Activation status of random access resources and associated adaptation

Abstract

Example embodiments of the present disclosure are directed to activation status of random access resources and associated adaptation. A method comprises receiving, from a first distributed unit (DU) of a first network device, an indication of a change of an activation status of a first type of random access resource, wherein the first type of random access resource is configured for a first cell, and the activation status indicates whether the first type of random access resource is activated or deactivated for the first cell; and transmitting, to a first centralized unit (CU) of the first network device, indication information indicating whether the first type of random access resource is applied by the first apparatus for a random access attempt to the first cell.

Description

ACTIVATION STATUS OF RANDOM ACCESS RESOURCES AND ASSOCIATED ADAPTATIONFIELD

[0001] Various example embodiments of the present disclosure generally relate to the field of telecommunication and in particular, to activation status of random access resources and associated adaptation.BACKGROUND

[0002] The random access procedure is a procedure to facilitate access of User Equipment (UE) to the network. UE may use random access resources, such as Physical Random Access Channel (PRACH) resources, in a random access attempt to a network device. The random access resources may be configured per cell.SUMMARY

[0003] In a first aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to: receive, from a first distributed unit (DU) of a first network device, an indication of a change of an activation status of a first type of random access resource, wherein the first type of random access resource is configured for a first cell, and the activation status indicates whether the first type of random access resource is activated or deactivated for the first cell; and transmit, to a first centralized unit (CU) of the first network device, indication information indicating whether the first type of random access resource is applied by the first apparatus for a random access attempt to the first cell.

[0004] In a second aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to: receive, from a terminal device, indication information indicating whether a first type of random access resource is applied by the terminal device for a random access attempt to a first cell, wherein the first type of random access resource is configured for a first cell under a first distributed unit (DU) of a first network device, and the first typeof random access resource is configured to be activated or deactivated over time by the first DU; and transmit at least the indication information to the first DU.

[0005] In a third aspect of the present disclosure, there is provided a third apparatus. The third apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to: transmit, to a first centralized unit (CU) of a first network device, first configuration information indicating a first type of random access resource configured for a first cell under a first distributed unit (DU) of the first network device; and transmit, to the first CU, first status information for the first cell, the first status information indicating an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

[0006] In a fourth aspect of the present disclosure, there is provided a fourth apparatus. The fourth apparatus comprises at least one processor; and at least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to: receive, from a first centralized unit (CU) of a first network device, first configuration information and first status information, wherein the first configuration information indicating a random access resource of the first type configured for a first cell in a first distributed unit (DU) of the first network device, and the first status information indicates an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

[0007] In a fifth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a first distributed unit (DU) of a first network device, an indication of a change of an activation status of a first type of random access resource, wherein the first type of random access resource is configured for a first cell, and the activation status indicates whether the first type of random access resource is activated or deactivated for the first cell; and transmitting, to a first centralized unit (CU) of the first network device, indication information indicating whether the first type of random access resource is applied by the first apparatus for a random access attempt to the first cell.

[0008] In a sixth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a terminal device, indication information indicatingwhether a first type of random access resource is applied by the terminal device for a random access attempt to a first cell, wherein the first type of random access resource is configured for a first cell under a first distributed unit (DU) of a first network device, and the first type of random access resource is configured to be activated or deactivated over time by the first DU; and transmitting at least the indication information to the first DU.

[0009] In a seventh aspect of the present disclosure, there is provided a method. The method comprises: transmitting, to a first centralized unit (CU) of a first network device, first configuration information indicating a first type of random access resource configured for a first cell under a first distributed unit (DU) of the first network device; and transmitting, to the first CU, first status information for the first cell, the first status information indicating an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

[0010] In an eighth aspect of the present disclosure, there is provided a method. The method comprises: receiving, from a first centralized unit (CU) of a first network device, first configuration information and first status information, wherein the first configuration information indicating a random access resource of the first type configured for a first cell in a first distributed unit (DU) of the first network device, and the first status information indicates an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

[0011] In a ninth aspect of the present disclosure, there is provided a first apparatus. The first apparatus comprises means for receiving, from a first distributed unit (DU) of a first network device, an indication of a change of an activation status of a first type of random access resource, wherein the first type of random access resource is configured for a first cell, and the activation status indicates whether the first type of random access resource is activated or deactivated for the first cell; and means for transmitting, to a first centralized unit (CU) of the first network device, indication information indicating whether the first type of random access resource is applied by the first apparatus for a random access attempt to the first cell.

[0012] In a tenth aspect of the present disclosure, there is provided a second apparatus. The second apparatus comprises means for receiving, from a terminal device, indicationinformation indicating whether a first type of random access resource is applied by the terminal device for a random access attempt to a first cell, wherein the first type of random access resource is configured for a first cell under a first distributed unit (DU) of a first network device, and the first type of random access resource is configured to be activated or deactivated over time by the first DU; and means for transmitting at least the indication information to the first DU.

[0013] In an eleventh aspect of the present disclosure, there is provided a third apparatus. The third apparatus comprises means for transmitting, to a first centralized unit (CU) of a first network device, first configuration information indicating a first type of random access resource configured for a first cell under a first distributed unit (DU) of the first network device; and means for transmitting, to the first CU, first status information for the first cell, the first status information indicating an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

[0014] In a twelfth aspect of the present disclosure, there is provided a fourth apparatus. The fourth apparatus comprises means for receiving, from a first centralized unit (CU) of a first network device, first configuration information and first status information, wherein the first configuration information indicating a random access resource of the first type configured for a first cell in a first distributed unit (DU) of the first network device, and the first status information indicates an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

[0015] In a thirteenth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the fifth aspect.

[0016] In a fourteenth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the sixth aspect.

[0017] In a fifteenth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the seventh aspect.

[0018] In a sixteenth aspect of the present disclosure, there is provided a computer readable medium. The computer readable medium comprises instructions stored thereon for causing an apparatus to perform at least the method according to the eighth aspect.

[0019] It is to be understood that the Summary section is not intended to identify key or essential features of embodiments of the present disclosure, nor is it intended to be used to limit the scope of the present disclosure. Other features of the present disclosure will become easily comprehensible through the following description.BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1 illustrates an example communication environment in which example embodiments of the present disclosure can be implemented;

[0021] FIG. 2 illustrates a signaling flow of current handing of RA report and PRACH configuration according to a current solution;

[0022] FIG. 3 illustrates a flow chart of a signaling flow according to some example embodiments of the present disclosure;

[0023] FIG. 4 illustrates a flow chart of an example signaling flow according to some example embodiments of the present disclosure;

[0024] FIG. 5 illustrates a flowchart of a process of random access reporting implemented at a terminal device according to some example embodiments of the present disclosure;

[0025] FIG. 6 illustrates a flowchart of a process of random access resource adaptation implemented at a network entity according to some example embodiments of the present disclosure;

[0026] FIG. 7 illustrates a flowchart of a method implemented at a first apparatus in accordance with some example embodiments of the present disclosure;

[0027] FIG. 8 illustrates a flowchart of a method implemented at a second apparatus in accordance with some example embodiments of the present disclosure;

[0028] FIG. 9 illustrates a flowchart of a method implemented at a third apparatus in accordance with some example embodiments of the present disclosure;

[0029] FIG. 10 illustrates a flowchart of a method implemented at a fourth apparatus inaccordance with some example embodiments of the present disclosure;

[0030] FIG. 11 illustrates a simplified block diagram of a device that is suitable for implementing example embodiments of the present disclosure; and

[0031] FIG. 12 illustrates a block diagram of an example computer readable medium in accordance with some example embodiments of the present disclosure.DETAILED DESCRIPTION

[0032] Principle of the present disclosure will now be described with reference to some example embodiments. It is to be understood that these embodiments are described only for the purpose of illustration and help those skilled in the art to understand and implement the present disclosure, without suggesting any limitation as to the scope of the disclosure. Embodiments described herein can be implemented in various manners other than the ones described below.

[0033] In the following description and claims, unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skills in the art to which this disclosure belongs.

[0034] References in the present disclosure to “one embodiment,” “an embodiment,” “an example embodiment,” and the like indicate that the embodiment described may include a particular feature, structure, or characteristic, but it is not necessary that every embodiment includes the particular feature, structure, or characteristic. Moreover, such phrases are not necessarily referring to the same embodiment. Further, when a particular feature, structure, or characteristic is described in connection with an embodiment, it is submitted that it is within the knowledge of one skilled in the art to affect such feature, structure, or characteristic in connection with other embodiments whether or not explicitly described.

[0035] It shall be understood that although the terms “first,” “second,”..., etc. in front of noun(s) and the like may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another and they do not limit the order of the noun(s). For example, a first element could be termed a second element, and similarly, a second element could be termed a first element, without departing from the scope of example embodiments. As used herein, the term “and / or” includes any and all combinations of one or more of the listed terms.

[0036] As used herein, “at least one of the following: ” and “at least one of ” and similar wording, where the list of two or more elements are joined by “and” or “or”, mean at least any one of the elements, or at least any two or more of the elements, or at least all the elements.

[0037] As used herein, unless stated explicitly, performing a step “in response to A” does not indicate that the step is performed immediately after “A” occurs and one or more intervening steps may be included.

[0038] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises”, “comprising”, “has”, “having”, “includes” and / or “including”, when used herein, specify the presence of stated features, elements, and / or components etc., but do not preclude the presence or addition of one or more other features, elements, components and / or combinations thereof.

[0039] As used in this application, the term “circuitry” may refer to one or more or all of the following:(a) hardware-only circuit implementations (such as implementations in only analog and / or digital circuitry) and(b) combinations of hardware circuits and software, such as (as applicable):(i) a combination of analog and / or digital hardware circuit(s) with software / firmware and(ii) any portions of hardware processor(s) with software (including digital signal processor(s)), software, and memory(ies) that work together to cause an apparatus, such as a mobile phone or server, to perform various functions) and(c) hardware circuit(s) and or processor(s), such as a microprocessor(s) or a portion of a microprocessor(s), that requires software (e.g., firmware) for operation, but the software may not be present when it is not needed for operation.

[0040] This definition of circuitry applies to all uses of this term in this application, including in any claims. As a further example, as used in this application, the term circuitry also covers an implementation of merely a hardware circuit or processor (or multiple processors) or portion of a hardware circuit or processor and its (or their) accompanying software and / or firmware. The term circuitry also covers, for example and if applicable to the particular claim element, a baseband integrated circuit or processor integrated circuit for a mobile device or a similar integrated circuit in server, a cellular network device, or other computing or network device.

[0041] As used herein, the term “communication network” refers to a network following any suitable communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), Narrow Band Internet of Things (NB-IoT) and so on. Furthermore, the communications between a terminal device and a network device in the communication network may be performed according to any suitable generation communication protocols, including, but not limited to, the first generation (1G), the second generation (2G), 2.5G, 2.75G, the third generation (3G), the fourth generation (4G), 4.5G, the fifth generation (5G), 5.5G, the sixth generation (6G) communication protocols, and / or any other protocols either currently known or to be developed in the future. Embodiments of the present disclosure may be applied in various communication systems. Given the rapid development in communications, there will of course also be future type communication technologies and systems with which the present disclosure may be embodied. It should not be seen as limiting the scope of the present disclosure to only the aforementioned system.

[0042] As used herein, the term “network device” refers to a node in a communication network via which a terminal device accesses the network and receives services therefrom. The network device may refer to a base station (BS) or an access point (AP), for example, a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), an NR NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, an Integrated Access and Backhaul (IAB) node, a low power node such as a femto, a pico, a non-terrestrial network (NTN) or non-ground network device such as a satellite network device, a low earth orbit (LEO) satellite and a geosynchronous earth orbit (GEO) satellite, an aircraft network device, and so forth, depending on the applied terminology and technology. In some example embodiments, radio access network (RAN)split architecture comprises a Centralized Unit (CU) and a Distributed Unit (DU) at an IAB donor node. An IAB node comprises a Mobile Terminal (IAB-MT) part that behaves like a UE toward the parent node, and a DU part of an IAB node behaves like a base station toward the next-hop IAB node.

[0043] The term “terminal device” refers to any end device that may be capable of wireless communication. By way of example rather than limitation, a terminal device may also be referred to as a communication device, user equipment (UE), a Subscriber Station (SS), a Portable Subscriber Station, a Mobile Station (MS), or an Access Terminal (AT). The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop -mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE), an Internet of Things (loT) device, a watch or other wearable, a head-mounted display (HMD), a vehicle, a drone, a medical device and applications (e.g., remote surgery), an industrial device and applications (e.g., a robot and / or other wireless devices operating in an industrial and / or an automated processing chain contexts), a consumer electronics device, a device operating on commercial and / or industrial wireless networks, and the like. The terminal device may also correspond to a Mobile Termination (MT) part of an IAB node (e.g., a relay node). In the following description, the terms “terminal device”, “communication device”, “terminal”, “user equipment” and “UE” may be used interchangeably.

[0044] As used herein, the term “resource,” “transmission resource,” “resource block,” “physical resource block” (PRB), “uplink resource,” or “downlink resource” may refer to any resource for performing a communication, for example, a communication between a terminal device and a network device, such as a resource in time domain, a resource in frequency domain, a resource in space domain, a resource in code domain, or any other combination of the time, frequency, space and / or code domain resource enabling a communication, and the like. In the following, unless explicitly stated, a resource in both frequency domain and time domain will be used as an example of a transmission resource for describing some example embodiments of the present disclosure. It is noted thatexample embodiments of the present disclosure are equally applicable to other resources in other domains.

[0045] FIG. 1 illustrates an example communication environment 100 in which example embodiments of the present disclosure can be implemented. As shown in FIG. 1, the communication environment 100 comprises one or more network devices, such as a network device 110-1, a network device 110-2, and one or more terminal devices such as a terminal device 120. For purpose of discussion, the network device 110-1 and network device 110-2 are collectively or individually referred to as network devices 110.

[0046] In some example embodiments, the network device 110-1 may be a RAN network device of a serving cell 140, for example, a gNB of the serving cell 140 for the terminal device 120. The network device 110-2 may be a RAN network device of a neighbor cell 150, for example, a gNB of the cell 150. The terminal device 120, for example, may be a UE served by the serving cell 140. The cell 150 may be a potential candidate to become a new serving cell for the terminal device 120.

[0047] In some example embodiments, a network device of a serving cell for a terminal device may support a split architecture, to include one or more distributed units (DUs), e.g., one or more gNB-DUs, and one or more centralized units (CUs), e.g., one or more gNB-CUs. For example, the network device 110 may include a CU 112-1, a DU 114-1 and a DU 114-2. The network device 110-2 may include a CU 112-2 and a DU 114-3. The DU 114-1, 114-2, 114-3 are collectively or individually referred to as DUs 114. In some example embodiments, a DU may be connected to the terminal device 120, and each DU may serve one or more cells.

[0048] A CU 112 may include a CU control plane (CU-CP), and a CU user plane (CU-UP). The CU-CP is responsible for handling control plane-related functions. The CU-UP is responsible for handling user plane-related functions. The CU-CP connects to the DU(s) via the Fl-C interface and is responsible for controlling and configuring the operations of the DU(s).

[0049] In the following, for the purpose of illustration, some example embodiments may be described with the network device 110-1 or the network device 110-2 operating as a network device. However, in some example embodiments, operations described in connection with a terminal device may be implemented at a network device or other device, and operations described in connection with a network device may be implemented at aterminal device or other device.

[0050] In some example embodiments, a communication direction from a network device 110 to the terminal device 120 is referred to as a downlink (DL), and a communication direction from the terminal device 120 to a network device 110 is referred to as an uplink (UL). In DL, the network device 110 is a transmitting (TX) device (or a transmitter) and the terminal device 120 is a receiving (RX) device (or a receiver). In UL, the terminal device 120 is a TX device (or a transmitter) and the network device 110 is a RX device (or a receiver).

[0051] Communications in the communication environment 100 may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) 802.11 and the like, and / or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Time Division Multiple Access (TDMA), Frequency Division Duplex (FDD), Time Division Duplex (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Division Multiple (OFDM), Discrete Fourier Transform spread OFDM (DFT-s-OFDM) and / or any other technologies currently known or to be developed in the future.

[0052] The random access (RA) attempts or RACH attempts of terminal devices to a cell are performed using random access resources configured for the cell. The random access resources may include PRACH resources. The terminal device may obtain a random access resource configuration for a cell, and the network entities may also share the random access resource configuration.

[0053] The random access resource configuration may need to be improved in some cases, which may be performed at the network side based on RA reports provided by the UE. The random access resource configuration per cell available in the RAN node (e.g., DU), and forwarded via the CU to neighbor cells within the same RAN node over F1 interface and / or within a neighboring RAN node over Xn interface. This forwarding may be triggered by the CU when required after reception of RA reports from the UE.

[0054] The RA report may be defined as follows:msgA-PUSCH-PayloadSize-r17 BIT STRING (SIZE (5)) OPTIONAL, onDemandSISucess-r17 ENUMERATED { true } OPTIONAL } },[ [usedFeatureCombination-r18 ReportedFeatureCombination-r18OPTIONAL,triggeredFeatureCombination-r18 ReportedFeatureCombination-r18OPTIONAL,startPreambleForThisPartition-r18 INTEGER (0..63) OPTIONAL, numberOfPreamblesPerSSB-ForThisPartition-r18 INTEGER (1..64)OPTIONAL,attemptedBWP-InfoList-r18 SEQUENCE (SIZE (1..maxNrofBWPs)) OF AttemptedBWP-Info-r18 OPTIONAL,numberOfLBT-Failures-r18 INTEGER (1..128) OPTIONAL, perRAInfoList-v1800 PerRAInfoList-v1800 OPTIONAL, intendedSIBs-r18 SEQUENCE (SIZE (1..maxSIB)) OF SIB-Type-r18 OPTIONAL] ]}AttemptedBWP-Info-r18 ::= SEQUENCE {locationAndBandwidth-r18 INTEGER (0..37949),subcarrierSpacing-r18 SubcarrierSpacing}ReportedFeatureCombination-r18 SEQUENCE {redCap-r18 ENUMERATED { true } OPTIONAL, smallData-r18 ENUMERATED { true } OPTIONAL, nsag-r18 NSAG-List-r17 OPTIONAL, msg3-Repetitions-r18 ENUMERATED { true } OPTIONAL, msg1-Repetitions-r18 ENUMERATED { true } OPTIONAL, eRedCap-r18 ENUMERATED { true } OPTIONAL, triggered-S-NSSAI-List-r18 SEQUENCE (SIZE (1..maxNrofS-NSSAI)) OF S-NSSAI OPTIONAL}PerRAInfoList-r16 ::= SEQUENCE (SIZE (1..200)) OF PerRAInfo-r16PerRAInfoList-v1660 ::= SEQUENCE (SIZE (1..200)) OF PerRACSI-RSInfo-v1660PerRAInfo-r16 ::= CHOICE {perRASSBInfoList-r16 PerRASSBInfo-r16,perRACSI-RSInfoList-r16 PerRACSI-RSInfo-r16}PerRAInfoList-v1800 ::= SEQUENCE (SIZE (1..200)) OF PerRAInfo-v1800PerRAInfo-v1800 ::= CHOICE {perRASSBInfoList-v1800 PerRASSBInfo-v1800,perRACSI-RSInfoList-v1800 PerRACSI-RSInfo-v1800PerRASSBInfo-v1800 ::= SEQUENCE {allPreamblesBlocked ENUMERATED { true } OPTIONAL, lbt-Detected-r18 ENUMERATED { true } OPTIONAL, }PerRACSI-RSInfo-r16 ::= SEQUENCE {csi-RS-Index-r16 CSI-RS-Index,numberOfPreamblesSentOnCSI-RS-r16 INTEGER (1..200)}PerRACSI-RSInfo-v1660 ::= SEQUENCE {csi-RS-Index-v1660 INTEGER (1..96) OPTIONAL }PerRACSI-RSInfo-v1800 ::= SEQUENCE {allPreamblesBlocked ENUMERATED { true } OPTIONAL, lbt-Detected-r18 ENUMERATED { true } OPTIONAL,

[0055] An information element (IE) may be defined to indicate the random access resource configuration, e.g., the PRACH resources used or reserved in the UL carrier(s) or SUL carrier(s) of the current cell. The random access resource configuration may include a PRACH configuration. An example of such IE may be defined as follow:

[0056] FIG. 2 illustrates a signaling flow 200 of current handing of RA report andPRACH configuration according to a current solution. In the signaling flow 200, a UE is served by a gNB (referred to as a serving gNB) which includes a DU represented as gNB-DU1 and a CU-CP represented as gNB-CU-CPl.

[0057] The gNB-DUl may transmit (201) a setup request to the gNB-CU-CPl via the Fl interface. For each cell served by the gNB-DUl, the setup request may include a PRACH configuration per cell. The gNB-CU-CPl may transmit (203) a setup request to the gNB-CU-CP2 in a neighboring gNB via the Xn interface between the two gNBs. This setup request may include the PRACH configuration per cell that is received from the gNB-DUl.

[0058] The gNB-CU-CP2 may also transmit (205) a setup response to the gNB-CU-CPl, which may include the PRACH configuration per cell that is received from the gNB-DU of the neighboring gNB. As such, the gNB-CU-CPl may thus obtain the PRACH configuration per cell of both gNB-DUl and gNB-CU-CP2. The gNB-CU-CPl may transmit (207), to the gNB-DUl, a gNB DU configuration update request to indicate the PRACH configuration per cell that is received from the gNB-CU-CP2.

[0059] When the UE goes to a connected mode (209) with the serving gNB, the UE may transmit (211) a UE information response including a PRACH report to the gNB-CU-CPl, via radio resource control (RRC) signaling. The gNB-CU-CPl may forward (213) the PRACH report to the gNB-DU 1 in an access mobility indication via the F1 interface. Then the gNB-DUl, the gNB-CU-CPl, and / or the gNB-CU-CP2 may perform (215) RACH optimization and conflict detection.

[0060] In legacy, the random access resources are always activated for a terminal device to be used. Currently, it is proposed to introduce different types of random access resources, which may include a type of random access resources that may be statically activated and a type of random access resources that may be activated or deactivated dynamically. The terminal devices are allowed to use the activated random access resources for a RA attempt to a cell. The other type of random access resources may be activated dynamically based on certain conditions, e.g., the cell load.

[0061] The type of random access resources (or PRACH resources) that are statically activated may sometimes be referred to as a second type of random access resources, or legacy or regular PRACH resources. The second type of random access resources may include a minimum set of PRACH resources, and may always be considered as activatedfor use by a terminal device. The type of random access resources (or PRACH resources) that are dynamically activated may sometimes be referred to as a first type of random access resources, or additional PRACH resources.

[0062] The introduction of the dynamically-activated random access resource may help network energy saving (NES) as the network may activate those resources only when needed, hence allowing for a minimum set of PRACH resources to be activated in low load periods. In some embodiments, NES-capable UEs may be allowed to use both the additional PRACH resources and the legacy PRACH resources. The additional PRACH resources may be configured and activated for NES-capable UEs only when needed, hence allowing the network device to enter longer sleeping periods in low load periods.

[0063] The configuration of the legacy PRACH resources may include, but is not limited to, random access preambles that are transmitted in time resources, a frequency domain resource for a PRACH preamble, a time domain resource for a PRACH preamble which may be defined based on a PRACH periodicity, a sub-frame number(s) containing PRACH slots (indicated by the Subframe number), the number of PRACH slots in a sub-frame (indicated by the Number of PRACH slots within a subframe), and the number of PRACH occasions in a PRACH slot.

[0064] The configuration of the additional PRACH resources may be based at least on a PRACH configuration index that may be the same and / or different from the PRACH configuration index for the legacy PRACH resources. It may include additional parameters for determining the additional PRACH resources, including a frequency domain parameter(s) (e.g., a frequency starting offset).

[0065] As mentioned above, it is expected to improve the configuration of the random access resources, including the different types of random access resources. However, based on the current RA Report provided by the UE to the network (as illustrated in FIG.2), the RA Report provided by the UE to the network does not indicate whether the reported RACH attempt was conducted on legacy or additional PRACH resources. As a result, the network may not be able to determine whether the reported RACH attempt was done on legacy or additional PRACH resources. The network will therefore not be able to determine which set of PRACH resources that would be concerned with any reported issue and could therefore not determine on which resources it should apply the corrective action.

[0066] Furthermore, due to dynamic activation and deactivation of the additionalPRACH resources, the network has less information available for corrective action than what is the case for legacy PRACH resources which are considered statically configured. Assuming that the UE performs a RA attempt on Cell 1, the following are the possible scenarios of inter-cell interference between Cell 1 and Cell 2 which could lead to RACH issues in Cell 1.

[0067] In a first scenario, a UE in Cell 2 uses the resources that correspond to additional PRACH resources in Cell 1 for PUSCH (or maybe other UL transmissions). If the UE in Cell 1 uses the additional PRACH resources in the RA attempt, then inter-cell interference may occur.

[0068] In a second scenario, Cell 1 and Cell 2 have configured the same resources as additional PRACH resources, and they are activated in Cell 2. Then the UE in Cell 1 may experience failed RA attempt due to the conflicting activated additional PRACH resources.

[0069] In a third scenario, Cell 2 uses the resources that correspond to additional PRACH resources in Cell 1 as regular PRACH resources. Resource collision may occur as the regular PRACH resources are always activated for use by UEs in Cell 2.

[0070] However the following case will not lead to RACH issues in Cell 1. That is, Celli and Cell2 have configured the same resources as additional PRACH resources, but these resources are deactivated in Cell 2.

[0071] It can be seen that absence of activation information of the dynamically-activated random access resources may thus create additional uncertainty in terms of choice of the corrective action, or whether a corrective action should be applied or not.

[0072] RACH performance has impacts on user experience and overall network performance. The RACH collision probability, and therefore access setup delays, data resuming delays from the UL unsynchronized state, handover delays, transition delays from RRC INACTIVE, and beam failure recovery delays are all affected by the RACH settings. In addition, performing RACH on the most suitable downlink beam may also be important and will avoid unnecessary power ramping and failed RA attempts. This is beneficial both for the network as well as for the attempting device; it allows to avoid unnecessary interference in the network and, also, reduce the experienced delay and UE energy consumption

[0073] According to example embodiments of the present disclosure, there are proposedsome solutions to facilitate adaptation of random access resources in time domain, which may provide enhanced flexibility of random access resource configuration. In some example embodiments, a terminal device indicates (e.g., within a RA Report) to a network entity whether the first type of random access resource (e.g., the random access resource that is dynamically activated) is used for a RA attempt. The network entity may be a CU of a network device to which the terminal device is connected.

[0074] In some example embodiments, status information of the first type of random access resource may be exchanged by a DU to a CU, or by a CU of a network device to a CU of another network device. The status information may indicate whether the first type of random access resource configured for a cell is activated or deactivated. The status information may be exchanged upon a change to an activation status of the first type of random access resource configured for the cell. With the stats information, the network device may be able to take a corrective action on the configuration of the first type of random access resources, the configuration of the second type of random access resources, and so on.

[0075] FIG. 3 illustrates a flow chart of a signaling flow 300 according to some example embodiments of the present disclosure. As illustrated in FIG. 3, the signaling flow 300 may involve the terminal device 120, the DU 114-1, the CU 112-1 and the CU 112-2. For the purposes of discussion, the signaling flow 300 will be discussed with reference to FIG.1.

[0076] In the following descriptions, while operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, while several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features that are described in the context of a single embodiment may also be implemented in multiple embodiments separately or in any suitable subcombination.

[0077] In the signaling flow 300, the DU 114-1 (as an example of a first DU of a first network device) transmits (317), to the terminal device 120, an indication of a change of an activation status of a first type of random access resource, and the terminal device 120 receives (319) the indication. The first type of random access resource is configured for the cell 140 (as an example of a first cell) under DU 114-1.

[0078] There may be multiple random access resources configured as the first type and configured for use in a cell. The first type of random access resources may be configured per cell, and thus may sometimes be referred to as per-cell first type of random access resources. The first type of random access resource may be dynamically activated or deactivated over time by the DU 114-1. The terminal device 120 may be allowed to use a random access resource of the second type for a RA attempt when the random access resource is configured as activated. In an example, the first type of random access resource may be referred to as the additional PRACH resource. Here, an activation status of the first type of random access resource may indicate whether the first type of random access resource is activated or deactivated for the cell 140.

[0079] In addition to the first type of random access resources, a cell may be configured with a second type of random access resources which may be statically configured as activated. That is, the terminal device 120 may always be able to select a random access resource of the second type for a RA attempt.

[0080] In some example embodiments, the indication received from the DU 114-1 may comprise a status switch indication of the first type of random access resource. The status switch indication may indicate the activation status of the first type of random access resource changes from being activated to being deactivated, or from being deactivated to being activated. In the example embodiments where the first type of random access resource is activated for the cell 140, the terminal device 120 may use the first type of random access resource for a RA attempt.

[0081] In some example embodiments, the CU 112-1 (as an example of a first CU of the first network device) may transmit, to the terminal device 120, configuration information associated with the cell 140. The terminal device 120 may receive the configuration information. The configuration information may indicate the first type of random access resource configured for the cell 140. For example, the additional PRACH resources may be configured to a UE by a gNB and may include parameters for determining theseadditional PRACH resources, for example, PRACH Configuration Index, msg1-FDM, msg1-FrequencyStart, time and frequency offsets when needed, etc..

[0082] Reference is still made to FIG. 3. The terminal device 120 transmits (321), to the CU 112-1 (as an example of a first CU of the first network device), indication information indicating whether the first type of random access resource is used by the terminal device 120 for a random access attempt to the cell 140. The CU 112-1 receives (323), from the terminal device 120, the indication information. In some example embodiments, the indication information may comprise: for a random access attempt to the cell 140, a first value to indicate that the first type of random access resource is used by the terminal device 120 for the random access attempt, or a second value to indicate that a second type of random access resource is used for the attempt. The second type of random access resource, legacy PRACH resource for example, may be configured to be statically activated. In an example, the indication information may indicate whether the additional PRACH resources or the legacy PRACH resource are used by using a Boolean.

[0083] In some example embodiments, the indication information may be transmitted in a RA report, such as a RACH report. The terminal device 120 may transmit, to the CU 112-1, the RA report comprising the indication information. The CU 112-1 may derive the indication information after receiving the RA report. Additionally, in some example embodiments, the RA report may be provided to the CU 112-1 in a UE Information response. In some example embodiments, the UE Information response may be transmitted over Radio Resource Control (RRC).

[0084] The following is an example of the RA report.

[0085] In the above, the IE “additionalPRACHResourcesUsed-R19” is added in the RA report to indicate whether the first type of random access resource (e.g., the additional PRACH resource) is used in a RA attempt. The IE may be set as a Boolean value, with one value to indicate that the first type of random access resource is used, and with another value to indicate that the first type of random access resource is not used.

[0086] Reference is still made to the signaling flow 300. The CU 112-1 transmits (325) at least the indication information to the DU 114-1. In some example embodiments, the CU 112-1 may transmit the indication information and configuration information of the first type of random access resource to the DU 114-1. The DU 114-1 receives (327) the indication information (and optional, the configuration information) of the first type of random access resource. In some example embodiments, the indication information may be used to indicate the CU 112-1 or the DU 114-1 whether to perform (329) a RACH optimization and a conflict detection.

[0087] In some example embodiments, if the first type of random access resource is used by the terminal device 120 for the RA attempt, the CU 112-1 and / or the DU 114-1 may detect whether there is a conflict in the first type of random access resources between the cell 140 and the cell 150. The CU 112-1 and / or the DU 114-1 may determine to analyze the RA report which indicates that the per-cell first type of random access resources is used in the corresponding RA attempt. In this case, the network entity may analyze the first type of random access resources reported in the RA report for a cell with the per-cell first type of random access resources configured for other cells.

[0088] The CU 112-1 and / or the DU 114-1 may identify any issues based on the analysis result and may determine a correction action to the first type of random access resources configured for any of the related cells. The potential issues may include a PRACH resource collision where the same random access resources of the first type are activated for two or more cells, or the activated random access resources of the first type are at least partially overlapped with the random access resources of the second type. The potential issues may alternatively or additionally include insufficient resource allocation for the first type or the second type, and the like.

[0089] In the above procedure, with the indication information of whether the first type of random access resource is used by the terminal device 120, the network entities such as the CU 112-1 and / or the DU 114-1 may detect whether there is a conflict in the firsttype of random access resources between the cell 140 and the cell 150. However, the indication information from the terminal device 120 may only indicate whether the first type of random access resources are being used in a RA attempt. The CU 112-1 may not be able to know the activation status or a change timeline of the activation status of the first type of random access resources. To improve the overall efficiency of the random access optimization and to reduce the number of measurements and RA reports for the network to detect patterns of activation status and arrive at the correct optimization decisions, in some example embodiments, it is proposed to share configuration information and status information about the first type of random access resources configured for a cell, and the sharing may be performed between the DU(s) and CU of the same network device, and the CUs of different network devices.

[0090] In some example embodiments, the CU 112-1 may be indicated that the first type of random access resource configured for the cell 140 based on information provided by the DU 114-1. The DU 114-1 may transmit (301), to the CU 112-1, first configuration information indicating the first type of random access resource configured for the cell 140. The CU 112-1 may receive (303) the first configuration information. In some example embodiments, the first configuration information may be provided in a setup request.

[0091] As shown below, Table 1 is an example of the configuration information for the first type of random access resource, which may configure the PRACH frequency start from a carrier, the PRACH frequency division multiplexing (FDM), and the PRACH configuration index.Table 1

[0092] In detail, the CU 112-1 may perform the conflict detection based on first status information and second status information. The first status information may indicate the activation status of the first type of random access resource for the cell 140. The second status information may indicate an activation status of a further random access resource of the first type within the cell 150. In some example embodiments, the CU 112-1 may further perform a corrective action for RACH optimization based on the detection of the conflict. Embodiments associated with the conflict detection and RACH optimization may be implemented at the DU 114-1, which will not be repeated here.

[0093] The first status information and the second status information mentioned above may be shared between different units by the following methods.

[0094] As shown below, Table 2 is an example of status information for the first type of random access resource.Table 2

[0095] In Table 2, the information element Additional PRACH Resources Activation Status indicates the activation status of the first type of random access resources (e.g., the additional PRACH resources) adapted for energy savings, e.g., to indicate whether it is activated or deactivated.

[0096] In some example embodiments, the DU 114-1 may transmit (305), to the CU 112-1, the first status information for the first cell. The CU 112-1 may receive (307) the first status information to get informed of the activation status of the first type of random access resource for the cell 140.

[0097] In some example embodiments, after receiving the first configuration information and the first status information, the CU 112-1 may share them with one or more CUs of one or more other network devices or share it with one or more other DUs of the network device 110-1. In one example, the CU 112-1 may transmit (309), to CU 112-2 (as an example of a second CU of the network device 110-2), the first configuration information and the first status information. The CU 112-2 may receive (313) the first configuration information and the first status information. The network device 110-2 may be a neighboring device of the network device 110-1. In other example, the CU 112-1 may transmit, to a second DU of the network device 110-1, the first configuration information.

[0098] In some example embodiments, the CU 112-2 may also share information with the CU 112-1. For example, the CU 112-2 may transmit (313), to the CU 112-1, second configuration information along with the second status information. The CU 112-1 may receive (315) the second configuration information and the second status information. The second configuration information may indicate the further random access resource of the first type configured for the cell 150 in the network device 110-2. In some example embodiments, the second configuration information and the second status information may be provided in a setup request. It is to be understood that, the second configuration information and the second status information may be provided by one or more CU of the network device 110-2. For example, the CU 112-2 of the network device 110-2 may receive, from the DU (not shown) of the network device 110-2, the second configuration information and the second status information as the DU may be serving the second cell.

[0099] After receiving the second configuration information and the second status information, the CU 112-1 may transmit them to the DU 114-1 or other DU(s) of the network device 110-1.

[0100] In some example embodiments, information of configuration (such as the first configuration information and the second configuration information) and information of status (such as the first status information and the second status information) may be not transmitted at the same time as the information of status may change more frequently.

[0101] In some example embodiments, when the activation status of the first type of random access resource for the cell 140 or the cell 150 changes, the first status information or the second status information may be updated accordingly. Take the first status information for example, the update to the first status information may comprise a status switch indication of the first type of random access resource from being activated to being deactivated, or from being deactivated to being activated. In the example embodiments where the status of the first type of random access resource is switched from being activated to being deactivated or from being deactivated to being activated for the cell 140, the DU 114-1 may transmit the updated first status information to the CU 112-1. In some example embodiments, the CU 112-1 may transmit the updated first status information to the CU 112-2 accordingly. In an example, the updated first status information may be transmitted in a configuration update message. Similarly, in the example embodiments where the status of the first type of random access resource is switched from being activated to being deactivated or from being deactivated to being activated for the cell 150, the CU 112-2 may transmit, to the CU 112-1, an update to the second status information. Embodiments associated with the first status information may be implemented for the second status information, which will not be repeated here.

[0102] In some example embodiments, information about timeline associated with the activation status of the first type of random access resource configured for a cell may be determined at the terminal device 120 and / or the CU 112-1.

[0103] In some example embodiments, the CU 112-1 may determine first timeline information for the first type of random access resource configured for a cell. In some example embodiments, the first timeline information may indicate at least one of the following: at least one time period when the first type of random access resource is to be activated, or at least one time period when the first type of random access resource is to be deactivated. The CU 112-1 may determine the first timeline information based on the first status information provided by the DU 114-1. The first timeline information may be determined based on the status information and any change to the status information received from the DU or a further CU (depending on which DU serves the correspondingcell). For example, the CU 112-1 may record the time duration from the timepoint when the first type of random access resource is indicated by the DU or the further CU to be activated to the timepoint when the first type of random access resource is indicated by the DU or the further CU to be deactivated, and so on.

[0104] In some example embodiments, the CU 112-1 may not send the timeline information to the DU 114-1. For example, if the DU 114-1 doesn’t send the first status information to the CU 112-1, then the CU 112-1 may not maintain and send the timeline information to the DU 114-1.

[0105] In some example embodiments, the terminal device 120 may determine second timeline information for the first type of random access resource configured for a cell. In some example embodiments, the second timeline information may indicate at least one of the following: at least one time period when the first type of random access resource is to be activated, or at least one time period when the first type of random access resource is to be deactivated. In some example embodiments, the terminal device 120 may transmit the second timeline information to the CU 112-1. The CU 112-1 may receive the second timeline information. In some example embodiments, the CU 112-1 may transmit timeline information (the first timeline information or the second timeline information) to the DU 114-1. In some example embodiments, the timeline information may be transmitted along with the indication information.

[0106] In some example embodiments, the terminal device 120 may maintain the timeline information for the first type of random access resource configured for a cell. For example, the terminal device 120 may record the time duration from the timepoint when the first type of random access resource is indicated by the DU 114-1 to be activated to the timepoint when the first type of random access resource is indicated by the DU 114-1 to be deactivated, and so on.

[0107] In summary, there may be 4 options of the transmission of the timeline information:1) CU 112-1 maintains the timeline informationOption 1: the DU 114-1 sends the first status information to the CU 112-1. In this case, the CU 112-1 creates the timeline information and shares it with the DU 114-1;Option 2: the DU 114-1 doesn’t send the first status information to the CU 112- 1. In this case, the CU 112-1 doesn’t send the timeline information to the DU 114-1.2) the terminal device 120 maintains the timeline informationOption 3: the DU 114-1 sends the first status information to the CU 112-1. In this case, the CU 112-1 may send its own timeline information and / or the timeline information received from the terminal device 120 to the DU 114-1; Option 4: the DU 114-1 doesn’t send the first status information to the CU 112- 1. In this case, the CU 112-1 may send timeline information the timeline information received from the terminal device 120 to the DU 114-1.

[0108] In conclusion, in example embodiments of the present disclosure, the PRACH configuration information exchanged between neighbor cells (over Fl and Xn interfaces) may be enhanced to include information about the first type of random access resources and (optionally) the activation status of the first type of random access resources. In some embodiments, the configuration of the first type of random access resources for a cell may be exchanged along with the activation status by a DU to a CU in the same network device, e.g., over the Fl interface. In some embodiments, the received configuration of the first type of random access resources along with the activation status may be shared by the CU of the network device over Fl to the other DU(s) in the same network device and / or over Xn interface to the neighboring network devices. The activation status may be signaled separately from the configuration of the first type of random access resources since their periodicities may be different (for example, the activation status may change more often).

[0109] Alternatively, or additionally, the terminal device may indicate, within its RA Report, whether the second type of random access resources or the first type of random access resources were used for the reported RA attempt. The additional information reported by the terminal device together with the enhanced information received from other cells may enable the network to determine whether corrective action, if any, needs to be taken on the second type of random access resources and / or on the first type of random access resources.

[0110] With the shared and received information, the network may make use of the received additional information to take corrective action on the first type and / or the secondtype of random access resources.

[0111] To better understand the solution of the present disclosure, some more detailed example embodiments are described below.

[0112] FIG. 4 illustrates an example signaling flow 400 according to some example embodiments. As illustrated in FIG. 4, the signaling flow 400 involves the terminal device 120, the DU 114-1, the CU 112-1 and the CU 112-2. The signaling flow 400 may be considered as an example of the signaling flow 300. In the signaling flow 400, for the purpose of discussion, the term of “additional PRACH resources” is used to refer to the first type of random access resource that may be dynamically activated or deactivated.

[0113] As shown in FIG. 4, at 401, the DU 114-1 may transmit, to the CU 112-1, additional PRACH configuration (as an example of the first configuration information) and Activation Status (as an example of the first status information) in a setup request over the Fl interface.

[0114] At 402, the CU 112-1 may transmit, to the CU 112-2, the additional PRACH configuration and the Activation Status (received from the DU 114-1) in a setup request over the Xn interface.

[0115] At 403, the CU 112-2 may transmit, to the CU 112-1, additional PRACH configuration (as an example of the second configuration information) and Activation Status (as an example of the second status information) in the setup request over the Xn interface.

[0116] At 404, the CU 112-1 may transmit, to the DU 114-1, the additional PRACH configuration and the Activation Status (received from the CU 112-2) in a gNB CU Config Update Request over the Fl interface.

[0117] At 405, the CU 112-1 may store the Activation Status and additional PRACH Config, which includes the additional PRACH configuration and Activation Status of both gNB-DUl (as an example of the DU 114-1) and gNB-CU-CP2 (as an example of the CU 112-2).

[0118] At 406, the activation status of the first type of random access resource for the cell 140 may change, which may be aware of by the DU 114-1.

[0119] At 407, in response to the activation status changes, the DU 114-1 may transmit,to the terminal device 120, the indication of the change of the first type of random access resource for the cell 140.

[0120] At 408, the DU 114-1 may transmit, to the CU 112-1, the Activation Status (the updated first status information) in DU Config Update Request (as an example of the configuration update message of DU 114-1) over the Fl interface.

[0121] At 409, the CU 112-1 may transmit, to the CU 112-2, the Activation Status (the updated first status information) in NG-RAN Config Update Request over Xn.

[0122] At 410, the CU 112-1 may store the Activation Status (the updated first status information).

[0123] At 411, the CU 112-1 may transmit, to the DU 114-1, the Activation Status (the updated first status information) in CU Config Update Request (as an example of the configuration update message of CU 112-1) over the Fl interface.

[0124] At 412, the activation status of the first type of random access resource for the cell 150 may change.

[0125] At 413, the CU 112-2 may transmit, to the CU 112-1, the Activation Status (the updated second status information) in NG-RAN Config Update Request over Xn.

[0126] At 414, the CU 112-1 may store the Activation Status (the updated second status information).

[0127] At 415, the CU 112-1 may transmit, to the DU 114-1, the Activation Status (the updated second status information) in CU Config Update request over the Fl interface.

[0128] At 416, the UE (as an example of the terminal device 120) may go to connected mode.

[0129] At 417, the terminal device may transmit the indication information indicating whether the additional PRACH resources are used in a RA attempt as indicated in the PRACH report received via the UE Information Response transmitted over RRC signaling.

[0130] At 418, the CU 112-1 may transmit the indication information, additional PRACH configuration and (optionally) Activation Status Timeline information for the additional PRACH resources configured for a cell to the DU 114-1.

[0131] At 419, the DU 114-1, the CU 112-1 and / or the CU 112-2 may perform RACHoptimization and conflict detection based on the information shared above.

[0132] In summary, from 401 to 405, the additional PRACH resources and their activation status are shared over Fl and Xn interfaces. The PRACH Resources are configurated and (de)activated in the gNB-DU and shared with the gNB-CU-CP. The gNB-CU-CP shares the same information with the neighboring gNB-CU as well with other gNB-DUs in the same gNB. The gNB-CU-CP stores the additional PRACH resources, the activation status and the overall timeline of events.

[0133] From 406 to 411, the additional PRACH resources activation status may change from being activated to deactivated or vice versa, and the changed activation status may be shared over Fl and Xn interfaces. The gNB-CU-CP stores the changed activation status and the overall timeline of events.

[0134] From 412 to 415, any activation status change in the neighboring gNBs may also be shared over Xn and Fl interfaces. The gNB-CU-CP stores the changed activation status and the overall timeline of events.

[0135] From 416 to 419, the UE, when it sends the RACH Report to the gNB, indicates if the PRACH related parameters were for the legacy RACH resources or the additional PRACH resources using a BOOLEAN. The gNB may correlate between the received and stored information for its logic of PRACH optimization.

[0136] In a simpler embodiment, the Additional PRACH configuration status may not be shared over Fl and Xn interface at all. In this way, the overall signaling and handling may be much simplified and there is a greater chance of RAN3 acceptance. However, not knowing the activation status may reduce the overall efficiency of the PRACH optimization and it may take more time / a greater number of measurements and UE RA Reports for the network to detect patterns of activation status and arrive at the correct optimization decisions.

[0137] FIG. 5 illustrates a flowchart of a process 500 of random access reporting implemented at the terminal device 120 according to some example embodiments of the present disclosure.

[0138] At block 510, the terminal device 120 may receive and store per-cell first type of random access resources. The per-cell first type of random access resources may be received from a network device (e.g., the CU 112-1) over RRC signaling. The per-cell firsttype of random access resources may be configured for use in a cell.

[0139] At block 520, the terminal device 120 may receive and store a per-cell activation status of the per-cell first type of random access resources. The per-cell activation status may be received from the network device (e.g., the DU 114-1) over downlink control information (DCI). The per-cell activation status may indicate whether the per-cell first type of random access resources are activated or deactivated.

[0140] At block 530, the terminal device 120 may receive and store any change in the activation status of the per-cell first type of random access resources. For example, the DU 114-1 may indicate, to the terminal device 120, a change in the activation status of the per-cell first type of random access resources.

[0141] In some examples, the terminal device 120 may store each of the changes in the activation status of the per-cell first type of random access resources. In some example examples, the terminal device 120 may create a timeline of the changes of the activation status of the per-cell first type of random access resources, to indicate when the per-cell first type of random access resources is activated, and when the per-cell first type of random access resources is then deactivated.

[0142] At block 540, the terminal device 120 may store in an IE (which may be referred to as Additional PRACH Resources Used) for each RA attempt within the RA report based on which type of resources the RA report is relevant for. For example, the IE may indicate whether the per-cell first type of random access resources is used in the corresponding RA attempt. The IE Additional PRACH Resources Used may be set to TRUE to indicate that the per-cell first type of random access resources is used in a RA attempt, or to FALSE to indicate that the per-cell first type of random access resources is not used in a RA attempt.

[0143] At block 550, the terminal device 120 may send the RA report to the network device, e.g., to the CU 112-1 of the network device.

[0144] FIG. 6 illustrates a flowchart of a process 600 of random access resource adaptation implemented at a network entity according to some example embodiments of the present disclosure. The network entity implementing the process 600 may be any one of the DU 114-1, CU 112-1, or CU 112-2 or any DU or CU involved in the sharing of activation status of the first type of random access resources and the random accessresource adaptation.

[0145] At block 610, the network entity may store the per-cell first type of random access resources. The per-cell first type of random access resources may be configured for a cell served by the network entity, e.g., a cell serving by the DU, or may be configured for a cell served by another entity, e.g., a cell serving by the neighboring RAN network device or serving by another DU under the same RAN network device. The network entity implementing the process 600 may receive the per-cell first type of random access resources from another network entity, or may configure the per-cell first type of random access resources for a cell served itself.

[0146] At block 620, the network entity may store a per-cell activation status of the per-cell first type of random access resources. For a CU, the per-cell first type of random access resources for a cell may be received from a DU or from another CU. For a DU, it may receive, from the CU, the per-cell first type of random access resources for other cell(s) that are not served by this DU. For a DU, it may be aware of the per-cell activation status of the per-cell first type of random access resources for the serving cell as the DU may dynamically activate or deactivate the first type of random access resources for its serving cell.

[0147] At block 630, the network entity may store any change in the activation status of the per-cell first type of random access resources. For a CU, the change in the activation status of the per-cell first type of random access resources for a cell may be received from a DU or from another CU. For a DU, it may receive, from the CU, the change in the activation status of the per-cell first type of random access resources for other cell(s) that are not served by this DU. For a DU, it may be aware of the change in the activation status of the per-cell first type of random access resources for the serving cell as the DU may dynamically activate or deactivate the first type of random access resources for its serving cell.

[0148] The random access optimization (or the corrective action) may then be performed based on whether the random access resource-related parameters were for the first type of random access resources or the second type of random access resources, based on the stored information (the configuration of the first type of random access resources, the activation status and the overall timeline of activation and deactivation events.

[0149] For example, at block 640, the network entity may receive and analyze the RAreport from the terminal device, and may compare it against the stored timeline, activation status, and / or configuration of the per-cell first type of random access resources. The timeline may indicate when the per-cell first type of random access resources is activated or deactivated for the corresponding cell.

[0150] The network entity may determine to analyze the RA report which indicates that the per-cell first type of random access resources is used in the corresponding RA attempt. In this case, the network entity may analyze the per-cell first type of random access resources reported in the RA report for a cell with the per-cell first type of random access resources configured for other cells.

[0151] At block 650, the network entity may identify any issues based on the analysis result and may determine a correction action to the first type of random access resources configured for any of the related cells. The potential issues may include a PRACH resource collision where the same random access resources of the first type are activated for two or more cells, or the activated random access resources of the first type are at least partially overlapped with the random access resources of the second type. The potential issues may alternatively or additionally include insufficient resource allocation for the first type or the second type, and the like.

[0152] FIG. 7 shows a flowchart of an example method 700 implemented at a first apparatus in accordance with some example embodiments of the present disclosure. The first apparatus may be or may be comprised in the terminal device 120 in FIG. 1. For the purpose of discussion, the method 700 will be described from the perspective of the first apparatus.

[0153] At block 710, the first apparatus receives, from a first distributed unit (DU) of a first network device, an indication of a change of an activation status of a first type of random access resource, wherein the first type of random access resource is configured for a first cell, and the activation status indicates whether the first type of random access resource is activated or deactivated for the first cell.

[0154] At block 720, the first apparatus transmits, to a first centralized unit (CU) of the first network device, indication information indicating whether the first type of random access resource is applied by the first apparatus for a random access attempt to the first cell.

[0155] In some example embodiments, the method 700 further comprises: receiving, from the first CU of the first network device, configuration information associated with the first cell, the configuration information indicating the first type of random access resource configured for the first cell.

[0156] In some example embodiments, the indication received from the first DU comprises a status switch indication of the first type of random access resource from being activated to being deactivated, or from being deactivated to being activated.

[0157] In some example embodiments, the method 700 further comprises: transmitting, to the first CU of the first network device, timeline information indicating at least one of the following: at least one time period when the first type of random access resource is activated, or at least one time period when the first type of random access resource are deactivated.

[0158] In some example embodiments, the indication information comprises: for a random access attempt to the first cell, a first value to indicate that the first type of random access resource is applied by the first apparatus for the random access attempt, or a second value to indicate that a second type of random access resource is applied by the first apparatus for the random access attempt, the second type of random access resource being configured to be statically activated.

[0159] In some example embodiments, the method 700 further comprises: transmitting, to the first CU of the first network device, a physical random access channel report comprising the indication information.

[0160] In some example embodiments, the first apparatus is or is comprised in a terminal device.

[0161] FIG. 8 shows a flowchart of an example method 800 implemented at a second apparatus in accordance with some example embodiments of the present disclosure. The second apparatus may be or may be comprised in a CU 112-1 of the network device 110 in FIG. 1. For the purpose of discussion, the method 800 will be described from the perspective of the second apparatus.

[0162] At block 810, the second apparatus receives, from a terminal device, indication information indicating whether a first type of random access resource is applied by the terminal device for a random access attempt to a first cell, wherein the first type of randomaccess resource is configured for a first cell under a first distributed unit (DU) of a first network device, and the first type of random access resource is configured to be activated or deactivated over time by the first DU.

[0163] At block 820, the second apparatus transmits at least the indication information to the first DU.

[0164] In some example embodiments, the method 800 further comprises: transmitting, to the terminal device, configuration information associated with the first cell, the configuration information indicating the first type of random access resource configured for the first cell.

[0165] In some example embodiments, the method 800 further comprises: determining timeline information for the first type of random access resource, the timeline information indicating at least one of the following: at least one time period when the first type of random access resource is to be activated, or at least one time period when the first type of random access resource is to be deactivated; and transmitting the timeline information and the indication information to the first DU.

[0166] In some example embodiments, the method 800 further comprises: receiving, from the terminal device, further timeline information indicating at least one of the following: at least one time period when the first type of random access resource is activated, or at least one time period when the first type of random access resource is deactivated.

[0167] In some example embodiments, the indication information comprises: for a random access attempt to the first cell, a first value to indicate that the first type of random access resource is applied by the first apparatus for the random access attempt, or a second value to indicate that a second type of random access resource is applied by the first apparatus for the random access attempt, the second type of random access resource being configured to be statically activated.

[0168] In some example embodiments, the method 800 further comprises: receiving, from the terminal device, a physical random access channel report comprising the indication information.

[0169] In some example embodiments, the method 800 further comprises: receiving, from the first DU, first status information for the first cell indicating an activation statusof the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

[0170] In some example embodiments, the method 800 further comprises: transmitting, to a second centralized unit (CU) of a second network device, first configuration information indicating the first type of random access resource and the first status information for the first cell, and / or transmitting, to a second DU of the first network device, the first configuration information indicating the first type of random access resource and the first status information for the first cell.

[0171] In some example embodiments, the method 800 further comprises: receiving, from the first DU and in a setup request, first configuration information indicating the first type of random access resource and first status information, or receiving, from the first DU, the first status information in a configuration update message.

[0172] In some example embodiments, the first status information comprises a status switch indication of the first type of random access resource from being activated to being deactivated, or from being deactivated to being activated.

[0173] In some example embodiments, the method 800 further comprises: receiving, from a second CU of a second network device, second configuration information and second status information, the second configuration information indicating a further random access resource of the first type configured for a second cell in the second network device, the second status information indicating an activation status of the further random access resource of the first type within the second cell; and transmitting, to the first DU of the first network device, the second configuration information and the second status information for the second cell.

[0174] In some example embodiments, the method 800 further comprises: in accordance with a determination that the first type of random access resource is applied by the terminal device for the RA attempt, detecting whether there is a conflict in the first type of random access resources between the first cell and the second cell based on the first status information and the second status information; and performing a corrective action based on a detection of the conflict.

[0175] In some example embodiments, the second apparatus is or is comprised in a first CU of the first network device.

[0176] FIG. 9 shows a flowchart of an example method 900 implemented at a third apparatus in accordance with some example embodiments of the present disclosure. The third apparatus may be or may be comprised in a DU of a network device, e.g., the CU 112-1 of the network device 110-1. For the purpose of discussion, the method 900 will be described from the perspective of the third apparatus.

[0177] At block 910, the third apparatus transmits, to a first centralized unit (CU) of a first network device, first configuration information indicating a first type of random access resource configured for a first cell under a first distributed unit (DU) of the first network device.

[0178] At block 920, the third apparatus transmits, to the first CU, first status information for the first cell, the first status information indicating an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

[0179] In some example embodiments, the method 900 further comprises: in accordance with a determination that a status of the first type of random access resource is switched from being activated to being deactivated or from being deactivated to being activated, transmitting the first status information to the first CU.

[0180] In some example embodiments, the method 900 further comprises: transmitting, to the first DU and in a setup request, the first configuration information and first status information, or transmitting, to the first DU, the first status information in a configuration update message.

[0181] In some example embodiments, the first status information comprises a status switch indication of the first type of random access resource from being activated to being deactivated, or from being deactivated to being activated.

[0182] In some example embodiments, the method 900 further comprises: receiving, from the first CU of the first network device, second configuration information and second status information for a second cell in a second network device, the second configuration information indicating a further random access resource of the first type configured for the second cell, the second status information indicating an activation status of the further random access resource of the first type within the second cell.

[0183] In some example embodiments, the second apparatus is further caused to:receiving, from the first CU of the first network device, indication information indicating whether the first type of random access resource is applied by the terminal device for a random access attempt to the first cell; in accordance with a determination that the first type of random access resource is applied by the terminal device for the RA attempt, detecting whether there is a conflict in the first type of random access resources between the first cell and the second cell based on the first status information and the second status information; and performing a corrective action based on a detection of the conflict.

[0184] In some example embodiments, the third apparatus is or is comprised in a first distributed unit (DU) of the first network device.

[0185] FIG. 10 shows a flowchart of an example method 1000 implemented at a fourth apparatus in accordance with some example embodiments of the present disclosure. The fourth apparatus may be or may be comprised in a CU of a network device, e.g., the CU 112-2 of the network device 110-2. For the purpose of discussion, the method 1000 will be described from the perspective of the fourth apparatus.

[0186] At block 1010, the fourth apparatus receives, from a first centralized unit (CU) of a first network device, first configuration information and first status information, wherein the first configuration information indicating a random access resource of the first type configured for a first cell in a first distributed unit (DU) of the first network device, and the first status information indicates an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

[0187] In some example embodiments, at block 1020, the fourth apparatus may transmits, to the first CU of the first network device, second configuration information and second status information, the second configuration information indicating a further random access resource of the first type configured for a second cell in the second network device, the second status information indicating an activation status of the further random access resource of the first type within the second cell.

[0188] In some example embodiments, the method 1000 further comprises: in accordance with a determination that a status of the first type of random access resource is switched from being activated to being deactivated or from being deactivated to being activated, transmitting to the first CU of the first network device, an update to the second status information.

[0189] In some example embodiments, the method 1000 further comprises: receiving, from a second DU of the second network device, the second configuration information and the second status information.

[0190] In some example embodiments, the fourth apparatus is or is comprised in a second CU of the second network device.

[0191] In some example embodiments, a first apparatus capable of performing any of the method 700 (for example, the terminal device 120 in FIG. 1) may comprise means for performing the respective operations of the method 700. The means may be implemented in any suitable form and / or any of the described one or more example embodiments thereof. For example, the means may be implemented in a circuitry or software module. The first apparatus may be implemented as or included in the terminal device 120 in FIG.1.

[0192] In some example embodiments, the first apparatus comprises means for receiving, from a first distributed unit (DU) of a first network device, an indication of a change of an activation status of a first type of random access resource, wherein the first type of random access resource is configured for a first cell, and the activation status indicates whether the first type of random access resource is activated or deactivated for the first cell; and means for transmitting, to a first centralized unit (CU) of the first network device, indication information indicating whether the first type of random access resource is applied by the first apparatus for a random access attempt to the first cell.

[0193] In some example embodiments, the first apparatus further comprises means for perform other operations as described in the method 700.

[0194] In some example embodiments, a second apparatus capable of performing any of the method 800 (for example, a CU 112 of the network device 110 in FIG. 1) may comprise means for performing the respective operations of the method 800. The means may be implemented in any suitable form and / or any of the described one or more example embodiments thereof. For example, the means may be implemented in a circuitry or software module. The second apparatus may be implemented as or included in the CU 112 of the network device 110 in FIG. 1.

[0195] In some example embodiments, the second apparatus comprises means for receiving, from a terminal device, indication information indicating whether a first type of randomaccess resource is applied by the terminal device for a random access attempt to a first cell, wherein the first type of random access resource is configured for a first cell under a first distributed unit (DU) of a first network device, and the first type of random access resource is configured to be activated or deactivated over time by the first DU; and means for transmitting at least the indication information to the first DU.

[0196] In some example embodiments, the second apparatus further comprises means for perform other operations as described in the method 800.

[0197] In some example embodiments, a third apparatus capable of performing any of the method 900 (for example, the DU 114 of the network device 110 in FIG. 1) may comprise means for performing the respective operations of the method 900. The means may be implemented in any suitable form and / or any of the described one or more example embodiments thereof. For example, the means may be implemented in a circuitry or software module. The third apparatus may be implemented as or included in the DU 114 of the network device 110in FIG. 1.

[0198] In some example embodiments, the third apparatus comprises means for transmitting, to a first centralized unit (CU) of a first network device, first configuration information indicating a first type of random access resource configured for a first cell under a first distributed unit (DU) of the first network device; and means for transmitting, to the first CU, first status information for the first cell, the first status information indicating an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

[0199] In some example embodiments, the third apparatus further comprises means for perform other operations as described in the method 900.

[0200] In some example embodiments, a fourth apparatus capable of performing any of the method 1000 (for example, the CU 112 of the network device 110 in FIG. 1) may comprise means for performing the respective operations of the method 1000 The means may be implemented in any suitable form and / or any of the described one or more example embodiments thereof. For example, the means may be implemented in a circuitry or software module. The fourth apparatus may be implemented as or included in the CU 112 of the network device 110 in FIG. 1.

[0201] In some example embodiments, the fourth apparatus comprises means for receiving, from a first centralized unit (CU) of a first network device, first configuration information and first status information, wherein the first configuration information indicating a random access resource of the first type configured for a first cell in a first distributed unit (DU) of the first network device, and the first status information indicates an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

[0202] In some example embodiments, the fourth apparatus further comprises means for perform other operations as described in the method 1000.

[0203] FIG. 11 is a simplified block diagram of a device 1100 that is suitable for implementing example embodiments of the present disclosure. The device 1100 may be provided to implement a communication device, for example, the terminal device 120 or the network device 110, or the CU 112 or DU 114 in the network device 110 as shown in FIG. 1. As shown, the device 1100 includes one or more processors 1110, one or more memories 1120 coupled to the processor 1110, and one or more communication modules 1140 coupled to the processor 1110.

[0204] The communication module 1140 is for bidirectional communications. The communication module 1140 has one or more communication interfaces to facilitate communication with one or more other modules or devices. The communication interfaces may represent any interface that is necessary for communication with other network elements. In some example embodiments, the communication module 1140 may include at least one antenna.

[0205] The processor 1110 may be of any type suitable to the local technical network and may include one or more of the following: general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples. The device 1100 may have multiple processors, such as an application specific integrated circuit chip that is slaved in time to a clock which synchronizes the main processor.

[0206] The memory 1120 may include one or more non-volatile memories and one or more volatile memories. Examples of the non-volatile memories include, but are not limited to, a Read Only Memory (ROM) 1124, an electrically programmable read only memory (EPROM), a flash memory, a hard disk, a compact disc (CD), a digital video disk(DVD), an optical disk, a laser disk, and other magnetic storage and / or optical storage. Examples of the volatile memories include, but are not limited to, a random-access memory (RAM) 1122 and other volatile memories that will not last in the power-down duration.

[0207] A computer program 1130 includes computer executable instructions that are executed by the associated processor 1110. The instructions of the program 1130 may include instructions for performing operations / acts of some example embodiments of the present disclosure. The program 1130 may be stored in the memory, e.g., the ROM 1124. The processor 1110 may perform any suitable actions and processing by loading the program 1130 into the RAM 1122.

[0208] The example embodiments of the present disclosure may be implemented by means of the program 1130 so that the device 1100 may perform any process of the disclosure as discussed with reference to FIG. 3 to FIG. 10. The example embodiments of the present disclosure may also be implemented by hardware or by a combination of software and hardware.

[0209] In some example embodiments, the program 1130 may be tangibly contained in a computer readable medium which may be included in the device 1100 (such as in the memory 1120) or other storage devices that are accessible by the device 1100. The device 1100 may load the program 1130 from the computer readable medium to the RAM 1122 for execution. In some example embodiments, the computer readable medium may include any types of non-transitory storage medium, such as ROM, EPROM, a flash memory, a hard disk, CD, DVD, and the like. The term “non-transitory,” as used herein, is a limitation of the medium itself (i.e., tangible, not a signal) as opposed to a limitation on data storage persistency (e.g., RAM vs. ROM).

[0210] FIG. 12 shows an example of the computer readable medium 1200 which may be in form of CD, DVD or other optical storage disk. The computer readable medium 1200 has the program 1130 stored thereon.

[0211] Generally, various embodiments of the present disclosure may be implemented in hardware or special purpose circuits, software, logic or any combination thereof. Some aspects may be implemented in hardware, and other aspects may be implemented in firmware or software which may be executed by a controller, microprocessor or other computing device. Although various aspects of embodiments of the present disclosure areillustrated and described as block diagrams, flowcharts, or using some other pictorial representations, it is to be understood that the block, apparatus, system, technique or method described herein may be implemented in, as non-limiting examples, hardware, software, firmware, special purpose circuits or logic, general purpose hardware or controller or other computing devices, or some combination thereof.

[0212] Some example embodiments of the present disclosure also provide at least one computer program product tangibly stored on a computer readable medium, such as a non-transitory computer readable medium. The computer program product includes computerexecutable instructions, such as those included in program modules, being executed in a device on a target physical or virtual processor, to carry out any of the methods as described above. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

[0213] Program code for carrying out methods of the present disclosure may be written in any combination of one or more programming languages. The program code may be provided to a processor or controller of a general-purpose computer, special purpose computer, or other programmable data processing apparatus, such that the program code, when executed by the processor or controller, cause the functions / operations specified in the flowcharts and / or block diagrams to be implemented. The program code may execute entirely on a machine, partly on the machine, as a stand-alone software package, partly on the machine and partly on a remote machine or entirely on the remote machine or server.

[0214] In the context of the present disclosure, the computer program code or related data may be carried by any suitable carrier to enable the device, apparatus or processor to perform various processes and operations as described above. Examples of the carrier include a signal, computer readable medium, and the like.

[0215] The computer readable medium may be a computer readable signal medium or a computer readable storage medium. A computer readable medium may include but not limited to an electronic, magnetic, optical, electromagnetic, infrared, or semiconductorsystem, apparatus, or device, or any suitable combination of the foregoing. More specific examples of the computer readable storage medium would include an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random-access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or Flash memory), an optical fiber, a portable compact disc read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0216] Further, although operations are depicted in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. In certain circumstances, multitasking and parallel processing may be advantageous. Likewise, although several specific implementation details are contained in the above discussions, these should not be construed as limitations on the scope of the present disclosure, but rather as descriptions of features that may be specific to particular embodiments. Unless explicitly stated, certain features that are described in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, unless explicitly stated, various features that are described in the context of a single embodiment may also be implemented in a plurality of embodiments separately or in any suitable sub-combination.

[0217] Although the present disclosure has been described in languages specific to structural features and / or methodological acts, it is to be understood that the present disclosure defined in the appended claims is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example forms of implementing the claims.

Claims

WE CLAIM:

1. A first apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the first apparatus at least to:receive, from a first distributed unit (DU) of a first network device, an indication of a change of an activation status of a first type of random access resource, wherein the first type of random access resource is configured for a first cell, and the activation status indicates whether the first type of random access resource is activated or deactivated for the first cell; andtransmit, to a first centralized unit (CU) of the first network device, indication information indicating whether the first type of random access resource is applied by the first apparatus for a random access attempt to the first cell.

2. The first apparatus of claim 1, wherein the first apparatus is further caused to: receive, from the first CU of the first network device, configuration information associated with the first cell, the configuration information indicating the first type of random access resource configured for the first cell.

3. The first apparatus of claim 1 or 2, wherein the indication received from the first DU comprises a status switch indication of the first type of random access resource from being activated to being deactivated, or from being deactivated to being activated.

4. The first apparatus of any of claims 1 to 3, wherein the first apparatus is further caused to:transmit, to the first CU of the first network device, timeline information indicating at least one of the following:at least one time period when the first type of random access resource is activated, orat least one time period when the first type of random access resource are deactivated.

5. The first apparatus of any of claims 1 to 4, wherein the indication information comprises: for a random access attempt to the first cell,a first value to indicate that the first type of random access resource is applied by the first apparatus for the random access attempt, ora second value to indicate that a second type of random access resource is applied by the first apparatus for the random access attempt, the second type of random access resource being configured to be statically activated.

6. The first apparatus of any of claims 1 to 5, wherein the first apparatus is caused to: transmit, to the first CU of the first network device, a physical random access channel report comprising the indication information.

7. The first apparatus of any of claims 1 to 6, wherein the first apparatus is or is comprised in a terminal device.

8. A second apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to:receive, from a terminal device, indication information indicating whether a first type of random access resource is applied by the terminal device for a random access attempt to a first cell, wherein the first type of random access resource is configured for a first cell under a first distributed unit (DU) of a first network device, and the first type of random access resource is configured to be activated or deactivated over time by the first DU; andtransmit at least the indication information to the first DU.

9. The second apparatus of claim 8, wherein the second apparatus is further caused to: transmit, to the terminal device, configuration information associated with the first cell, the configuration information indicating the first type of random access resource configured for the first cell.

10. The second apparatus of claim 8 or 9, wherein the second apparatus is further caused to:determine timeline information for the first type of random access resource, the timeline information indicating at least one of the following:at least one time period when the first type of random access resource is to be activated, orat least one time period when the first type of random access resource is to be deactivated; andtransmit the timeline information and the indication information to the first DU.

11. The second apparatus of claim 8 or 9, wherein the second apparatus is further caused to:receive, from the terminal device, further timeline information indicating at least one of the following:at least one time period when the first type of random access resource is activated, orat least one time period when the first type of random access resource is deactivated.

12. The second apparatus of any of claims 8 to 11, wherein the indication information comprises: for a random access attempt to the first cell,a first value to indicate that the first type of random access resource is applied by the first apparatus for the random access attempt, ora second value to indicate that a second type of random access resource is applied by the first apparatus for the random access attempt, the second type of random access resource being configured to be statically activated.

13. The second apparatus of any of claims 8 to 12, wherein the second apparatus is caused to:receive, from the terminal device, a physical random access channel report comprising the indication information.

14. The second apparatus of any of claims 8 to 13, wherein the second apparatus is further caused to:receive, from the first DU, first status information for the first cell indicating an activation status of the first type of random access resource, the activation status indicatingwhether the first type of random access resource is activated or deactivated for the first cell.

15. The second apparatus of claim 14, wherein the second apparatus is further caused to:transmit, to a second centralized unit (CU) of a second network device, first configuration information indicating the first type of random access resource and the first status information for the first cell, and / ortransmit, to a second DU of the first network device, the first configuration information indicating the first type of random access resource and the first status information for the first cell.

16. The second apparatus of claim 14 or 15, wherein the second apparatus is further caused to:receive, from the first DU and in a setup request, first configuration information indicating the first type of random access resource and first status information, or receive, from the first DU, the first status information in a configuration update message.

17. The second apparatus of any of claims 14 to 16, wherein the first status information comprises a status switch indication of the first type of random access resource from being activated to being deactivated, or from being deactivated to being activated.

18. The second apparatus of any of claims 14 to 17, wherein the second apparatus is further caused to:receive, from a second CU of a second network device, second configuration information and second status information, the second configuration information indicating a further random access resource of the first type configured for a second cell in the second network device, the second status information indicating an activation status of the further random access resource of the first type within the second cell; andtransmit, to the first DU of the first network device, the second configuration information and the second status information for the second cell.

19. The second apparatus of claim 18, wherein the second apparatus is further caused to:in accordance with a determination that the first type of random access resource isapplied by the terminal device for the RA attempt, detect whether there is a conflict in the first type of random access resources between the first cell and the second cell based on the first status information and the second status information; andperform a corrective action based on a detection of the conflict.

20. The second apparatus of any of claims 8 to 19, wherein the second apparatus is or is comprised in a first CU of the first network device.

21. A third apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to:transmit, to a first centralized unit (CU) of a first network device, first configuration information indicating a first type of random access resource configured for a first cell under a first distributed unit (DU) of the first network device; and transmit, to the first CU, first status information for the first cell, the first status information indicating an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

22. The third apparatus of claim 21, wherein the third apparatus is caused to:in accordance with a determination that a status of the first type of random access resource is switched from being activated to being deactivated or from being deactivated to being activated, transmit the first status information to the first CU.

23. The third apparatus of claim 21 or 22, wherein the third apparatus is caused to: transmit, to the first DU and in a setup request, the first configuration information and first status information, ortransmit, to the first DU, the first status information in a configuration update message.

24. The third apparatus of any of claims 21 to 23, wherein the first status information comprises a status switch indication of the first type of random access resource from being activated to being deactivated, or from being deactivated to being activated.

25. The third apparatus of any of claims 21 to 24, wherein the third apparatus is further caused to:receive, from the first CU of the first network device, second configuration information and second status information for a second cell in a second network device, the second configuration information indicating a further random access resource of the first type configured for the second cell, the second status information indicating an activation status of the further random access resource of the first type within the second cell.

26. The third apparatus of any of claims 21 to 25, wherein the second apparatus is further caused to:receive, from the first CU of the first network device, indication information indicating whether the first type of random access resource is applied by the terminal device for a random access attempt to the first cell;in accordance with a determination that the first type of random access resource is applied by the terminal device for the RA attempt, detect whether there is a conflict in the first type of random access resources between the first cell and the second cell based on the first status information and the second status information; andperform a corrective action based on a detection of the conflict.

27. The third apparatus of any of claims 21 to 26, wherein the third apparatus is or is comprised in a first distributed unit (DU) of the first network device.

28. A fourth apparatus comprising:at least one processor; andat least one memory storing instructions that, when executed by the at least one processor, cause the second apparatus at least to:receive, from a first centralized unit (CU) of a first network device, first configuration information and first status information, wherein the first configuration information indicating a random access resource of the first type configured for a first cell in a first distributed unit (DU) of the first network device, and the first status information indicates an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

29. The fourth apparatus of claim 28, wherein the fourth apparatus is further caused to: transmit, to the first CU of the first network device, second configuration information and second status information, the second configuration information indicating a further random access resource of the first type configured for a second cell in the second network device, the second status information indicating an activation status of the further random access resource of the first type within the second cell.

30. The fourth apparatus of claim 29, wherein the fourth apparatus is further caused to: in accordance with a determination that a status of the first type of random access resource is switched from being activated to being deactivated or from being deactivated to being activated, transmit, to the first CU of the first network device, an update to the second status information.

31. The fourth apparatus of claim 29 or 30, wherein the fourth apparatus is further caused to:receive, from a second DU of the second network device, the second configuration information and the second status information.

32. The fourth apparatus of any of claims 28 to 31, wherein the fourth apparatus is or is comprised in a second CU of the second network device.

33. A method comprising:receiving, from a first distributed unit (DU) of a first network device, an indication of a change of an activation status of a first type of random access resource, wherein the first type of random access resource is configured for a first cell, and the activation status indicates whether the first type of random access resource is activated or deactivated for the first cell; andtransmitting, to a first centralized unit (CU) of the first network device, indication information indicating whether the first type of random access resource is applied by the first apparatus for a random access attempt to the first cell.

34. A method comprising:receiving, from a terminal device, indication information indicating whether a first type of random access resource is applied by the terminal device for a random access attempt to afirst cell, wherein the first type of random access resource is configured for a first cell under a first distributed unit (DU) of a first network device, and the first type of random access resource is configured to be activated or deactivated over time by the first DU; andtransmitting at least the indication information to the first DU.

35. A method comprising:transmitting, to a first centralized unit (CU) of a first network device, first configuration information indicating a first type of random access resource configured for a first cell under a first distributed unit (DU) of the first network device; andtransmitting, to the first CU, first status information for the first cell, the first status information indicating an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

36. A method comprising:receiving, from a first centralized unit (CU) of a first network device, first configuration information and first status information, wherein the first configuration information indicating a random access resource of the first type configured for a first cell in a first distributed unit (DU) of the first network device, and the first status information indicates an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

37. A first apparatus comprising:means for receiving, from a first distributed unit (DU) of a first network device, an indication of a change of an activation status of a first type of random access resource, wherein the first type of random access resource is configured for a first cell, and the activation status indicates whether the first type of random access resource is activated or deactivated for the first cell; andmeans for transmitting, to a first centralized unit (CU) of the first network device, indication information indicating whether the first type of random access resource is applied by the first apparatus for a random access attempt to the first cell.

38. A second apparatus comprising:means for receiving, from a terminal device, indication information indicating whethera first type of random access resource is applied by the terminal device for a random access attempt to a first cell, wherein the first type of random access resource is configured for a first cell under a first distributed unit (DU) of a first network device, and the first type of random access resource is configured to be activated or deactivated over time by the first DU; and means for transmitting at least the indication information to the first DU.

39. A third apparatus comprising:means for transmitting, to a first centralized unit (CU) of a first network device, first configuration information indicating a first type of random access resource configured for a first cell under a first distributed unit (DU) of the first network device; andmeans for transmitting, to the first CU, first status information for the first cell, the first status information indicating an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

40. A fourth apparatus comprising:means for receiving, from a first centralized unit (CU) of a first network device, first configuration information and first status information, wherein the first configuration information indicating a random access resource of the first type configured for a first cell in a first distributed unit (DU) of the first network device, and the first status information indicates an activation status of the first type of random access resource, the activation status indicating whether the first type of random access resource is activated or deactivated for the first cell.

41. A computer readable medium comprising instructions stored thereon for causing an apparatus at least to perform the method of claim 33 or the method of claim 34 or the method of claim 35 or the method of claim 36.

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