] In one example embodiment, or also referred to as a first example embodiment of the second example aspect, a method is provided, particularly a method according to any example embodiment of the second example aspect and / or related example embodiments described herein, wherein determining the availability of at least one indication is part of processing a command for sending an access signal.

[0065] In one example embodiment, a method is provided, particularly the method according to the first example embodiment of the second example aspect, wherein the command for transmitting the access signal is a Physical Downlink Control Channel (PDCCH) command, and wherein the access signal is a Random Access Channel (RACH) preamble.

[0066] In one example embodiment, also referred to as a second example aspect, a method is provided, particularly a method according to any example embodiment of the second example aspect and / or related example embodiments described herein, wherein determining the availability of at least one indication is part of processing at least one configuration message.

[0067] In one example embodiment, a method is provided, particularly a method according to a second example embodiment of a second example aspect, wherein at least one configuration message is at least one of the following: At least one Radio Resource Control (RRC) message, At least one System Information Block (SIB), or At least one Media Access Control (MAC) control element (CE).

[0068] In one example embodiment, also referred to as a third example embodiment of the second example aspect, a method is provided, particularly a method according to any example embodiment of the second example aspect and / or related example embodiments described herein, wherein the method comprises: Receive a command to send an access signal from a first cell or from at least one second cell.

[0069] In one example embodiment, also referred to as a fourth example embodiment of the second example aspect, a method is provided, particularly a method according to a third example embodiment of the second example aspect, wherein the method includes: Based at least in part on this command, the uplink carrier used to transmit the access signal is selected.

[0070] In one example embodiment, a method is provided, particularly a method according to a fourth example embodiment of the second example aspect, wherein the selection of an uplink carrier is performed based on an implicit mapping between a downlink carrier and a corresponding uplink carrier in which a command is received.

[0071] In one example embodiment, a method is provided, particularly a method according to a fourth example embodiment of the second example aspect, wherein the selection of an uplink carrier is performed based on an explicit identifier of the uplink carrier included in a command.

[0072] In one example embodiment, a method is provided, particularly a method according to any example embodiment of the second example aspect and / or related example embodiments described herein, wherein the method includes: Send an access signal to the first cell or to at least one second cell.

[0073] In one example embodiment, a method is provided, particularly a method according to any example embodiment of the second example aspect and / or related example embodiments described herein, wherein the method includes: If at least one indication exists or is available, monitor the access response on the downlink specified in at least one indication.

[0074] In one example embodiment, a method is provided, particularly a method according to any example embodiment of the second example aspect and / or related example embodiments described herein, wherein the method includes: In the event that at least one indication is absent or missing, the access response is monitored on the downlink carrier of the first cell or at least one of the second cells that is the primary cell PCell.

[0075] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the second example aspect and / or related example embodiments described herein, wherein the access response includes a timing advance command (TAC) associated with at least one second cell.

[0076] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the second example aspect and / or related example embodiments described herein, wherein the access response is a Random Access Response (RAR) message.

[0077] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the second example aspect and / or related example embodiments described herein, wherein at least one second cell and a first cell are associated with different timing advance TAs or different timing advance groups TAs.

[0078] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the second example aspect and / or related example embodiments described herein, wherein the apparatus is configured with at least one uplink carrier to at least one second cell and at least one uplink carrier to a first cell.

[0079] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the second example aspect and / or related example embodiments described herein, wherein at least one second cell is a secondary cell SCell of the network.

[0080] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the second example aspect and / or related example embodiments described herein, wherein the first cell is the primary cell PCell of the network.

[0081] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the second example aspect and / or related example embodiments described herein, wherein the method is performed by or is operable by a device, wherein the device is a user equipment (UE), or wherein the device is included in the UE.

[0082] In a third example aspect, a non-transitory computer-readable storage medium may be provided, including program instructions that, when executed by a device, particularly a device according to any of the example embodiments of the first example aspect and / or related example embodiments described herein, cause operation including: Determine the availability of at least one indication, which specifies: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response; and Access responses are monitored on a downlink carrier of a first cell or at least a second cell, based at least in part on the availability of at least one indication.

[0083] The third example aspect may also include one or more steps and / or features of the method described in the second example aspect and / or any example embodiment of a related example embodiment.

[0084] In the fourth example aspect, which can be particularly combined with any of the example embodiments described herein and / or related example embodiments, an apparatus comprising: At least one processor; and At least one memory storing instructions that, when executed by the at least one processor, cause the device to perform at least the following: Receive at least one indication indicating: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response, wherein the at least one indication is received prior to the reception of a command for transmitting an access signal; and Monitor access responses on at least one downlink carrier specified in the indication.

[0085] In one example embodiment, or also referred to as the first example embodiment of the fourth example aspect, an apparatus is provided, particularly an apparatus according to the fourth example aspect described herein, wherein at least one indication is included in a configuration message received from a network.

[0086] In one exemplary embodiment, an apparatus is provided, particularly an apparatus according to a first exemplary embodiment of the fourth exemplary aspect described herein, wherein at least one indication is included in at least one of the following: Radio Resource Control (RRC) messages, System Information Block (SIB), or Media access control (MAC) control element.

[0087] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one indication is received via a downlink carrier specified in at least one indication.

[0088] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one indication is received from at least one second cell.

[0089] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one indication indicates that a downlink carrier of at least one second cell is used to receive a response message.

[0090] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one indication includes: an explicit identifier of a downlink carrier to be used to receive a response message.

[0091] In one exemplary embodiment, an apparatus is provided, particularly an apparatus according to any of the exemplary embodiments of the fourth exemplary aspect and / or related exemplary embodiments described herein, wherein the apparatus is further caused to perform at least: The monitoring command is based at least in part on at least one indication, on the downlink carrier of the first cell, or on the downlink carrier of at least one second cell.

[0092] In one exemplary embodiment, an apparatus is provided, particularly an apparatus according to any of the exemplary embodiments of the fourth exemplary aspect and / or related exemplary embodiments described herein, wherein the apparatus is further caused to perform at least: Receive a command to send an access signal from a first cell or from at least one second cell.

[0093] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one instruction and command is received from the same cell in a first cell or at least one second cell.

[0094] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the command is a Physical Downlink Control Channel (PDCCH) command.

[0095] In one example embodiment, also referred to as the second example embodiment of the fourth example aspect, an apparatus is provided, particularly an apparatus according to any example embodiment of the fourth example aspect and / or related example embodiments described herein, wherein the apparatus is further caused to perform at least: Send an access signal to the first cell or to at least one second cell.

[0096] In one example embodiment, an apparatus is provided, particularly an apparatus according to a second example embodiment of the fourth example aspect, wherein transmitting an access signal comprises: transmitting an access signal to a first cell or at least a second cell to which the apparatus receives at least one indication.

[0097] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the access signal is a Physical Random Access Channel (PRACH) preamble.

[0098] In one exemplary embodiment, an apparatus is provided, particularly an apparatus according to any of the exemplary embodiments of the fourth exemplary aspect and / or related exemplary embodiments described herein, wherein the apparatus is further caused to perform at least: The access response is received via a downlink carrier specified in at least one indication.

[0099] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the access response is a Random Access Response (RAR) message.

[0100] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the presence of at least one indication determines or decides which of the first cell or at least one second cell will be selected or chosen for monitoring.

[0101] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the access response includes a timing advance command (TAC) associated with at least one second cell.

[0102] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one second cell and a first cell are associated with different timing advance TAs or different timing advance groups TAs.

[0103] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the apparatus is configured with at least one uplink carrier to at least one second cell and at least one uplink carrier to a first cell.

[0104] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one second cell is a secondary cell SCell of the network.

[0105] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the first cell is the primary cell PCell of the network.

[0106] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the apparatus is a user equipment (UE), or wherein the apparatus is included in a UE.

[0107] Furthermore, particularly according to the fourth example aspect, an apparatus can be provided that includes components for the following: Receive at least one indication indicating: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response, wherein the at least one indication is received prior to the reception of a command for transmitting an access signal; and Monitor access responses on at least one downlink carrier specified in the indication.

[0108] In one example embodiment, or also referred to as the first example embodiment of the fourth example aspect, an apparatus is provided, particularly an apparatus according to the fourth example aspect described herein, wherein at least one indication is included in a configuration message received from a network.

[0109] In one exemplary embodiment, an apparatus is provided, particularly an apparatus according to a first exemplary embodiment of the fourth exemplary aspect described herein, wherein at least one indication is included in at least one of the following: Radio Resource Control (RRC) messages, System Information Block (SIB), or Media access control (MAC) control element.

[0110] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one indication is received via a downlink carrier specified in at least one indication.

[0111] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one indication is received from at least one second cell.

[0112] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one indication indicates that a downlink carrier of at least one second cell is used to receive a response message.

[0113] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one indication includes: an explicit identifier of a downlink carrier to be used to receive a response message.

[0114] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the fourth example aspect and / or related example embodiments described herein, wherein the component is configured to: The monitoring command is based at least in part on at least one indication, on the downlink carrier of the first cell or on the downlink carrier of at least one second cell.

[0115] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the fourth example aspect and / or related example embodiments described herein, wherein the component is configured to: Receive a command to send an access signal from a first cell or from at least one second cell.

[0116] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one instruction and command is received from the same cell in a first cell or at least one second cell.

[0117] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the command is a Physical Downlink Control Channel (PDCCH) command.

[0118] In one example embodiment, or also referred to as an example embodiment of the second example embodiment of the fourth example aspect, an apparatus is provided, particularly an apparatus according to any example embodiment of the fourth example aspect and / or related example embodiments described herein, wherein the component is configured to: Send an access signal to the first cell or to at least one second cell.

[0119] In one example embodiment, an apparatus is provided, particularly an apparatus according to a second example embodiment of the fourth example aspect, wherein transmitting an access signal comprises: transmitting an access signal to a first cell or at least a second cell to which the apparatus receives at least one indication.

[0120] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the access signal is a Physical Random Access Channel (PRACH) preamble.

[0121] In one example embodiment, an apparatus is provided, particularly an apparatus according to any example embodiment of the fourth example aspect and / or related example embodiments described herein, wherein the component is configured to: The access response is received via a downlink carrier specified in at least one indication.

[0122] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the access response is a Random Access Response (RAR) message.

[0123] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the presence of at least one indication determines or decides which of the first cell or at least one second cell will be selected or chosen for monitoring.

[0124] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the access response includes a timing advance command (TAC) associated with at least one second cell.

[0125] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one second cell and a first cell are associated with different timing advance TAs or different timing advance groups TAs.

[0126] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the apparatus is configured with at least one uplink carrier to at least one second cell and at least one uplink carrier to a first cell.

[0127] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein at least one second cell is a secondary cell SCell of the network.

[0128] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the first cell is the primary cell PCell of the network.

[0129] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, wherein the apparatus is a user equipment (UE), or wherein the apparatus is included in a UE.

[0130] In the fifth example aspect, which in particular can be combined with any of the example embodiments described herein and / or related example embodiments, a method comprising: Receive at least one indication indicating: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response, wherein the at least one indication is received prior to the reception of a command for transmitting an access signal; and Monitor access responses on at least one downlink carrier specified in the indication.

[0131] In one example embodiment, or also referred to as the first example embodiment of the fifth example aspect, a method is provided, particularly the method according to the fifth example aspect described herein, wherein at least one indication is included in a configuration message received from a network.

[0132] In one example embodiment, a method is provided, particularly a method according to a first example embodiment of the fifth example aspect described herein, wherein at least one indication is included in at least one of the following: Radio Resource Control (RRC) messages, System Information Block (SIB), or Media access control (MAC) control element.

[0133] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein at least one instruction is received via a downlink carrier specified in at least one instruction.

[0134] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein at least one indication is received from at least one second cell.

[0135] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein at least one indication specifies that a downlink carrier of at least one second cell is used to receive a response message.

[0136] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein at least one indication includes: an explicit identifier of a downlink carrier to be used to receive a response message.

[0137] In one example embodiment, a method is provided, particularly a method according to any example embodiment of the fifth example aspect and / or related example embodiments described herein, wherein the method includes: The monitoring command is based at least in part on at least one indication, on the downlink carrier of the first cell, or on the downlink carrier of at least one second cell.

[0138] In one example embodiment, a method is provided, particularly a method according to any example embodiment of the fifth example aspect and / or related example embodiments described herein, wherein the method includes: Receive a command to send an access signal from a first cell or from at least one second cell.

[0139] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein at least one instruction and command is received from the same cell in a first cell or at least one second cell.

[0140] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein the command is a Physical Downlink Control Channel (PDCCH) command.

[0141] In one example embodiment, also referred to as a second example embodiment of the fifth example aspect, a method is provided, particularly a method according to any example embodiment of the fifth example aspect and / or related example embodiments described herein, wherein the method comprises: Send an access signal to the first cell or to at least one second cell.

[0142] In one example embodiment, a method is provided, particularly the method according to the second example embodiment of the fifth example aspect, wherein transmitting an access signal comprises: transmitting an access signal to a first cell or at least a second cell to which the device receives at least one indication.

[0143] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein the access signal is a Physical Random Access Channel (PRACH) preamble.

[0144] In one example embodiment, a method is provided, particularly a method according to any example embodiment of the fifth example aspect and / or related example embodiments described herein, wherein the method includes: The access response is received via a downlink carrier specified in at least one indication.

[0145] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein the access response is a Random Access Response (RAR) message.

[0146] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein the presence of at least one indication determines or decides which of the first cell or at least one second cell will be selected or chosen for monitoring.

[0147] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein the access response includes a timing advance command (TAC) associated with at least one second cell.

[0148] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein at least one second cell and a first cell are associated with different timing advance TAs or different timing advance groups TAs.

[0149] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein the apparatus is configured with at least one uplink carrier to at least one second cell and at least one uplink carrier to a first cell.

[0150] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein at least one second cell is a secondary cell SCell of the network.

[0151] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein the first cell is the primary cell PCell of the network.

[0152] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the fifth example aspect and / or related example embodiments described herein, wherein the apparatus is a user equipment (UE), or wherein the apparatus is included in the UE.

[0153] In a sixth example aspect, a non-transitory computer-readable storage medium may be provided, including program instructions that, when executed by an apparatus, particularly an apparatus according to any of the example embodiments of the fourth example aspect and / or related example embodiments described herein, cause operation including: Receive at least one indication indicating: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response, wherein the at least one indication is received prior to the reception of a command for transmitting an access signal; and Monitor access responses on at least one downlink carrier specified in the indication.

[0154] The sixth example aspect may also include one or more steps and / or features of the method described in the fifth example aspect and / or any example embodiment of a related example embodiment.

[0155] In the seventh example aspect, which can be particularly combined with any example embodiment of the example aspects and / or related example embodiments described herein, an apparatus comprising: At least one processor; and At least one memory storing instructions that, when executed by the at least one processor, cause the device to at least perform: receiving a command for transmitting an access signal, wherein the command includes at least one indication indicating: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response; Monitor access responses on at least one downlink carrier specified in the indication.

[0156] In one example embodiment, an apparatus is provided, particularly an apparatus according to the seventh example aspect described herein, wherein the command is a downlink control message.

[0157] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the command is a Physical Downlink Control Channel (PDCCH) command.

[0158] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein a command is received via a downlink carrier specified in at least one instruction.

[0159] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein a command is received from at least one second cell.

[0160] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein at least one indication indicates that a downlink carrier of at least one second cell is used to receive an access response.

[0161] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein at least one indication includes: an explicit identifier of a downlink carrier to be used to receive an access response.

[0162] In one exemplary embodiment, also referred to as the first exemplary embodiment of the seventh exemplary aspect, an apparatus is provided, particularly an apparatus according to any exemplary embodiment of the seventh exemplary aspect and / or related exemplary embodiments described herein, wherein the apparatus is further caused to perform at least: The uplink carrier used for the transmission of access signals is selected, at least in part based on commands.

[0163] In one example embodiment, an apparatus is provided, particularly an apparatus according to a first example embodiment of the seventh example aspect described herein, wherein the selection of an uplink carrier is performed based on an implicit mapping between a downlink carrier and a corresponding uplink carrier in which a command is received.

[0164] In one example embodiment, an apparatus is provided, particularly an apparatus according to a first example embodiment of the seventh example aspect described herein, wherein the selection of an uplink carrier is performed based on an explicit identifier of the uplink carrier included in a command.

[0165] In one example embodiment, also referred to as the second example embodiment of the seventh example aspect, an apparatus is provided, particularly an apparatus according to any example embodiment of the seventh example aspect and / or related example embodiments described herein, wherein the apparatus is further caused to perform at least: Send an access signal to the first cell or to at least one second cell.

[0166] In one example embodiment, an apparatus is provided, particularly an apparatus according to a second example embodiment of the seventh example aspect described herein, wherein transmitting an access signal comprises: transmitting an access signal to a cell in a first cell or at least a second cell from which the apparatus receives a command.

[0167] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the access signal is a Physical Random Access Channel (PRACH) preamble.

[0168] In one exemplary embodiment, an apparatus is provided, particularly an apparatus according to the seventh exemplary aspect and / or any of the exemplary embodiments of the related exemplary embodiments described herein, wherein the apparatus is further caused to perform at least the following: The access response is received via a downlink carrier specified in at least one indication.

[0169] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the access response is a Random Access Response (RAR) message.

[0170] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the presence of at least one indication determines or decides which of the first cell or at least one second cell will be selected or chosen for monitoring.

[0171] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the access response includes a timing alignment associated with at least one second cell.

[0172] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the access response includes a timing advance command (TAC) associated with at least one second cell.

[0173] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the access response is a Random Access Response (RAR) message.

[0174] In one example embodiment, an apparatus is provided, particularly an apparatus according to the seventh example aspect and / or any of the example embodiments of the related example embodiments described herein, wherein at least one second cell and a first cell are associated with different timing advance TAs or different timing advance groups TAs.

[0175] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the apparatus is configured with at least one uplink carrier to at least one second cell and at least one uplink carrier to a first cell.

[0176] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein at least one second cell is a secondary cell SCell of the network.

[0177] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the first cell is the primary cell PCell of the network.

[0178] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the apparatus is a user equipment (UE), or wherein the apparatus is included in a UE.

[0179] Furthermore, particularly according to the seventh example aspect, an apparatus can be provided that includes components for the following: Receive a command for transmitting an access signal, wherein the command includes at least one indication indicating: a downlink carrier of a first cell of the network for receiving an access response or a downlink carrier of at least one second cell of the network; Monitor access responses on at least one downlink carrier specified in the indication.

[0180] In one example embodiment, an apparatus is provided, particularly an apparatus according to the seventh example aspect described herein, wherein the command is a downlink control message.

[0181] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the command is a Physical Downlink Control Channel (PDCCH) command.

[0182] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein a command is received via a downlink carrier specified in at least one instruction.

[0183] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein a command is received from at least one second cell.

[0184] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein at least one indication indicates that a downlink carrier of at least one second cell is used to receive an access response.

[0185] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein at least one indication includes: an explicit identifier of a downlink carrier to be used to receive an access response.

[0186] In one example embodiment, also referred to as the first example embodiment of the seventh example aspect, an apparatus is provided, particularly an apparatus according to any example embodiment of the seventh example aspect and / or related example embodiments described herein, wherein the component is configured to: The uplink carrier used for the transmission of access signals is selected, at least in part based on commands.

[0187] In one example embodiment, an apparatus is provided, particularly an apparatus according to a first example embodiment of the seventh example aspect described herein, wherein the selection of an uplink carrier is performed based on an implicit mapping between a downlink carrier on which a command is received and a corresponding uplink carrier.

[0188] In one example embodiment, an apparatus is provided, particularly an apparatus according to a first example embodiment of the seventh example aspect described herein, wherein the selection of an uplink carrier is performed based on an explicit identifier of the uplink carrier included in a command.

[0189] In one example embodiment, also referred to as a second example embodiment of the seventh example aspect, an apparatus is provided, particularly an apparatus according to any example embodiment of the seventh example aspect and / or related example embodiments described herein, wherein the component is configured to: Send an access signal to the first cell or to at least one second cell.

[0190] In one example embodiment, an apparatus is provided, particularly an apparatus according to a second example embodiment of the seventh example aspect described herein, wherein transmitting an access signal comprises: transmitting an access signal to a cell in a first cell or at least a second cell from which the apparatus receives a command.

[0191] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the access signal is a Physical Random Access Channel (PRACH) preamble.

[0192] In one exemplary embodiment, an apparatus is provided, particularly an apparatus according to the seventh exemplary aspect and / or any of the exemplary embodiments of the related exemplary embodiments described herein, wherein the component is configured to: The access response is received via a downlink carrier specified in at least one indication.

[0193] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the access response is a Random Access Response (RAR) message.

[0194] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the presence of at least one indication determines or decides which of the first cell or at least one second cell will be selected or chosen for monitoring.

[0195] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the access response includes a timing alignment associated with at least one second cell.

[0196] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the access response includes a timing advance command (TAC) associated with at least one second cell.

[0197] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the access response is a Random Access Response (RAR) message.

[0198] In one example embodiment, an apparatus is provided, particularly an apparatus according to the seventh example aspect and / or any of the example embodiments of the related example embodiments described herein, wherein at least one second cell and a first cell are associated with different timing advance TAs or different timing advance groups TAs.

[0199] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the apparatus is configured with at least one uplink carrier to at least one second cell and at least one uplink carrier to a first cell.

[0200] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein at least one second cell is a secondary cell SCell of the network.

[0201] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the first cell is the primary cell PCell of the network.

[0202] In one example embodiment, an apparatus is provided, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, wherein the apparatus is a user equipment (UE), or wherein the apparatus is included in a UE.

[0203] In the eighth example aspect, which in particular can be combined with any of the example embodiments described herein and / or related example embodiments, a method comprising: Receive a command for transmitting an access signal, wherein the command includes at least one indication indicating: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response; Monitor access responses on at least one downlink carrier specified in the indication.

[0204] In one example embodiment, a method is provided, particularly according to the eighth example aspect described herein, wherein the command is a downlink control message.

[0205] In one example embodiment, a method is provided, particularly a method according to the eighth example aspect and / or any of the example embodiments described herein and related example embodiments, wherein the command is a Physical Downlink Control Channel (PDCCH) command.

[0206] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the eighth example aspect and / or related example embodiments described herein, wherein a command is received via a downlink carrier specified in at least one indication.

[0207] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the eighth example aspect and / or related example embodiments described herein, wherein a command is received from at least one second cell.

[0208] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the eighth example aspect and / or related example embodiments described herein, wherein at least one indication specifies that a downlink carrier of at least one second cell is used to receive an access response.

[0209] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the eighth example aspect and / or related example embodiments described herein, wherein at least one indication includes: an explicit identifier of a downlink carrier to be used to receive an access response.

[0210] In one example embodiment, also referred to as the first example embodiment of the eighth example aspect, a method is provided, particularly a method according to any example embodiment of the eighth example aspect and / or related example embodiments described herein, wherein the method comprises: The uplink carrier used for the transmission of access signals is selected, at least in part based on commands.

[0211] In one example embodiment, a method is provided, particularly a method according to a first example embodiment of the eighth example aspect described herein, wherein the selection of an uplink carrier is performed based on an implicit mapping between a downlink carrier and a corresponding uplink carrier in which a command is received.

[0212] In one example embodiment, a method is provided, particularly a method according to a first example embodiment of the eighth example aspect described herein, wherein the selection of an uplink carrier is performed based on an explicit identifier of the uplink carrier included in a command.

[0213] In one example embodiment, also referred to as a second example embodiment of the eighth example aspect, a method is provided, particularly a method according to any example embodiment of the eighth example aspect and / or related example embodiments described herein, wherein the method comprises: Send an access signal to the first cell or to at least one second cell.

[0214] In one example embodiment, a method is provided, particularly a method according to a second example embodiment of the eighth example aspect described herein, wherein transmitting an access signal comprises: transmitting an access signal to a cell in a first cell from which the device receives a command, or to a cell in at least one second cell.

[0215] In one example embodiment, a method is provided, particularly a method according to the eighth example aspect and / or any of the example embodiments described herein and related example embodiments, wherein the access signal is a Physical Random Access Channel (PRACH) preamble.

[0216] In one example embodiment, a method is provided, particularly a method according to the eighth example aspect and / or any of the example embodiments of the relevant example embodiments described herein, wherein the method includes: The access response is received via a downlink carrier specified in at least one indication.

[0217] In one example embodiment, a method is provided, particularly a method according to the eighth example aspect and / or any of the example embodiments described herein and related example embodiments, wherein the access response is a random access response (RAR) message.

[0218] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the eighth example aspect and / or related example embodiments described herein, wherein the presence of at least one indication determines or decides which of the first cell or at least one second cell will be selected or chosen for monitoring.

[0219] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the eighth example aspect and / or related example embodiments described herein, wherein the access response includes timing alignment associated with at least one second cell.

[0220] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the eighth example aspect and / or related example embodiments described herein, wherein the access response includes a timing advance command (TAC) associated with at least one second cell.

[0221] In one example embodiment, a method is provided, particularly a method according to the eighth example aspect and / or any of the example embodiments described herein and related example embodiments, wherein the access response is a Random Access Response (RAR) message.

[0222] In one example embodiment, a method is provided, particularly a method according to the eighth example aspect and / or any of the example embodiments of the related example embodiments described herein, wherein at least one second cell and a first cell are associated with different timing advance TAs or different timing advance groups TAs.

[0223] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the eighth example aspect and / or related example embodiments described herein, wherein the apparatus is configured with at least one uplink carrier to at least one second cell and at least one uplink carrier to a first cell.

[0224] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the eighth example aspect and / or related example embodiments described herein, wherein at least one second cell is a secondary cell SCell of the network.

[0225] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the eighth example aspect and / or related example embodiments described herein, wherein the first cell is the primary cell PCell of the network.

[0226] In one example embodiment, a method is provided, particularly a method according to any of the example embodiments of the eighth example aspect and / or related example embodiments described herein, wherein the method is performed by or is performable by a device, wherein the device is a user equipment (UE), or wherein the device is included in the UE.

[0227] In the ninth example aspect, a non-transitory computer-readable storage medium may be provided, including program instructions that, when executed by an apparatus, particularly an apparatus according to any of the example embodiments of the seventh example aspect and / or related example embodiments described herein, cause operation including: Receive a command for transmitting an access signal, wherein the command includes at least one indication indicating: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response; Monitor access responses on at least one downlink carrier specified in the indication.

[0228] The ninth example aspect may also include one or more steps and / or features of the method described in the eighth example aspect and / or any of the example embodiments in the relevant example embodiments. Attached Figure Description

[0229] Some exemplary embodiments will now be described with reference to the accompanying drawings.

[0230] The remainder of this specification (including with reference to the accompanying drawings) sets forth in more detail a complete and enabling disclosure to a person skilled in the art, in which:

[0231] Figure 1 An example flowchart based on the topics described in this article is shown;

[0232] Figure 2 An example flowchart based on the topics described in this article is shown;

[0233] Figure 3 An example flowchart based on the topics described in this article is shown;

[0234] Figure 4 An example flowchart based on the topics described in this article is shown;

[0235] Figure 5 Example signaling based on the topics described in this article is shown; and

[0236] Figure 6 Example signaling based on the topics described in this article is shown. Detailed Implementation

[0237] Reference will now be made in detail to various embodiments, one or more examples of which are illustrated in the figures. In the following description of the figures, the same reference numerals may refer to the same components. Generally, differences may be described only with respect to individual embodiments. Each example is provided by way of interpretation and not by way of limitation. Furthermore, features shown or described as part of one embodiment may be used on or in combination with other embodiments to produce yet another embodiment. This specification is intended to include such modifications and variations.

[0238] These accompanying drawings are schematic and not drawn to scale. Some elements in the drawings may have exaggerated dimensions to highlight aspects of this disclosure and / or for clarity of presentation.

[0239] This disclosure particularly relates to a novel random access procedure, especially a novel (e.g., SCell) random access channel (RACH) procedure for carrier aggregation (CA), particularly when a first cell (e.g., primary cell (PCell)) and a second cell (e.g., secondary cell (SCell)) are not co-located, for example, located in different places, sites, etc.

[0240] "Random access" or "random access procedure" can be viewed as the process by which a device (e.g., a UE) intends to establish an (initial) connection with the network or network equipment. It can be called "random" because the device (e.g., the UE) does not yet have dedicated uplink resources. However, this allows the device (e.g., the UE) to request network resources to synchronize with network equipment and / or, for example, to re-establish communication after a connection loss. There can be two types of random access: i) contention-based random access (CBRA), where the UE can select a random access signal (e.g., a preamble, specifically a Physical Random Access Channel (PRACH) preamble) and transmit the random access signal; and ii) contention-free random access (CFRA), where the network can assign a dedicated access signal, such as a preamble, to the device (e.g., the UE).

[0241] A random access channel (RACH) can be considered a logical channel that a device (e.g., a UE) can use to send multiple random access requests to a network device. A physical random access channel (PRACH) can be considered a physical channel that can specifically carry RACH requests, for example, over the air. For example, a device (e.g., a UE) may initially not know its exact timing relative to the network. Therefore, it can send a preamble (e.g., a PRACH preamble) to allow the network to measure and / or correct its timing offset. The network can respond using an access response (e.g., a random access response (RAR)) to adjust the timing of the device (e.g., the UE). For example, the RAR may contain a timing advance command that instructs the device (e.g., the UE) how to adjust transmission timing in subsequent transmissions, etc. An access signal (e.g., a preamble) can be considered a specially designed signal sent by a device (e.g., the UE) to the network device, for example, when it wants to initiate a connection, request access, and / or request resources, etc. The preamble or PRACH preamble can be used for detection and / or timing estimation, and / or may include at least one sequence (e.g., a root sequence and at least one cyclic shift). The preamble may also include a guard period, such as a time interval that ensures the preamble does not interfere with subsequent transmissions. The RACH timing “RO” can be a time and / or frequency slot or block when a device (e.g., a UE) is permitted to send a random access request to, for example, a network device, and / or when the network device is listening for or anticipating a preamble (e.g., a PRACH preamble). In other words, the RO can be a specific region in the time and frequency domains where the network device can monitor, for example, a PRACH preamble from a device (e.g., a UE).

[0242] As described above, the Random Access Channel (RACH) can be an uplink channel used to initiate communication with the network. It can serve as an entry point for a device (e.g., a UE) to request resources, synchronize with the network, and / or establish a connection, particularly in scenarios such as initial access, handover, beam failure recovery, and / or reconnection after synchronization loss. As mentioned above, the random access procedure, especially the RACH procedure, can involve the device (e.g., the UE) sending an access signal, particularly a preamble, followed by an access response (particularly a Random Access Response (RAR)) from the network (particularly a base station), which may include timing alignment and / or resource allocation information. In a non-limiting example of fifth-generation (5G) networks, RACH has been further optimized with features such as beamforming support, flexible parameter sets, and / or two-step RACH procedures, particularly reducing latency and / or improving efficiency, especially in high-frequency and / or massive MIMO deployments. These advancements ensure reliable and / or low-latency connections, making RACH a cornerstone of modern wireless communication systems.

[0243] "Carrier aggregation" can refer to a technique used to combine or aggregate multiple frequency bands, carriers, or component carriers (CCs) into a single, larger bandwidth, for example, to provide higher data rates, better spectrum utilization, etc. In carrier aggregation (CA), the access or RACH procedure can be used to establish and / or maintain synchronization, particularly between a device (e.g., a UE) and the network, for example, across multiple component carriers (CCs). The access or RACH procedure can begin on a first cell (e.g., a primary cell (PCell)) that may carry system information and / or (multiple) synchronization signals. After the RACH procedure in the first cell (e.g., PCell) is successfully completed, one or more second cells (e.g., (multiple) secondary cells (SCells)) can be configured and / or activated, particularly to improve data throughput and / or network performance.

[0244] When CA scenarios involve co-located cells, this can mean that a first cell (e.g., PCell) and (multiple) second cells (e.g., SCell) share the same physical location or location and / or experience (multiple) similar propagation conditions, and the first cell (e.g., PCell) and (multiple) second cells (e.g., SCell) can use the same timing advance (TA). Timing advance (TA) can refer to a technique, such as ensuring that signals from different devices arrive at the base station at the correct time, e.g., without overlap. The base station can tell each device (e.g., UE) to delay or advance its transmission time so that all signals arrive at the base station synchronously. This timing offset can be called timing advance (TA). However, in this case, a common timing advance group (TAG) can be assigned to the first cell (e.g., PCell) and (multiple) second cells (e.g., SCell). Therefore, a timing advance group (TAG) can be a set of cells where the same timing advance value can be used. The timing advance group of the first cell (e.g., PCell) can be called the primary timing advance group (PTAG), and the timing advance group of the second cells (e.g., SCell) can be called the secondary timing advance group (STAG). Because timing synchronization can be maintained across these cells, the second cell (e.g., SCell) does not need to perform a separate random access procedure, such as a RACH procedure. Synchronization information from the first cell (e.g., PCell) can be sufficient, for example, within the same tag to maintain uplink timing alignment, particularly across all component carriers.

[0245] However, in non-co-located CA scenarios, the first cell (e.g., PCell) and (multiple) second cells (e.g., SCell) may be located in different locations, which can lead to (multiple) different propagation delays. Therefore, separate timing advances (TAs) may be required for the first cell (e.g., PCell) and (multiple) second cells (e.g., SCell), particularly to ensure accurate uplink synchronization. In this case, both the first cell (e.g., PCell) and (multiple) second cells (e.g., SCell) may need to perform independent random access procedures, such as RACH procedures, specifically to obtain (multiple) appropriate timing adjustments. The first cell (e.g., PCell) can use its own random access procedure (e.g., RACH procedure), while each second cell (e.g., SCell) can perform a different random access procedure (e.g., RACH procedure), particularly to determine its specific timing advance.

[0246] According to non-restrictive 3GPP specifications / examples, the random access procedure for SCell (e.g., the RACH procedure) may differ slightly from the random access procedure for PCell, as described below: In carrier aggregation (CA), contention-free random access (CFRA) on the secondary cell (SCell) can be specifically used to establish or update timing advance for the secondary timing advance group (sTAG). The steps for this process are as follows: Step 0: This process can be initiated by the base station (e.g., gNodeB (gNB)) via a PDCCH command, which is sent on an active SCell belonging to sTAG. Step 1: The PDCCH command instructs the User Equipment (UE) to perform a random access procedure using a dedicated preamble. The UE sends the assigned preamble on the SCell to synchronize with the network. Step 2: The gNB sends a Random Access Response (RAR) on the primary cell (PCell), which includes a timing advance command to adjust the timing of the UE's transmission to sTAG.

[0247] This process ensures precise synchronization for SCells, particularly without contention, enabling efficient communication and / or optimal performance in multi-carrier scenarios. By leveraging CFRA on SCells, the network can maintain tight control over timing alignment, which is crucial for supporting high-speed data transmission and / or seamless connectivity in carrier aggregation deployments.

[0248] In a random access procedure (e.g., RACH procedure) for a carrier aggregation SCell, the device (e.g., UE) may first transmit an access signal (e.g., a preamble, particularly a RACH preamble) on the SCell. The base station (e.g., gNB) may respond with an access response (e.g., a random access response (RAR)), which may be transmitted on the PCell, for example. This access response or RAR may include a timing advance (TA) command, which can be used to adjust the UE's transmission timing for a secondary timing advance group (sTAG). The timing advance command may, for example, instruct the device (e.g., UE) how to adjust the transmission timing in subsequent transmissions. However, transmitting the access response or RAR on the PCell, for example, may increase overall latency, especially in the case of inter-site carrier aggregation, and / or may require coordination between the PCell and SCell, particularly to ensure that the PCell, for example, transmits the access response or RAR within a specified access response or RA response window after the SCell, for example, receives the access signal (e.g., a preamble or PRACH preamble). Following the initial random access or random access channel (RACH) procedure, for example, if a synchronization loss occurs on, say, an SCell, the device (e.g., UE) may need to perform the random access or RACH procedure again, for example, using the same steps as during the initial random access or RACH procedure. Therefore, both the initial and subsequent random access procedures or RACH procedures can increase latency, process complexity, and / or create interdependencies between the PCell and SCell.

[0249] For example, the topics described herein can improve access procedures, such as by affecting their overall latency, reducing complexity (particularly procedural complexity), and / or reducing or minimizing interdependencies, particularly between a first cell (e.g., PCell) and a second cell (e.g., SCell). The topics described herein can provide flexibility in access response monitoring, such as monitoring access responses, like random access responses (RAR), which may include secondary timing advance groups (sTAG). The apparatus (e.g., user equipment (UE)) can determine where to monitor access responses, particularly based on the availability and / or presence / absence of at least one indication, which may specify the downlink (DL) carrier used to receive the access response.

[0250] The subject matter described herein refers to “at least one indication.” At least one indication may “indicate a downlink carrier for receiving an access response.” At least one indication may be provided to a device (e.g., a UE), particularly by the network. This may also be referred to as “configuring” the device (e.g., the UE). For example, at least one indication may be provided directly to the device, or may be included or embedded in a message, which may be referred to as a configuration message. Based on or depending on when at least one indication is provided, such as with regard to time, it may be referred to differently. For example, providing at least one indication may be used interchangeably herein with “pre-configuration” or “pre-configuring,” “a-prioriconfiguration” or “a-priori configuring,” and / or “pre-configured,” and / or it may refer to any form of configuration and / or signaling. This allows a device (e.g., a UE) to determine one or more operational parameters associated with the action, for example, before transmitting an access signal (e.g., a preamble). In the context of the access procedure, the prior configuration may involve or correspond to at least one indication that may specify a downlink (DL) carrier, for example, used to monitor access responses, such as random access responses (RAR), particularly in response to access signals, such as random access preambles. For example, at least one indication may be provided to the device (e.g., a UE): (i) Before, prior to, and / or preceding a command used to transmit access signals (e.g., a Physical Downlink Control Channel (PDCCH) command used to transmit a preamble), this may be referred to as “command pre-configuration.” To provide at least one indication, a dedicated message may be used, wherein the message may be at least one of the following: a Radio Resource Control (RRC) message, a System Information Block (SIB), or a Media Access Control (MAC) control element; (ii) It is embedded, included, and / or contained within a command used to transmit an access signal, such as within a PDCCH command used to transmit a preamble; this may be referred to as “configuration in command”. In particular, at least one indication may be directly and / or explicitly included within the command itself.

[0251] Therefore, prior configuration (especially providing at least one indication before the command to send the access signal, such as the PDCCH command to send the preamble) may include pre-configured associations i) advance reception, and / or ii) real-time instructions, for example, embedded in the command itself.

[0252] This process can introduce and / or provide flexibility, enabling tighter control over timing alignment and / or reducing overall latency, particularly for carrier aggregation (CA) procedures, for example by avoiding sending access responses (e.g., RARs) via the “intermediate cell” (e.g., via the PCell after the SCell first forwards it to the PCell), which may be referred to as message 2 or “Msg2” in the accompanying drawings. The topics described herein can be applied to situations where the first cell (e.g., PCell) and the second cell (e.g., SCell) require separate TAGs, i.e., for non-co-located CA cases.

[0253] For example, if the device (e.g., UE) monitors an access response, such as a random access response (RAR) message (e.g., Msg2), in response to an access signal (e.g., a preamble, particularly a RACH preamble, which may be referred to as “Msg1”) transmitted via an uplink of at least one second cell (e.g., SCell), then the device (e.g., UE) can monitor the access response in the downlink of at least one first cell. According to the subject matter described herein, the device (e.g., UE) can receive at least one indication indicating that the access response (e.g., Msg2) is monitored on the DL carrier of the cell to which the access signal (e.g., the preamble (e.g., Msg1)) is transmitted, thereby eliminating the need for additional SCell-PCell communication within a specified time window.

[0254] The device (e.g., UE) may be configured with at least two uplink channels, which may belong to at least two timing advances (TAs) or timing advance groups (TAGs). The at least two TAs or TAGs may be associated with at least one second cell (e.g., at least one secondary cell (SCell)) and one first cell (e.g., one primary cell (PCell)). The device (e.g., UE) may be configured to at least execute commands (e.g., Physical Downlink Control Channel (PDCCH) commands) for receiving access signals (e.g., Random Access Channel (RACH) preambles). For example, if a gNodeB wants to establish a timing advance for one of the timing advance groups, this command can be received from the base station (e.g., gNodeB (gnB)).

[0255] The device (e.g., UE) may or may not receive at least one indication (e.g., (pre)configuration) that may specify a downlink carrier of a first cell or at least one second cell of the network for receiving an access response. In one or more example embodiments described herein, at least one indication (e.g., pre) may be received before or during Physical Downlink Control Channel (PDCCH) signaling. The device (e.g., UE) may be made to act at least in part based on the availability of at least one indication (e.g., pre) because: i) if the device receives at least one indication (e.g., pre) and its indication receives an access response from a DL carrier of a first cell or at least one second cell, the device (e.g., UE) may monitor the access response on the DL carrier indicated in at least one indication; ii) if the device does not receive at least one indication (e.g., pre) the device (e.g., UE) may monitor the access response according to default monitoring behavior, such as monitoring the DL carrier of a first cell (e.g., PCell). Based on at least one indication, the device (e.g., UE) may receive an access response from at least one second cell (e.g., SCell) or from a first cell (e.g., PCell). Receiving an access response from SCell can be beneficial because it allows SCell-PCell coordination to be avoided, thereby reducing latency, for example.

[0256] Based on the topics described herein, a process for establishing a TAG within a Timing Advance Group (TAG) can be initiated. The process for establishing a TAG within a Timing Advance Group (TAG) may include receiving a command (e.g., a PDCCH command) to transmit access signals, such as preambles, like RACH preambles, from at least one second cell (e.g., SCell). The device (e.g., UE) may receive at least one indication (e.g., pre-configured) for monitoring access responses (e.g., RAR or Msg2) before or prior to receiving the command (e.g., the PDCCH command), such as via existing signaling, such as RRC, SIB, MAC, or any other signaling method, or via the command itself (e.g., the PDCCH command, etc.).

[0257] The device (e.g., UE) can also be made to transmit access signals or ranging messages (which may be used interchangeably herein) to a network (e.g., a base station, such as a gNB), such as preambles, random access preambles, or PRACH preambles. For example, the network can use the access signals to determine the reception timing and derive, in particular, the correct timing advance (TA). The device (e.g., UE) can be made to select an uplink carrier for transmitting the access signals. This selection may be at least partially based on or may correspond to implicit selection, for example, because an uplink carrier corresponding to the DL carrier through which the command is received is selected. Such implicit selection may be referred to, for example, a one-to-one association, linking, and / or mapping rule, particularly where each DL carrier may correspond to a (specific) uplink carrier. Alternatively, the device (e.g., UE) can be made to perform or make explicit selection, for example, at least partially based on or according to at least one explicit identifier of the uplink carrier, for example, included in the command.

[0258] The device (e.g., UE) can also be configured to monitor access responses, such as Random Access Response (RAR) messages, which may carry a Timing Advance Command (TAC) from the base station to the device (e.g., UE). The device (e.g., UE) may perform or monitor on the DL carrier of at least one second cell (e.g., SCell), particularly if at least one indication is received, and if no indication is received, it may perform or monitor on the DL of the first cell (e.g., PCell).

[0259] The device (e.g., UE) may also be configured to: receive an access response (e.g., a random access response (RAR) message) on at least one second cell (e.g., SCell) if the device receives an indication, or send an access response on a first cell (e.g., PCell) if at least one indication is not received.

[0260] The topics described herein can eliminate or at least reduce the separate need for PCell and SCell coordination, in particular ensuring that the PCell sends the RAR within a specified RA response window, such as after the SCell receives the PRACH preamble, and / or can avoid aggregation delays, such as exposure to (multiple) subsequent RACH procedures.

[0261] The device (e.g., the UE) can be configured to at least perform the transmission of an access signal, such as a preamble, like a RACH preamble. The device can be configured to transmit the access signal on a UL carrier associated with a command. This association can be implicit, for example, through an unambiguous association between carriers, such as if the device receives a command on a specific downlink (DL) carrier, it can be configured to transmit the access signal on the associated UL carrier; or it can be explicit, for example, the command itself can carry information about which uplink to transmit the access signal on.

[0262] In one example embodiment, based at least in part on the access signal, the network can determine the reception timing for the uplink and / or derive the correct timing advance. The network can send an access response, such as a Random Access Response (RAR) message. The access response may include a Timing Advance Command (TAC), such as a TAC associated with at least one second cell (e.g., SCell).

[0263] The apparatus (e.g., UE) can be made to perform monitoring of access responses, such as monitoring access responses carrying a TAC, such as access responses from base stations like gNBs. Monitoring can include monitoring access responses on the DL carrier of a first cell or on the DL carrier of at least one second cell. Monitoring on the DL carrier of the first cell or the DL carrier of at least one second cell can be based at least in part on the availability of at least one indication. To this end, for example before monitoring access responses, the apparatus (e.g., UE) can be made to: determine the availability and / or presence / absence of at least one indication, which indicates the downlink carrier of the first cell (e.g., gNB) of the network used to receive access responses or the downlink carrier of at least one second cell (e.g., gNB) of the network. Determining the availability (or unavailability) of at least one indication can include determining whether at least one indication i) exists, is included, is comprised, is found, is placed or embedded (e.g., in a message / command), or is provided (these terms are used interchangeably herein); or ii) does not exist, is missing, is unavailable, or, for example, the message / command does not have at least one indication or is defective (these terms are used interchangeably herein). The availability (or unavailability) of at least one indication can determine whether a first cell or at least one second cell will be selected and / or chosen for monitoring. Alternatively or additionally, the presence or absence of at least one indication can determine, specify, and / or specify which first cell or at least one first cell should be selected, used, and / or chosen for monitoring. In one example embodiment, the absence of at least one indication can cause default or conventional monitoring behavior. At least one indication can also indicate a deviation from default or conventional monitoring behavior. Default or conventional monitoring behavior can include monitoring access responses on the DL of a first cell (e.g., PCell) or the DL of at least one second cell (e.g., SCell), wherein the DL of the cell selected for the default monitoring behavior can be referred to as the "default DL," including the cell of the DL selected for the default monitoring behavior can be referred to as the "default" cell. Default or conventional monitoring behavior can be monitoring behavior specified in standard specifications, such as the 3rd Generation Partnership Project (3GPP), where the topics described herein have not yet been applied or are applicable.

[0264] In one example embodiment, the device (e.g., UE) can be configured such that if the device (e.g., UE) is a priori configured with a DL carrier for access response, such as a UL carrier that will transmit access signals via, the device (i.e., UE) can monitor the access response on that DL carrier; if the device (e.g., UE) is not a priori configured with a DL carrier for access response, the device (e.g., UE) can monitor the access response on a default DL carrier, such as a DL carrier predetermined by a standard specification (e.g., 3GPP specification), such as PCell.

[0265] The apparatus (e.g., the UE) can be configured to at least perform the determination of at least one indication present, exist, and / or be available, and can monitor response messages on a downlink carrier specified in at least one indication. At least one indication may include an explicit identifier of the downlink carrier to be used for monitoring access responses.

[0266] As described in this document, determining the availability of at least one indication can be part of the processing of a command for transmitting access signals, where the command can be a Physical Downlink Control Channel (PDCCH) command. This means that the availability determination step can be performed during the evaluation, analysis, and / or receipt of the command, such as checking whether the command includes at least one indication. Alternatively, determining the availability of at least one indication can be part of the processing of at least one configuration message. The configuration message can be received before the command is received (see Pre-command Configuration above). For example, the configuration message can be at least one of the following: at least one Radio Resource Control (RRC) message, at least one System Information Block (SIB), or at least one Media Access Control (MAC) Control Element (CE). This means that the availability determination step can be performed during the evaluation, analysis, and / or receipt of the configuration message, such as checking whether the configuration message includes at least one indication.

[0267] Based on the topics described herein, the device (e.g., UE) can be instructed to send access signals, such as random access preambles, and monitor corresponding random access response (e.g., RAR) messages. To ensure that the access response is received on the correct downlink carrier or from the appropriate cell, the network can provide the device (e.g., UE) with at least one indication specifying the downlink carrier to be used for monitoring the access response. The topics described herein can provide various ways or aspects through which at least one indication can be conveyed to the device (e.g., UE), each of which can provide specific advantages, such as in signaling efficiency, flexibility, and / or deployment scalability.

[0268] Based on the subject matter described herein, the apparatus (e.g., UE) can be made to determine that at least one indication exists or is available, which may cause the apparatus (e.g., UE) to monitor an access response on the downlink carrier of the cell specified in at least one indication, or to determine that at least one indication does not exist or is missing, which may cause the apparatus (e.g., UE) to monitor an access response at least partially based on or according to default monitoring behavior. In determining the presence of at least one indication, for example, at least one indication may be received before receiving a command to transmit an access signal (e.g., in an RRC message, SIB, or MAC-CE), or may be part of a command to transmit an access signal, such as a PDCCH command. In other words, the apparatus (e.g., UE) may determine whether to monitor the downlink carrier of a first cell (e.g., the primary cell (PCell)) or at least one second cell (e.g., SCell) to obtain an access response based on the presence or absence of an indication field. For example, (new) parameters (which may be referred to as...) RAResponseCell The field can be defined in 3GPP specifications (e.g., TS 38.331 (hereinafter)) and / or can be used to indicate that the device (e.g., UE) should monitor the access response on the downlink of the configured SCell. If the field is present, the device (e.g., UE) can monitor the access response on the DL carrier of at least one second cell (e.g., SCell). If the field is not present, the device (e.g., UE) can monitor the first cell (e.g., PCell). The topics described herein can provide low-overhead mechanisms, particularly for managing RAR monitoring behavior, and / or can provide the advantage of backward compatibility, particularly with legacy systems / equipment. The topics described herein can be particularly well-suited for straightforward network configurations, where implicit behavior (e.g., at least partially based on presence / absence) can be sufficient and / or desirable, for example, to reduce signaling complexity.

[0269] Based on the topics described herein, for example, if the device (e.g., UE) receives at least one indication specifying a downlink carrier of a first cell of the network used to receive an access response or a downlink carrier of at least one second cell of the network, the device (e.g., UE) may not need to perform a determination step. Based on the topics described herein, at least one indication can be included in a command (e.g., a PDCCH command) used to transmit access signals. At least one indication can be included as a field in a downlink control information (DCI) message or other control signaling structures transmitted via the physical downlink control channel (PDCCH). This enables real-time flexibility, such as allowing the network to dynamically select a target carrier for each access attempt. It can be particularly useful, for example, in multi-carrier deployments or load balancing scenarios, where it is beneficial to determine the RAR monitoring cell on a per-command basis. Because the command and at least one indication can be delivered together, this simplifies synchronization and / or minimizes latency.

[0270] Based on the topics described herein, at least one indication can be received prior to the command used to send the access signal, such as in a configuration message, like an RRC message, a System Information Block (SIB), or a MAC-CE. For example, the network can use, including... RAResponseCell The RRCReconfiguration message in the field configures at least one second cell, thereby instructing the device (e.g., UE) to monitor access responses on the downlink of at least one first cell (e.g., SCell). The device (e.g., UE) may subsequently receive commands for transmitting access signals (e.g., preambles, such as random access preambles or PRACH preambles). Based on the existing configuration, the device (e.g., UE) can monitor access responses on the DL carrier of the indicated cell. This can be advantageous because it provides a predictable and / or well-constructed approach to managing RAR reception, particularly in scenarios involving multiple timing advance groups (TAGs) or non-co-located cells. It allows the network to decouple configuration from execution, resulting in efficient signaling and / or robust interoperability, such as across devices or UEs and / or network implementations supporting advanced multi-cell setups.

[0271] The topics described herein (particularly the exemplary aspects and / or relevant embodiments) can be implemented independently or in combination, depending on system capabilities and / or deployment scenarios. The flexibility of these approaches enables optimized access procedures in systems supporting carrier aggregation (CA), dual connectivity (DC), and / or multi-TAG configurations, while maintaining compatibility with simpler network topologies.

[0272] Based on the subject matter described herein, where at least one indication is received before receiving a command to transmit an access signal (e.g., a PRACH preamble), at least one indication can be communicated during / within a Radio Resource Control (RRC) reconfiguration process, such as via an RRCReconfiguration message. During this process, the device (e.g., a UE) can be configured with one or more secondary cells, each potentially belonging to a specific timing advance group (TAG). Identified as tag-Id The field can be used to associate the configured cell with the TAG. Additionally, it can include fields defined as... RAResponseCell Parameters, for example, to indicate whether the device should monitor the corresponding access response (e.g., RAR message) on the downlink of the configured SCell. If RAResponseCell If the field exists, it indicates that the device (e.g., UE) can monitor RAR messages on the downlink of at least one second cell (e.g., SCell). If it does not exist, the device (e.g., UE) can be made to perform default monitoring or follow default monitoring behavior, such as monitoring access responses (e.g., RAR) on the downlink of at least one first cell (e.g., PCell). RAResponseCell The construction or presence of parameters allows the network to explicitly specify the downlink carrier associated with the access response (e.g., RAR), without implicit assumptions about default behavior. For example, while theoretically the presence or absence of a parameter / field can be interpreted using opposite polarities (e.g., presence = PCell, absence = SCell), such a configuration may not be robust in practice. This could be due to potential interoperability mismatches between network implementations that do not support the feature and those that are assumed to support it, potentially leading to incorrect RAR monitoring behavior. Therefore, presence-based coding can provide a more deterministic and / or backward-compatible signaling approach.

[0273] According to the subject matter described herein, at least one indication may be included, contained, or embedded in or as part of a command for transmitting an access signal. This may be referred to as an embodiment in which at least one indication may be directly embedded within a command that instructs the device (e.g., UE) to transmit an access signal. For example, the command may be a downlink control information (DCI) message delivered via the physical downlink control channel (PDCCH), such as a PDCCH command. The DCI may include an explicit reference to the cell or carrier in which the device (e.g., UE) should monitor RAR messages. This allows the network to dynamically instruct or guide the device (e.g., UE) on which cell's downlink to use for RAR reception in a context such as carrier aggregation (CA), dual connectivity (DC), or multiple TAG configurations. In an exemplary embodiment of the example aspect, where at least one indication is included in a command for transmitting an access signal, the device (e.g., UE) may receive at least one indication, for example, via the physical downlink control channel (PDCCH) in the form of downlink control information (DCI). The DCI may be encoded in various formats, depending on the type of scheduling information being conveyed. In some embodiments, the DCI can be in the form of DCI format 0_1, which can be used for uplink scheduling assignment. DCI format 0_1 ​​may include uplink grants, uplink grant identifiers allocated time-frequency resources for uplink transmissions, and parameters such as modulation and coding scheme (MCS), Hybrid Automatic Repeat Request (HARQ) procedure identifier, and New Data Indicator (NDI). In some implementations, DCI format 0_1 ​​may also include a timing advance command (TAC) to align uplink transmissions from the device with network timing. DCI format 0_1 ​​can be transmitted within a device-specific search space and can be directed to a specific device scheduled to transmit data on the uplink.

[0274] As described in this document, DCI can be in the form of DCI format 1_1, which can be used for downlink scheduling assignment. DCI format 1_1 can provide at least one indication of the Physical Downlink Shared Channel (PDSCH) resources allocated to the device (e.g., UE), and corresponding transmission parameters. These parameters may include the downlink MCS, HARQ procedure number, redundancy version (RV), and control information related to antenna port or precoding. DCI format 1_1 may also include at least one indication of time-domain resource allocation, and in some cases, may include a Transmission Configuration Indicator (TCI) status or a timeslot format indicator. Like DCI 0_1, DCI format 1_1 can be transmitted in a device-specific search space. Both DCI formats 0_1 and 1_1 can be designed for device-specific contexts and support cross-carrier scheduling, where control information received on one downlink carrier may correspond to data transmission or reception on another carrier. These formats can be used in conjunction with carrier aggregation (CA), dual connectivity (DC), or other multi-carrier radio access technologies.

[0275] For example, a command (e.g., DCI) may carry information in the form of a bit binary value (e.g., a one-bit binary value) to indicate the cell for which the device (e.g., UE) should monitor an access response. For example, "0" may represent a first cell, such as a primary cell (PCell), and "1" may represent at least one second cell, such as a secondary cell (SCell), and vice versa. Alternatively, the device (e.g., UE) may be configured to select the DL for the access response based at least in part on the presence or absence of the bit, particularly the presence or absence of the previously described bit. For example, if the bit is present, such as the previously described bit, the device (e.g., UE) may be made to monitor the access response on at least the DC of at least one second cell (e.g., SCell), while if the bit is absent, the device may be made to monitor the access response on the first cell (e.g., PCell). For both alternatives, the device (e.g., UE) may be pre-configured with the corresponding functionality to understand that the bit is present in the command. This configuration may be explicit or implicit (e.g., present in an indication, such as in the command, or in at least one indication received before the command is received). Explicit configuration can be beneficial because the device (e.g., the UE) may need to know the size of at least one indication, such as the size of a command or the size of an indication received before the command is received.

[0276] The configuration described above, based on the themes outlined herein, allows for flexible and / or reliable RAR monitoring behavior, particularly in scenarios involving non-co-located cells, multiple timing advance groups, and / or asymmetric uplink / downlink deployments. Specifically, the themes described herein eliminate the need for PCell and SCell coordination, particularly ensuring that SCells send access responses within a specified RA response window, such as after the SCell receives the access signal.

[0277] The expression “at least one indication specifying a downlink carrier” as used herein can be used interchangeably with at least one of the following expressions: “at least one indication identifying a downlink carrier”, “at least one indication associated with a downlink carrier”, “at least one indication referencing a downlink carrier”, “information indicating a downlink carrier”, and / or “instruction specifying a downlink carrier”. As described above, such an indication can be included in a configuration message, which may also be referred to as a “pre-command” message or embodiment, or included in a command used to transmit an access signal, which may also be referred to as a “in-command” embodiment. For the pre-command embodiment, at least one indication may be received before or prior to receiving the command used to transmit the access signal, for example, via existing signaling such as RRC, SIB, or MAC. For the in-command embodiment, at least one indication may be included in the command used to transmit the access signal, such as a PDCCH command, for example in DCI format (e.g., 0_1 or 1_1), particularly containing a downlink carrier index or binary field, or embedded in the command. RAResponseCell In the bit class.

[0278] The phrase “determine the availability of at least one indication” as used herein may be used interchangeably with at least one of the following phrases: “determine whether at least one indication is available”, “evaluate the availability of at least one indication”, or “determine whether at least one indication exists or does not exist”.

[0279] The expression “monitoring access responses on a downlink carrier of a first cell or at least a second cell, based at least in part on the availability of at least one indication” as used herein may be used interchangeably with at least one of the following expressions: “monitoring access responses based at least in part on whether at least one indication is available or present,” “monitoring a selected downlink carrier based at least in part on the availability of at least one indication,” “monitoring access responses based at least in part on the availability of an indication,” and / or “initiating monitoring based at least in part on the presence or absence of at least one indication.” In one example embodiment, “monitoring access responses on a downlink carrier of a first cell or at least a second cell, based at least in part on the availability of at least one indication” can be implemented by at least one or more of the following options: “monitoring on the downlink carrier associated with the transmitted access response if a configuration indicating such association is available,” “monitoring a predetermined default carrier in the absence of an indication,” “selecting among multiple downlink carriers based on a configuration indication and monitoring access responses on the selected carrier,” and “monitoring access responses on the default downlink carrier specified in the prior configuration or which is absent.” The statement “based at least in part on the availability of…” can be understood as allowing the following logic: “If at least one indication exists, use it / the information; if not, use the default rule, such as PCell.”

[0280] As used herein, the term "explicit identifier" can refer to a value, field, parameter, and / or signaling element or entity that is specifically and explicitly included in a message or configuration, and / or specifically and unambiguously designates a particular entity, such as a cell, carrier, channel, or resource. In the context of this disclosure, an explicit identifier for a downlink carrier can refer to a value provided to a device (e.g., a UE) that directly identifies a downlink carrier or cell to be used for a specific operation, such as monitoring an access response (e.g., a random access response message). An explicit identifier can be represented, for example, by at least one of the following: a dedicated field or parameter in a Radio Resource Control (RRC) message (e.g., RAResponseCell This includes fields, binary or multi-bit values ​​embedded in downlink control information (DCI) messages, carrier indexes or tag IDs included in configurations or commands, or any other explicitly signaled references that allow a device (e.g., a UE) to differentiate among multiple candidate downlink carriers. Explicit identifiers as used herein may differ from implicit indications or identifiers, where the selection or determination of a downlink carrier can be inferred or derived, for example, based at least in part on context, rules, and / or predefined associations (e.g., mapping downlink carriers at least in part based on the location of received commands or based on default behavior, etc.).

[0281] Based on the subject matter described herein, "receiving at least one indication of a downlink carrier for receiving an access response, wherein at least one indication is received prior to the receipt of a command for transmitting an access signal" means at least one of the following: "at least one prior indication identifying a downlink carrier for monitoring a response message", "at least one configuration received prior to the command for transmitting an access signal, including at least one indication of a downlink carrier", "control signaling received prior to access triggering, identifying a downlink carrier for access response monitoring", "at least one configuration message received prior to the command for transmitting an access signal, including at least one indication of a downlink carrier", and / or "at least one configuration message including one of the following: an RRC message, a System Information Block (SIB), or a MAC Control Element (CE)".

[0282] Based on the subject matter described herein, the term "configuration message" as used herein may refer to at least one of the following: "network-provided configuration", "control signaling for configuration device (e.g., UE)", "message including control information elements", "Radio Resource Control (RRC) message", "System Information Block (SIB)" or "SIB-based message / signal" or "MAC Control Element (MAC-CE)".

[0283] Based on the subject matter described herein, the term "command for sending access signals" as used herein may refer to at least one of the following: "access trigger message", "access initiation instruction", "downlink control message for access triggering", "downlink control information (DCI) message", "command sent via physical downlink control channel (PDCCH)" or "PDCCH command".

[0284] Based on the subject matter described herein, the term “access signal” as used herein may refer to at least one of the following: “access initiation message”, “ranging signal”, “uplink message for initiating access”, “message sent as part of a random access procedure”, “random access preamble”, “ranging message”, “message sent on the random access channel (RACH)”, “preamble sent on the PRACH” and / or “PRACH preamble”.

[0285] Based on the subject matter described herein, the term “access response” as used herein may refer to at least one of the following: “response message corresponding to access signal”, “network message including timing alignment information”, “message sent as part of a random access procedure” and / or “random access response (RAR) message”.

[0286] As stated above regarding the new parameters, the topics described herein may affect technical standard specifications, such as 3GPP standards, in ways that are merely examples. For instance, all features, elements, and / or steps described should be considered optional and, in particular, non-restrictive. For example, pre-configuration of a cell for monitoring access responses, such as random access response messages, may be provided along with secondary cell configurations. Specifically, if introduced into existing Radio Resource Control (RRC) specifications (e.g., TS 38.331), the additional information may be exemplarily summarized / reflected as follows (changes, additions, and / or revisions may be underlined): SCellConfig ::= SEQUENCE { sCellIndex SCellIndex, sCellConfigCommon ServingCellConfigCommon OPTIONAL, -- Cond SCellAdd sCellConfigDedicated ServingCellConfig OPTIONAL, -- Cond SCellAddMod ..., [[ Smtc SSB-MTC OPTIONAL -- Need S ]] } ServingCellConfig ::= SEQUENCE { tdd-UL-DL-ConfigurationDedicated TDD-UL-DL-ConfigDedicated OPTIONAL,-- Cond TDD [...] tag-Id TAG-Id, RAResponseCell ENUMERATED {SCell} OPTIONAL, -- SCellOnly [...]

[0287] The signaling structure will naturally differ for higher generations (e.g., sixth generation (6G)), but the basic logic remains the same—for example, when the device (e.g., UE) knows a cell and it belongs to the secondary timing advance group, pre-configuration for monitoring access response (e.g., RAR) can be provided.

[0288] The term “non-transient” as used in this article refers to a limitation on the medium itself (i.e., tangible, not signaling), rather than a limitation on the persistence of data storage (e.g., RAM vs. ROM).

[0289] As used herein, “at least one of the following: ” and “at least one of ” and similar wording (where a list of two or more elements is connected by “and” or “or”) means at least any one of these elements, or at least any two or more of these elements, or at least all of these elements.

[0290] The device may include a processor configured to provide signals to and receive signals from the device, and to control the functions of the device. The processor may be configured to control other elements of the device via electrical wires connecting the processor to other elements, such as a display or memory, to implement control signaling. For example, the processor may be embodied in various ways, including a circuit system, at least one processing core, one or more microprocessors with accompanying digital signal processors(s), one or more processors without accompanying digital signal processors, one or more coprocessors, one or more multi-core processors, one or more controllers, processing circuit systems, one or more computers, various other processing elements including integrated circuits (e.g., application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), etc.), or some combination thereof.

[0291] As used herein, the term "primary cell" (PCell) can refer to the cell associated with the device (e.g., user equipment (UE)) that serves as the cell for control signaling and / or initial connection establishment. The PCell can be the cell where the device (e.g., UE) is first configured during connection establishment and / or the cell that remains active throughout the RRC connected state, e.g., unless explicitly reconfigured. The PCell can operate on a designated primary frequency and can belong to the corresponding timing advance group (TAG). Unless a cell change, handover, or cell reconfiguration occurs, the device (e.g., UE) may specifically maintain continuous synchronization with the PCell.

[0292] As used herein, the term "secondary cell" (SCell) can refer to a cell that can be configured for an apparatus (e.g., a user equipment (UE)) in addition to the primary cell (PCell) in scenarios such as carrier aggregation (CA) or dual connectivity (DC). SCells can be used to improve throughput, extend coverage, and / or support different uplink / downlink frequency configurations. SCells can support additional data transmission channels, downlink and / or uplink scheduling and transmission, and / or (multiple) random access procedures, particularly in configurations where the SCell is associated with different timing advance groups (TAGs) from the PCell. SCells can be activated, modified, and / or deactivated at least in part based on network signaling (e.g., via RRC messages or MAC control elements), and / or may not carry primary control signaling unless specifically configured to do so.

[0293] As used herein, the term "Timing Advance Command" (TAC) can refer to a command sent from a base station (e.g., a gNB or eNodeB) to a device (e.g., a UE), for example, to instruct the device (e.g., the UE) to adjust the timing of its uplink transmissions. The purpose of a TAC can be to compensate for propagation delay between the device (e.g., the UE) and the base station, thereby ensuring time alignment of uplink signals at the base station receiver. A TAC can be included in a response message (e.g., a Random Access Response (RAR) message) or can be delivered via other control signaling mechanisms (such as MAC control elements). A TAC can contain a value representing the timing correction to be applied by the device (e.g., the UE), as an absolute offset or incremental value relative to the current timing. In systems supporting multiple Timing Advance Groups (TAGs), a TAC can be associated with a specific TAG, allowing different uplink carriers (e.g., in carrier aggregation or dual connectivity) to maintain independent timing alignment. The application of TAC by a device (e.g., UE) can enable accurate reception of uplink transmissions (such as PRACH preambles, PUSCH transmissions, or control signals) and / or support efficient resource utilization and interference management in time-division multiplexing systems.

[0294] As used herein, the term "timing advance" (TA) can refer to a time offset value applied by a device to its uplink transmission timing to compensate for signal propagation delay between the device (e.g., UE) and the base station (e.g., gNB or eNodeB). TA ensures that uplink transmissions from different devices arrive at the base station at the same time, thereby avoiding inter-symbol or inter-carrier interference in systems employing orthogonal multiple access schemes. The TA value can be determined by the base station based on the reception timing of the access signal, such as ranging or random access messages (e.g., PRACH preambles) transmitted by the device (e.g., UE). The base station can provide the device (e.g., UE) with a timing advance command (TAC) indicating the required timing correction. The TA value can be expressed in units of time or as a quantized offset. The application of TA is particularly beneficial in time-synchronized radio access technologies such as 5G or New Radio (NR) and / or can vary over time due to UE mobility or environmental changes.

[0295] As used herein, the term "Timing Advance Group" (TAG) can refer to a group of one or more uplink carriers or cells that share a common timing advance (TA) value, particularly a logical group. In carrier aggregation (CA) or dual connectivity (DC) scenarios, where user equipment (UE) can be configured with multiple uplink carriers, different TAGs can be defined to allow independent timing control for each group. Each TAG can be identified by a TAG ID and can be associated with one or more component carriers (CCs) or cells that are expected to have similar propagation delays relative to the base station. A separate timing advance command (TAC) can be issued for each TAG, enabling precise timing alignment for each group. For example, a primary cell (PCell) and a co-located secondary cell (SCell) can belong to the same TAG, while geographically separated SCells can belong to different TAGs. TAGs can enable efficient uplink synchronization across complex multi-carrier deployments and can be particularly important in scenarios involving non-co-located cells, multi-band operation, or asymmetric uplink / downlink topologies.

[0296] As used herein, the term "sTAG" may refer to a secondary timing advance group, such as a group of one or more secondary cells (SCells) that share a timing advance (TA) value different from that of the primary timing advance group (pTAG). Each TAG may allow a device (e.g., a UE) to independently align its uplink transmissions to different cell sets that may have different propagation delays, for example due to non-co-located deployments or frequency separation.

[0297] The term "circuit system" can refer to one or more, or all of the following: (a) Hardware circuit implementation only (e.g., implementation only in analog and / or digital circuit systems) and (b) A combination of hardware circuitry and software, such as (if applicable): (i) A combination of (multiple) analog and / or digital hardware circuits and software / firmware, and (ii) Any part of a hardware processor (including digital signal processors), software, and memory (including multiple memory) that works together to enable a device such as a mobile phone or server to perform various functions, and The hardware circuits and / or processors, such as microprocessors or a portion thereof, that require software (e.g., firmware) to operate, but may be absent when the software is not required to operate.

[0298] This definition of circuit system applies to all uses of the term in this application, including in any claim. As another example, as used herein, the term circuit system also covers implementations of only hardware circuitry or a processor (or processors) or a portion thereof, and its accompanying software and / or firmware. For example, if applicable to a particular claim element, the term circuit system also covers baseband integrated circuits or processor integrated circuits for mobile devices, or similar integrated circuits in servers, cellular network devices, or other computing or network devices.

[0299] The device may include memory capable of storing information elements. The device may include volatile memory and / or non-volatile memory. For example, volatile memory may include random access memory (RAM), including dynamic and / or static RAM, on-chip or off-chip cache memory, etc. Non-volatile memory (which may be embedded and / or removable) may include, for example, read-only memory, flash memory, magnetic storage devices such as hard disks, floppy disk drives, magnetic tape, optical disk drives and / or media, non-volatile random access memory (NVRAM), etc. Like volatile memory, non-volatile memory may include cache regions for temporary data storage. At least a portion of the volatile and / or non-volatile memory may be embedded in a processor. The memory may store one or more software programs, instructions, information, data, etc., which may be used by the device to perform the operations disclosed herein.

[0300] The device may be a user equipment (UE), such as a mobile or handheld device, such as a mobile phone or smartphone, or may be at least included in the UE.

[0301] Figure 1 A flowchart 100 illustrates an example aspect of the subject matter described herein. The flowchart may include steps of apparatus, methods, and / or non-transitory computer-readable media as described herein.

[0302] Flowchart 100 may include step 110 of determining the availability of at least one indication, which indicates a downlink carrier of a first cell of the network for receiving an access response or a downlink carrier of at least one second cell of the network. Flowchart 100 may include step 120 of monitoring an access response on a downlink carrier of the first cell or on a downlink carrier of at least one second cell, based at least in part on the availability of the at least one indication.

[0303] Flowchart 100 may include one or more additional steps, or in combination with, those associated with some of the example aspects and / or related example embodiments described herein.

[0304] Figure 2 A flowchart 200 illustrates an example aspect of the subject matter described herein. The flowchart may include steps of apparatus, methods, and / or non-transitory computer-readable media as described herein.

[0305] Flowchart 200 may include a step 210 of receiving at least one indication, which specifies a downlink carrier of a first cell of the network for receiving an access response or a downlink carrier of at least one second cell of the network, wherein the at least one indication is received prior to the receipt of a command for transmitting an access signal. Flowchart 200 may include a step 220 of monitoring the access response on the downlink carrier specified in the at least one indication.

[0306] Flowchart 200 may include one or more additional steps, or in combination with, those associated with or in combination with some of the example aspects and / or related example embodiments described herein.

[0307] Figure 3 A flowchart 300 illustrates an example aspect of the subject matter described herein. The flowchart may include steps of apparatus, methods, and / or non-transitory computer-readable media as described herein.

[0308] Flowchart 300 may include step 310 of receiving a command for transmitting an access signal, wherein the command includes at least one indication specifying a downlink carrier of a first cell of the network for receiving an access response or a downlink carrier of at least one second cell of the network. Flowchart 200 may include step 320 of monitoring the access response on the downlink carrier specified in the at least one indication.

[0309] Flowchart 300 may include one or more additional steps, or in combination with, those associated with or in combination with some of the example aspects and / or related example embodiments described herein.

[0310] Figure 4 An example flowchart based on the topics described in this article is shown. It should be noted that... Figure 4 The flowchart is merely an example, and the steps described and / or discussed should not be regarded as or interpreted as limitations. Figure 4 This can be used in conjunction with any example aspects and / or related example embodiments mentioned herein and / or Figures 1-3 Any combination of any of them. Figure 4 It can be described by the following non-restrictive steps: 400: The process of initiating a timed advance group for establishing a secondary cell during carrier aggregation. 410: The apparatus (e.g., UE) receives a command (e.g., PDCCH command) from the network (e.g., from gNB) to transmit an access signal (e.g., RACH preamble), wherein the command may include at least one indication, such as a priori configuration, which indicates a downlink carrier of at least one second cell (e.g., SCell) of the network for receiving an access response. 420: A device (e.g., a UE) transmits an access signal (e.g., a RACH preamble) via an uplink carrier of at least one second cell (e.g., a SCell), which may be referred to as “using SCell resources”. 430: The device (e.g., UE) determines the availability of at least one indication that indicates a downlink carrier of a first cell of the network for receiving an access response or a downlink carrier of at least one second cell of the network, which may be referred to as determining whether the device / UE has received prior configuration. 440: The device (e.g., UE) monitors an access response on a downlink carrier of a first cell or on a downlink carrier of at least one second cell, at least in part based on the availability of at least one indication, wherein if at least one indication is present, the device (e.g., UE) may monitor the response message on the downlink carrier specified in at least one indication, which may be referred to as “the device / UE monitors RAR messages on the DL carrier”, wherein if at least one indication is not present, the device (e.g., UE) may monitor the response message on the downlink of the primary cell, which may be referred to as “the device / UE monitors RAR messages on the DL of the PCell”. 450: If at least one indication exists, the network (e.g., gNB) may send an access response (e.g., RAR) on the DL specified in at least one indication, and if at least one indication does not exist, an access response (e.g., RAR) may be sent on the DL of PCell. 460: The device (e.g., UE) receives an access response (e.g., RAR).

[0311] Figure 4The flowchart may include or incorporate one or more additional steps associated with some of the example aspects and / or related example embodiments described herein.

[0312] Figure 5 Example signaling is shown for example aspects of the subject matter described herein. The example signaling may include the steps of the apparatus, methods, and / or non-transitory computer-readable media described herein.

[0313] Figure 5 The flowchart may include step 0, which involves receiving a command (e.g., a PDCCH command) from at least one second cell (e.g., from SCell) for transmitting an access signal (e.g., a RACH preamble), wherein the command includes at least one indication specifying a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response. Step 0 may also include determining the availability of at least one indication specifying the downlink carrier of the first cell of the network or the downlink carrier of at least one second cell of the network for receiving an access response, which may be referred to as “checking or evaluating a prior configuration”. Figure 5 The flowchart may include step 1, which involves sending an access signal (e.g., a RACH preamble) to at least one second cell (e.g., SCell). Figure 5 The flowchart may include step 2, which involves monitoring access responses on a downlink carrier of a first cell or at least a second cell, based at least in part on at least one indicated availability. Figure 5 In the example signaling, the command may include at least one indication specifying the DL carrier of the SCell for receiving the access response. Therefore, step 2 may include monitoring the access response on the DC of the SCell and receiving the access response, such as a RAR including an sTAG, via the aforementioned DC. Figure 5 In the example signaling, PCell and SCell coordination used to send access responses can be eliminated or at least reduced, which can reduce overall latency.

[0314] Figure 5 Example signaling may include or combine one or more additional steps associated with some of the example aspects and / or related example embodiments described herein.

[0315] Figure 6 Example signaling is shown for example aspects of the subject matter described herein. The example signaling may include the steps of the apparatus, methods, and / or non-transitory computer-readable media described herein.

[0316] Figure 6The flowchart may include step 0, which involves receiving a command (e.g., a PDCCH command) from at least one second cell (e.g., from SCell) for transmitting an access signal (e.g., a RACH preamble), wherein the command does not include, is missing, or lacks at least one indication specifying a downlink carrier of the first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response. Step 0 may also include determining the availability of at least one indication specifying a downlink carrier of the first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response, which may be referred to as “checking or evaluating a prior configuration”. Figure 6 The flowchart may include step 1, which involves sending an access signal (e.g., a RACH preamble) to at least one second cell (e.g., to a SCell). Figure 6 The flowchart may include step 2, which involves monitoring access responses on a downlink carrier of a first cell or on a downlink carrier of at least one second cell, based at least in part on at least one indicated availability. Figure 6 In the example signaling, the command may not include at least one indication specifying the DL carrier of the SCell for receiving the access response. Therefore, step 2 may include monitoring the access response on the DC of the PCell and receiving the access response via the aforementioned DC. Figure 6 In the example signaling, coordination between the PCell and SCell for sending the access response can be performed, as the SCell sends the access response, for example, a RAR including sTAG, to the PCell via the Xn interface, and then the PCell sends the access response to the device (e.g., the UE). Therefore, backward compatibility with legacy systems that do not provide or support at least one indication and / or previous configuration can be provided.

[0317] Figure 6 Example signaling may include or combine one or more additional steps associated with some of the example aspects and / or related example embodiments described herein.

[0318] While the foregoing describes embodiments of this disclosure, other and additional embodiments of this disclosure may be devised without departing from the basic scope of this disclosure, the scope of which is defined by the following claims. List of abbreviations CA carrier aggregation CC component carrier CE control elements PCell main cell SCell Auxiliary Community DC Dual Connection DCI Downlink Control Information DL downlink FPGA (Field Programmable Gate Array) gNB Next Generation Node B HARQ Hybrid Automatic Repeat Request MAC Media Access Control MCS modulation and coding scheme NDI New Data Indicator NVRAM Non-volatile Random Access Memory PDCCH (Physical Downlink Control Channel) PDSCH (Physical Downlink Shared Channel) RAR Random Access Response RACH Random Access Channel RRC (Radio Resource Control) RAM (Random Access Memory) SIB System Information Block TA scheduled in advance TAC timed advance command TAG Timed Advance Group sTAG auxiliary timing advance group pTAG Master Timing Advance Group TIC Transport Configuration Indicator UL uplink UE User Equipment List of reference numerals 100-300 Flowchart 110 Determine the steps Monitoring steps for 120, 220, and 320 210, 310 Receiving Steps

Claims

1. A device for communication, comprising: At least one processor; as well as At least one memory storing instructions that, when executed by the at least one processor, cause the device to perform at least the following: Receive at least one indication, the at least one indication indicating: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response, wherein the at least one indication is received prior to the receipt of a command for transmitting an access signal; The access response is monitored on the downlink carrier specified in at least one of the indications.

2. The apparatus of claim 1, wherein the at least one indication is included in a configuration message received from the network.

3. The apparatus of claim 2, wherein the at least one indication is included in at least one of the following: - Radio Resource Control (RRC) message, - System Information Block (SIB), or - Media Access Control (MAC) element.

4. The apparatus according to any one of the preceding claims, wherein the at least one indication is received via the downlink carrier specified in the at least one indication.

5. The apparatus according to any one of the preceding claims, wherein the at least one instruction is received from the at least one second cell.

6. The apparatus according to any one of the preceding claims, wherein the at least one indication indicates that the downlink carrier of the at least one second cell is used to receive the response message.

7. The apparatus according to any one of the preceding claims, wherein the at least one indication comprises: An explicit identifier for the downlink carrier used to receive the response message.

8. The apparatus according to any one of the preceding claims, wherein the apparatus is further caused to perform at least: The command is monitored, at least in part, on the downlink carrier of the first cell or on the downlink carrier of the at least one second cell, based on the at least one indication.

9. The apparatus according to any one of the preceding claims, wherein the apparatus is further caused to perform at least: The command for transmitting the access signal is received from the first cell or from the at least one second cell.

10. The apparatus according to any one of the preceding claims, wherein the at least one instruction and the command are received from the same cell in the first cell or the at least one second cell.

11. The apparatus according to any one of the preceding claims, wherein the command is a Physical Downlink Control Channel (PDCCH) command.

12. The apparatus according to any one of the preceding claims, wherein the apparatus is further caused to perform at least: The access signal is sent to the first cell or to the at least one second cell.

13. The apparatus of claim 12, wherein transmitting the access signal comprises: The access signal is transmitted to the first cell or the at least second cell to which the device receives the at least one indication.

14. The apparatus according to any one of the preceding claims, wherein the access signal is a Physical Random Access Channel (PRACH) preamble.

15. The apparatus according to any one of claims, wherein the apparatus is further configured to perform at least: The access response is received via the downlink carrier specified in the at least one indication.

16. The apparatus according to any one of the preceding claims, wherein the access response is a Random Access Response (RAR) message.

17. The apparatus according to any one of the preceding claims, wherein the presence of the at least one indication determines or decides which of the first cell or the at least one second cell will be selected or chosen for monitoring.

18. The apparatus according to any one of the preceding claims, wherein the access response includes a timing advance command (TAC) associated with the at least one second cell.

19. The apparatus according to any one of the preceding claims, wherein the at least one second cell and the first cell are associated with different timing advance TAs or different timing advance groups TAs.

20. The apparatus according to any one of the preceding claims, wherein the apparatus is configured with at least one uplink carrier to the at least one second cell and at least one uplink carrier to the first cell.

21. The apparatus according to any one of the preceding claims, wherein the at least one second cell is a secondary cell SCell of the network.

22. The apparatus according to any one of the preceding claims, wherein the first cell is the primary cell PCell of the network.

23. The apparatus according to any one of the preceding claims, wherein the apparatus is a user equipment (UE), or the apparatus is included in a UE.

24. A method for communication, comprising: Receive at least one indication, the at least one indication indicating: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response, wherein the at least one indication is received prior to the receipt of a command for transmitting an access signal; The access response is monitored on the downlink carrier specified in at least one of the indications.

25. A computer-readable storage medium comprising program instructions that, when executed by a device, cause operations including: Receive at least one indication, the at least one indication indicating: a downlink carrier of a first cell of the network or a downlink carrier of at least one second cell of the network for receiving an access response, wherein the at least one indication is received prior to the receipt of a command for transmitting an access signal; The access response is monitored on the downlink carrier specified in at least one of the indications.

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