Improved physical downlink control channel (PDCCH) order for physical random access channel (PRACH) transmission in lower layer triggered mobility (LTM)

Abstract

Embodiments of the present disclosure provide a method for improving PRACH transmission by PDCCH order in lower-layer trigger mobility. The method includes the step of receiving a PDCCH order to initiate a PRACH transmission to at least one cell. The method includes the step of decoding a PRACH transmission index value, the PRACH transmission index value indicating whether the PRACH transmission is the first transmission or a retransmission, and the PRACH transmission index value is associated with a target downlink reference signal. The method includes the step of determining an RA preamble power ramping counter value. The method includes the step of transmitting a PRACH transmission to at least one cell, partly based on a PRACH transmission power level, the PRACH transmission power level being determined partly based on an RA preamble power ramping counter value.

Description

[Technical Field]

[0001] Exemplary embodiments of this disclosure relate generally to communication systems, and more particularly to user equipment (UE) power ramping procedures for PRACH transmission in PDCCH order. [Background technology]

[0002] The 3rd Generation Partnership Project (3GPP) Fifth Generation (5G) technology is a next-generation wireless system and network architecture capable of providing ultra-high-speed broadband and ultra-robust, low-latency connectivity. 5G technology improves the variety of telecommunications services offered to end users and supports massive broadband, providing gigabytes per second of bandwidth on demand for uplink and downlink transmissions. As an example, a next-generation communication system may be configured to use virtualized radio access network (RAN) and core network functions. As another example, a next-generation system may use a service-based architecture (SBA), for example, a system architecture where system functionality is achieved using a set of NFs (Network Functions) that serve other network functions (NFs) authorized to access a service. A 5G network may be configured to support NFs via a network repository function (NRF). For example, an NRF may be configured to maintain a list of available NFs to facilitate the registration and / or discovery of services in instances where a user equipment (UE) attempts to access one or more services provided by one or more network devices.

[0003] A 3GPP 5G communication system employs a vast network of RAN nodes (e.g., next-generation node B, also known as gNB) that generate networking cells to service one or more user devices (UEs) (e.g., mobile computing devices such as smartphones and laptops). When a particular UE traverses a real-world environment associated with a network of RAN nodes (e.g., gNBs), the UE may need to connect to multiple RAN nodes, and therefore the UE must be able to efficiently perform a "cell switch," also known as a handover from a first network cell (e.g., source cell) associated with a first RAN node to a second network cell (e.g., target cell) associated with a second RAN node. However, during cell switching, various uplink (UL) and downlink (DL) transmission timing errors and / or synchronization errors can occur between the UE and one or more RAN nodes. Therefore, it is desirable to have an improved method for efficiently synchronizing data transmission between the UE and one or more RAN nodes associated with one or more networking cells of a particular 3GPP 5G communication system. [Overview of the project]

[0004] Methods, apparatus, and computer program products are provided according to exemplary embodiments for providing physical random access channel (PRACH) transmission with improved physical downlink control channel (PDCCH) order in lower layer triggered mobility (LTM).

[0005] A first aspect of this disclosure provides a computer implementation method for providing PRACH transmissions with an improved PDCCH order in LTM. The computer implementation method can be performed by one or more specially configured computing devices, which are embodied, for example, by hardware, software, firmware, and / or any combination thereof, as described herein. In one exemplary embodiment, the computer implementation method includes receiving a first PDCCH order from a network element to initiate a PRACH transmission to at least one cell. The computer implementation method also includes decoding a PRACH transmission index value associated with the first PDCCH order, the PRACH transmission index value indicating whether the PRACH transmission is an initial transmission or a retransmission, and the PRACH transmission index value is associated with a target DL RS indicated by a downlink (DL) reference signal (RS) index associated with the first PDCCH order. The computer implementation method also includes determining a random access (RA) preamble power ramping counter value, in part, on at least one of the PRACH transmission index value or the target DL RS. The computer implementation method also includes sending a PRACH transmission to at least one cell, partly based on a PRACH transmission power level, which is determined partly based on an RA preamble power ramping counter value.

[0006] The computer implementation method further includes setting the RA preamble power ramping counter value to a predetermined initial counter value in response to the determination that the PRACH transmit index value associated with a first PDCCH order indicates a retransmission associated with a first target DL RS, and in response to the determination that the device has not performed the first PRACH transmit associated with the first target DL RS.

[0007] The computer implementation method further includes incrementing the RA preamble power ramping counter value to a predetermined value associated with the first retransmission in response to the determination that the PRACH transmit index value associated with the first PDCCH order indicates a retransmission associated with the first target DL RS, and in response to the determination that the device has not performed the first PRACH transmit associated with the first target DL RS.

[0008] The computer implementation method further includes the step of setting the RA preamble power ramping counter value to the latest value associated with the second PDCCH order that is associated with the same LTM candidate cell and at least one PRACH transmission associated with the first target DL RS, in response to the determination that the PRACH transmission index value associated with the first PDCCH order indicates a retransmission associated with the first target DL RS, in response to the determination that the device has performed at least one or more PRACH transmissions associated with the first target DL RS, and in response to the receipt of a second PDCCH order indicating a retransmission associated with the second target DL RS.

[0009] The computer implementation method further includes the step of incrementing the RA preamble power ramping counter value from the latest value associated with the second PDCCH order that is associated with the same cell and at least one PRACH transmission associated with the first target DL RS, in response to the determination that the PRACH transmission index value associated with the first PDCCH order indicates a retransmission associated with the first target DL RS, in response to the determination that the device has performed at least one or more PRACH transmissions associated with the first target DL RS, and in response to the reception of a second PDCCH order indicating a retransmission associated with the second target DL RS.

[0010] In response to determining that a PRACH transmission index value associated with a first PDCCH order indicates a retransmission associated with a first target DL RS, and in response to determining that the apparatus has performed at least one or a plurality of PRACH transmissions associated with the first target DL RS, and in response to receiving a second PDCCH order indicating a retransmission associated with a second target DL RS, the computer-implemented method further includes resetting a RA preamble power ramping counter value, where the second PDCCH order is associated with the same cell.

[0011] The computer-implemented method further includes that the first PDCCH order is composed of a DCI format associated with one or more downlink control information (DCI) data fields, and one or more DCI data fields include data related to at least one of an indication of LTM candidate cell identification information, a DL RS index, a RACH opportunity, a RA preamble index, a PRACH transmission index, or a RA response (RAR) configuration indication.

[0012] The computer-implemented method further includes that the first PDCCH order indicates that no RAR is set.

[0013] [[ID=The number of active RA preamble power ramping counters that the apparatus can maintain is determined by one or more computing capabilities associated with the apparatus, and the active RA preamble power ramping counters are associated with respective PDCCH orders received by the apparatus.

[0014] The computer-implemented method further includes determining whether the number of active RA preamble power ramping counters associated with a device exceeds one or more computing capabilities associated with the device. The computer-implemented method also includes, in response to determining that the number of active RA preamble power ramping counters associated with a device exceeds one or more computing capabilities of the device, ending the oldest active RA preamble power ramping counter associated with the active RA preamble power ramping counters.

[0015] The computer-implemented method further includes being configured to instruct a device to obtain a timing advance value such that a first PDCCH order is associated with at least one cell, and the timing advance value is used in a cell switching procedure configured to switch the device to at least one cell.

[0016] The computer-implemented method further includes determining that a PRACH transmission power level is determined at least in part based on inputting a RA preamble power ramping counter value into a power ramping model.

[0017] A second aspect of this disclosure provides another computer implementation method for providing PRACH transmissions with an improved PDCCH order in LTM. The computer implementation method can be performed by one or more specially configured computing devices, which are embodied, for example, by hardware, software, firmware, and / or any combination thereof, as described herein. In one exemplary embodiment, the computer implementation method includes the step of generating a PDCCH order configured to cause a user device (UE) to initiate a PRACH transmission to at least one cell, the PDCCH order configured to instruct the UE to obtain a timing advance value associated with at least one cell. The computer implementation method also includes the step of determining a target downlink (DL) reference signal (RS). The computer implementation method also includes the step of encoding a DL RS index associated with the PDCCH order, based in part on the DL RS. The computer implementation method also includes the step of encoding a PRACH transmission index using a PRACH transmission index value indicating whether the PRACH transmission is the first transmission or a retransmission, the PRACH transmission index value associated with the DL RS. The computer implementation method also includes the step of sending a PDCCH order to the UE.

[0018] The computer implementation method further includes the step of receiving one or more PRACH transmissions from the UE in response to the step of causing a PDCCH order to be sent to the UE, each of the one or more PRACH transmissions comprising at least its own random access (RA) preamble.

[0019] The computer implementation method further comprises a PDCCH order consisting of a Downlink Control Information (DCI) format associated with one or more DCI data fields, wherein one or more DCI data fields contain data associated with at least one of the following: an LTM candidate cell identification information instruction, a DL RS index, a RACH opportunity, an RA preamble index, a PRACH transmission index, or an RA response (RAR) configuration instruction.

[0020] The computer implementation method further includes indicating that the PDCCH order does not have a RAR set.

[0021] The computer implementation method further includes using a timing advance value obtained as a result of at least a first PDCCH order for a cell switching procedure configured to switch the device to at least one cell.

[0022] A third aspect of this disclosure provides an apparatus for providing PRACH transmission in an improved PDCCH order in LTM. In one exemplary embodiment, the apparatus includes at least one or more transceivers and at least one or more processors communicatively coupled to one or more transceivers. The one or more processors are configured to cause the apparatus to perform one of the exemplary computer implementation methods described herein.

[0023] A fourth aspect of this disclosure provides a computer program product for providing PRACH transmission in an improved PDCCH order in LTM. In one exemplary embodiment, the computer program product includes at least one non-temporary computer-readable storage medium storing computer program code instructions that constitute the computer program product for performing one of the exemplary computer implementation methods described herein when executed by at least one processor.

[0024] A fifth aspect of this disclosure provides an apparatus for PRACH transmission by an improved PDCCH order in LTM. The apparatus includes means for receiving a first PDCCH order from a network element to initiate a PRACH transmission to at least one cell. The apparatus also includes means for decoding a PRACH transmission index value associated with the first PDCCH order, the PRACH transmission index value indicating whether the PRACH transmission is an initial transmission or a retransmission, and the PRACH transmission index value is associated with a target DL RS indicated by a downlink (DL) reference signal (RS) index associated with the first PDCCH order. The apparatus also includes means for determining a random access (RA) preamble power ramping counter value, in part, based on at least one of the PRACH transmission index value or the target DL RS. The apparatus also includes means for transmitting a PRACH transmission to at least one cell, in part, based on a PRACH transmission power level, the PRACH transmission power level being determined in part on an RA preamble power ramping counter value.

[0025] The device further includes means for setting the RA preamble power ramping counter value to a predetermined initial counter value in response to the determination that the PRACH transmit index value associated with a first PDCCH order indicates a retransmission associated with a first target DL RS, and in response to the determination that the device has not performed the first PRACH transmit associated with the first target DL RS.

[0026] The device further includes means for incrementing an RA preamble power ramping counter value to a predetermined value associated with a first retransmission in response to the determination that a PRACH transmit index value associated with a first PDCCH order indicates a retransmission associated with a first target DL RS, and in response to the determination that the device has not performed the first PRACH transmit associated with the first target DL RS.

[0027] The device further includes means for setting the RA preamble power ramping counter value to the latest value associated with the at least one PRACH transmission associated with the first target DL RS, in response to the determination that the PRACH transmission index value associated with the first PDCCH order indicates a retransmission associated with the first target DL RS, and in response to the reception of a second PDCCH order indicating a retransmission associated with the second target DL RS, the second PDCCH order being associated with the same LTM candidate cell.

[0028] The device further includes means for determining that the PRACH transmit index value associated with a first PDCCH order indicates a retransmission associated with a first target DL RS, determining that the device has performed at least one or more PRACH transmits associated with a first target DL RS, and receiving a second PDCCH order indicating a retransmission associated with a second target DL RS, such that the second PDCCH order is associated with the same cell and the RA preamble power ramping counter value is incremented from the most recent value associated with at least one or more PRACH transmits associated with the first target DL RS.

[0029] The device further includes means for resetting the RA preamble power ramping counter value, in response to the device determining that it has performed at least one or more PRACH transmissions associated with the first target DL RS in response to the device determining that the PRACH transmission index value associated with the first PDCCH order indicates a retransmission associated with the first target DL RS, and in response to receiving a second PDCCH order indicating a retransmission associated with the second target DL RS, the second PDCCH order is associated with the same cell.

[0030] The device further includes means wherein a first PDCCH order is configured in a downlink control information (DCI) format associated with one or more DCI data fields, and the one or more DCI data fields comprise data associated with at least one of the following: an LTM candidate cell identification information instruction, a DL RS index, a RACH opportunity, an RA preamble index, a PRACH transmission index, or an RA response (RAR) configuration instruction.

[0031] The device further includes means for indicating that the first PDCCH order does not have a RAR set.

[0032] The apparatus further includes means by which the number of active RA preamble power rampping counters that the apparatus can maintain is determined by one or more computing powers associated with the apparatus, and the active RA preamble power rampping counters are associated with one or more respective PDCCH orders received by the apparatus.

[0033] The device further includes means for determining whether the number of active RA preamble power rampping counters associated with the device exceeds one or more computing powers associated with the device. The device also includes means for terminating the oldest active RA preamble power rampping counter associated with an active RA preamble power rampping counter in response to determining that the number of active RA preamble power rampping counters associated with the device exceeds one or more computing powers of the device.

[0034] The apparatus is configured such that a first PDCCH order instructs the apparatus to obtain a timing advance value associated with at least one cell, and further includes means used for a cell switching procedure configured to switch the apparatus to at least one cell.

[0035] The device further includes means by which the PRACH transmit power level is determined in part based on inputting the RA preamble power ramping counter value into the power ramping model.

[0036] A sixth aspect of this disclosure provides another apparatus that provides PRACH transmissions by an improved PDCCH order in LTM. The apparatus includes means for generating a PDCCH order configured to cause a user apparatus (UE) to initiate a PRACH transmission to at least one cell, the PDCCH order being configured to instruct the UE to obtain a timing advance value associated with at least one cell. The apparatus also includes means for determining a target downlink (DL) reference signal (RS). The apparatus also includes means for encoding a DL RS index associated with a PDCCH order, based in part on the DL RS. The apparatus also includes means for encoding a PRACH transmission index using a PRACH transmission index value indicating whether the PRACH transmission is the first transmission or a retransmission, the PRACH transmission index value being associated with the DL RS. The apparatus also includes means for transmitting a PDCCH order to a UE.

[0037] The device further includes means for receiving one or more PRACH transmissions from a UE in response to causing the UE to send a PDCCH order, each of the one or more PRACH transmissions comprising at least its own random access (RA) preamble.

[0038] The apparatus further includes means such that a PDCCH order is comprised of a Downlink Control Information (DCI) format associated with one or more DCI data fields, and one or more DCI data fields comprise data associated with at least one of the following: an LTM candidate cell identification information instruction, a DL RS index, a RACH opportunity, an RA preamble index, a PRACH transmission index, or an RA response (RAR) configuration instruction.

[0039] The apparatus further includes means for indicating that the PDCCH order does not have a RAR set.

[0040] The apparatus further includes means used in a cell switching procedure configured to switch the apparatus to at least one cell, where the timing advance value obtained as a result of at least a first PDCCH order is used. [Brief explanation of the drawing]

[0041] Having thus provided a general overview of specific exemplary embodiments, I now refer to the attached drawings, which are not necessarily drawn to scale.

[0042] [Figure 1] This is a block diagram of a communication system configured according to one or more exemplary embodiments of the present disclosure. [Figure 2] This is a block diagram of a device that may be configured to provide physical random access channel (PRACH) transmission in lower layer trigger mobility (LTM) with improved physical downlink control channel (PDCCH) order, according to one or more exemplary embodiments of the present disclosure. [Figure 3A] This flowchart shows a method for PRACH transmission in an improved order in LTM according to one or more exemplary embodiments of the present disclosure. [Figure 3B] This flowchart shows a method for PRACH transmission in an improved order in LTM according to one or more exemplary embodiments of the present disclosure. [Figure 4] This flowchart shows a method for PRACH transmission in an improved order for a user device (UE) according to one or more exemplary embodiments of the present disclosure. [Figure 5] This flowchart shows a method for PRACH transmission in an improved order for network elements according to one or more exemplary embodiments of the present disclosure. [Modes for carrying out the invention]

[0043] Some embodiments of this disclosure are described below in more detail with reference to the accompanying drawings, which illustrate some, though not all, embodiments of this disclosure. In fact, various embodiments of this disclosure may be embodied in many different forms and should not be construed as being limited to the embodiments described herein. Rather, these embodiments are provided so as to satisfy the applicable legal requirements of this disclosure. Similar reference numbers refer to similar elements throughout. As used herein, the terms “data,” “content,” “information,” and similar terms may be used interchangeably to refer to data that can be transmitted, received, and / or stored in accordance with embodiments of this disclosure. Accordingly, the use of any such terms should not be construed as limiting the spirit and scope of embodiments of this disclosure.

[0044] Furthermore, as used herein, the term “circuit” means (a) a hardware-only circuit implementation (e.g., implementations in analog and / or digital circuits), (b) a combination of a circuit and a computer program product including software and / or firmware instructions stored in one or more computer-readable memories, wherein the one or more computer-readable memories cooperate to cause the device to perform one or more functions described herein, and (c) a circuit such as a microprocessor or part of a microprocessor that requires software or firmware for operation even if the software or firmware is not physically present. This definition of “circuit” applies to all uses of the term herein, including in any claim. As a further example, the term “circuit” as used herein also includes implementations comprising one or more processors and / or parts thereof and accompanying software and / or firmware. As defined herein, “computer-readable storage medium” (e.g., volatile or non-volatile memory devices) can be distinguished from “computer-readable transmission medium” (e.g., electromagnetic signals).

[0045] Furthermore, as used herein, the terms “source cell,” “serving cell,” and / or “LTM serving cell” are interchangeable to refer to the network cell associated with each RAN node (e.g., gNB) to which the UE is currently connected. Similarly, the terms “candidate cell,” “target cell,” and / or “LTM candidate cell” are interchangeable to refer to the network cell associated with each RAN node (e.g., gNB) to which the UE can potentially connect. Moreover, as described herein, various transmissions (e.g., PRACH transmissions) are generally described as being sent to a specific cell (e.g., a serving cell, a candidate cell, etc.). Sending data to a specific cell will be understood as sending data to one or more networking elements, network nodes (e.g., RAN nodes, gNBs, etc.), and / or any other computing devices capable of generating, enhancing, maintaining, managing, and / or otherwise integrating a specific cell for the purpose of facilitating communication over the communication network (e.g., a 5G network) associated with that specific cell.

[0046] The exemplary communication systems, frameworks, and / or associated techniques of this disclosure may be configured to provide improved physical downlink control channel (PDCCH) order physical random access channel (PRACH) transmissions in lower layer triggered mobility (LTM). Additionally or alternatively, the disclosure may provide techniques for enhancing PDCCH order RACH transmissions for multiple timing advance (TA) operations (e.g., intra-cell and / or inter-cell TA operations), where multiple TA values ​​may be maintained for serving cells. For example, multiple TAs may be maintained and / or utilized for multiple transmit and receive point (TRP) communications, where uplink (UL) transmissions may be associated with a first or second TA value. However, it should be understood that this disclosure is not limited to the specific type of communication system and / or process disclosed. For example, while demonstrated in the context of wireless cellular systems utilizing 3GPP system elements such as 3GPP Next Generation Core Networks, the disclosed embodiments can be readily adapted to various other types of communication systems. In addition, while this disclosure may describe specific embodiments in conjunction with 5G communication systems, other embodiments are also applicable to and include other networks and network technologies such as 3G, 4G, Long-Term Evolution (LTE), and 6G, without limitation.

[0047] According to exemplary embodiments implemented in a 5G communication system environment, one or more 3GPP standards, specifications, and / or protocols provide further descriptions of user equipment (UE) and core network elements / entities / functions, and / or the operations performed by the UE and core network elements / entities / functions (e.g., 3GPP System Aspect (SA) Working Group 5 (3GPP SA5), 3GPP RAN3, etc.). Other 3GPP standards, specifications, and / or protocols provide other conventional details that will be understood by those skilled in the art. However, while exemplary embodiments are well suited to implementations associated with the 3GPP standards described above, alternative embodiments are not necessarily intended to be limited to any particular standard.

[0048] Embodiments of this disclosure generally relate to new radio (NR) mobility extensions, and more specifically to Layer 1 / Layer 2 (L1 / L2) based inter-cell mobility, also known as lower-layer triggered mobility (LTM). Furthermore, any extension disclosed herein may be applied to multiple TA operations (e.g., within a single serving cell). When a particular UE traverses between network cells associated with one or more RAN nodes (e.g., one or more gNBs), a cell switching procedure (also known as a handover procedure) is performed to switch the UE from the serving cell (the current network cell, also known as the source cell) to a candidate cell (also known as the target cell). According to current 3GPP specifications, handovers are currently based on Layer 3 (L3) network measurement and radio resource control (RRC) signaling. However, to reduce the latency, overhead, and service downtime commonly associated with L3-based mobility management, embodiments of this disclosure optimize, configure, and / or further improve one or more features of NR LTM.

[0049] One such area that could be improved is TA management, where the UE may be configured to acquire the TA value of at least one candidate network cell (e.g., a target LTM candidate cell) before executing a cell switching command configured to switch the UE from the current source cell (e.g., a serving cell) associated with the UE to a candidate network cell. This process is known as early TA acquisition and may be performed using a random access (RA) procedure in PDCCH order. TA can be understood as a command and / or configuration sent and / or provided to the UE from a specific RAN node (e.g., a gNB) that allows the UE to apply and / or adjust (or readjust) the timing of UL transmissions associated with the UE to match the downlink (DL) subframe timing of the communication network (e.g., a 5G network, a 6G network, or a later network). Thus, the TA acquisition process works to synchronize UL transmissions to DL transmission timing between the UE and a specific RAN node (e.g., a gNB).

[0050] As described herein, TA acquisition may be performed as part of a PDCCH order issued by a RAN node (e.g., a gNB). Generally, PDCCH orders can be used to synchronize transmissions between a particular UE and a particular RAN node (e.g., a gNB) and may be issued to a UE for a variety of reasons. For example, a gNB may issue a PDCCH order to a UE when the gNB and the UE are not synchronized (e.g., the UE does not have uplink timing), or, as further described herein, during / before a UE handover from a serving cell to a candidate cell. In some contexts, a PDCCH order may cause the UE to initiate a PRACH transmission (e.g., a transmission of a random access (RA) preamble) in order to achieve synchronization between the UE and the gNB.

[0051] In various embodiments, a PDCCH order may consist of a Downlink Control Information (DCI) format (e.g., DCI format1_0). The DCI, also described as a DCI message and / or DCI payload, comprises control information used to schedule physical resources for DL ​​and / or UL transmissions between the UE and a RAN node serving a particular network cell (e.g., an LTM candidate cell). One or more DCIs may comprise various DCI fields (e.g., data fields) depending on the specific format associated with the one or more DCIs. Examples of information that may be contained in the various DCI fields associated with a PDCCH order include, but are not limited to, a DCI format identifier, frequency domain resource allocation, RA preamble index, UL / auxiliary UL indicator, synchronization signal (SS) / physical broadcast channel (PBCH) index, PRACH mask index, PRACH transmit index, identification information related to the candidate cell, DL reference signal (RS) index, SS block (SSB) index, information regarding RACH opportunities, and RA response (RAR) configuration instructions (e.g., whether the UE expects a RAR transmission from the RAN node).

[0052] Based on the PDCCH order, the UE can perform a PRACH transmission to the RAN node (e.g., gNB) associated with the network cell (e.g., LTM candidate cell) indicated by the PDCCH order. However, the UE must determine the transmit power required to successfully perform the PRACH transmission, and therefore can perform a power ramping procedure to determine the correct transmit power.

[0053] According to the current 3GPP specification, the UE transmits power (PRACH) on the active UL bandwidth portion (BWP) b of the carrier f of serving cell c based on DL RS for serving cell c in the transmit opportunity i. PRACH,b,f,c (i)) P PRACH,b,f,c (i) = {P CMAX,f,c (i), PPRACH,target,f,c +PL b,f,c} can be determined in [dBm], where P CMAX,f,c (i) is the UE-configured maximum output power defined for carrier f of serving cell c within transmission opportunity i, and P PRACH,target,f,c is the PRACH target received power PREAMBLE_RECEIVED_TARGET_POWER provided by the upper layer for the active UL BWP b of carrier f of serving cell c, and PL b,f,c is the path loss for active UL BWP b of carrier f, calculated by the UE in dB as (referenceSignalPower - upper layer filtered reference signal received power (RSRP)) [dBm] based on the DL RS associated with the PRACH transmission on the active DL BWP of serving cell c. When the active DL BWP is the initial DL BWP and in the case of SS / PBCH block and CORESET multiplexing pattern 2 or 3, the UE determines PL b,f,c based on the SS / PBCH block associated with the PRACH transmission. When the PRACH transmission from the UE responds to the detection of a PDCCH order by the UE triggering a contention-free RA procedure and the demodulation reference signal (DM-RS) of the PDCCH order depends on the quasi-collocated DL RS, referenceSignalPower is provided by ss-PBCH-BlockPower.

[0054] The current 3GPP specifications also provide a legacy PRACH power ramping procedure, in which a media access control (MAC) layer entity can determine for each RA preamble as follows. a. When PREAMBLE_TRANSMISSION_COUNTER is greater than 1, and b. When no notification of interruption of the power ramping counter has been received from the lower layer, and c. When no listen before talk (LBT) failure indication for the most recent RA preamble transmission has been received from the lower layer, and ​d. If the selected SS block (SSB) or CSI-RS has not changed from the selection in the most recent RA preamble transmission, i. Increment PREAMBLE_POWER_RAMPING_COUNTER by 1. e. Select the value of DELTA_PREAMBLE according to Section 7.3. f. Set PREAMBLE_RECEIVED_TARGET_POWER to preambleReceivedTargetPower+DELTA_PREAMBLE+(PREAMBLE_POWER_RAMPING_COUNTER-1)×PREAMBLE_POWER_RAMPING_STEP+POWER_OFFSET_2STEP_RA.

[0055] As described herein, the power ramping procedure for PRACH transmission to a serving cell can be found in the current 3GPP specification. However, the power ramping procedure for PRACH transmission by PDCCH order to LTM candidate cells (which may be non-serving cells, e.g., candidate cells) is not provided in the current 3GPP specification. Furthermore, the power ramping procedure for PRACH transmission controlled by a PDCCH order formatted as DCI is not incorporated in the current specification. In addition, the current 3GPP specification does not capture PRACH transmissions, and responses (e.g., RAR responses) are not provided to the UE by the RAN node (e.g., gNB).

[0056] Furthermore, current working group agreements relating to the current 3GPP specifications now define the necessary practices in the present situation where it is not necessary to configure RA responses (RARs) for one or more RAN nodes (e.g., one or more gNBs) in a communication network. Traditionally, when a RAN node (e.g., a gNB) issues a PDCCH order, triggering the UE to send an RA preamble back to the RAN node, the RAN node would acknowledge receipt of the RA preamble by sending a RAR to the UE.

[0057] However, according to one or more workinggroup agreements relating to the current 3GPP specification regarding RACH by PDCCH order, if RAR reception is not configured (for example, a gNB is not required to send an RAR to the UE in response to receiving a RACH preamble from the UE), the UE is not permitted to perform autonomous retransmission of PRACH, regardless of the PreambleTransMax configuration. Furthermore, whether or not the terminal performs power rampping is determined by the PDCCH order. If the UE performs power rampping, it can explicitly indicate in the PDCCH order whether the PRACH is the initial transmit or a retransmit and set the power ramping value based on the RA preamble power ramping counter value associated with transmit / retransmit. However, if the terminal does not perform power ramping, the transmit power should be determined by the open-loop power control protocol.

[0058] Therefore, based on the working group agreement related to the current 3GPP specification, when RAR reception is not configured, the UE is explicitly informed whether the PDCCH order is the initial transmit or a retransmit. The UE can use the retransmit instruction to determine whether power rampping should be applied for a PRACH transmit in the current order. If the current power rampping procedure is followed, the power rampping counter is incremented for subsequent retransmissions of the PRACH preamble, provided the target DL RS does not change. Ideally, the UE increments the power ramping counter. However, due to the agreement that autonomous retransmissions by the UE are not permitted, retransmissions are always triggered by the network (e.g., indicated by the PRACH transmit index in the new PDCCH order).

[0059] The current 3GPP specification and the aforementioned working group agreement present several potential problems. In the first scenario, if the UE misses the initial transmission of a PDCCH order (e.g., the PDCCH order may not be received and / or decoded), and the UE receives a subsequent PDCCH order indicating a retransmission of PRACH, it is unclear how the UE can determine the correct power ramping value (e.g., the UE may not be able to determine what the correct RA preamble power ramping counter value should be for indexing the power ramping value).

[0060] In the second scenario, the UE may be unable to determine whether it missed at least one DCI that triggered at least one retransmission of RACH by the PDCCH order after it received the initial PDCCH order, or after it received at least one retransmission instruction after its initial PRACH transmission (i.e., the UE may have missed a retransmission trigger between retransmissions).

[0061] In a third scenario, after receiving a PDCCH order indicating a first DL RS (e.g., as indicated via the first DL RS index and / or SSB index associated with the PDCCH order), the UE receives a subsequent PDCCH order for a PRACH transmission to a new second target DL RS (e.g., the target changes from the current DL RS to another DL RS), and the UE missed the initial transmission for the second DL RS (e.g., did not receive it). In this case, the UE may not know how to determine the correct RA preamble power ramping counter value. Furthermore, the question arises as to how to handle the PREAMBLE_POWER_RAMPING_COUNTER if the UE has already reached the maximum allowable retransmission and / or if the UE may have missed the maximum allowable power ramping step.

[0062] In the fourth scenario, if a PDCCH order is sent to the UE for the reacquisition of a TA for the same serving cell due to a TA invalidation, it is unclear to the UE whether a PDCCH order is sent for the retransmission of a RACH with a higher RA preamble power ramping counter value.

[0063] To address these and other issues, embodiments of the present disclosure are configured to provide PRACH transmission with an improved PDCCH order in LTM.

[0064] In various embodiments, if the UE receives a PDCCH order for a PRACH transmission to at least one LTM candidate cell, and the PDCCH order indicates a retransmission (e.g., associated with) for a target DL RS (e.g., indicated by the DL RS and / or SSB index provided in the PDCCH order) for which the UE has not performed the initial PRACH transmission, the UE should consider that indication to be the initial PRACH transmission from a power ramping perspective. Once the UE determines that the PRACH transmission is the initial transmission, it does not apply power ramping to the PRACH transmission. For example, in various embodiments, the UE sets the RA preamble power ramping counter (e.g., PREAMBLE_POWER_RAMPING_COUNTER) to an initial value (e.g., an initial RA preamble power ramping counter value of 1) to indicate that power ramping is not applied. Thus, the UE may apply power ramping to any subsequent retransmissions for a PRACH preamble having the same target DL RS. Therefore, when a UE receives a PDCCH order, the UE will only apply power ramping (e.g., increment the RA preamble power ramping counter value) if it had performed a PRACH transmission to the same cell (e.g., a serving cell) prior to receiving the PDCCH order.

[0065] In various embodiments, a maximum value for the RA preamble power ramping counter may be defined. This parameter (e.g., "RA preamble power ramping counter maximum value") may be configured by the network (e.g., using RRC signaling). In some scenarios, the RA preamble power ramping counter value is incremented when the RA preamble (re)transmit counter for PRACH is incremented. In some embodiments, the UE may maintain either the RA preamble power ramping counter or the (re)transmit counter or both. The RA preamble power ramping counter value may be incremented each time the UE performs a PRACH transmission, and the UE has decided that the RA preamble power ramping counter value has been incremented. Once the maximum value of the RA preamble power ramping counter is reached, the UE does not apply further power ramping to subsequent PRACH transmissions. In some contexts, the counter value may be cell-specific (e.g., cell-specific maximum value). In some embodiments, the RA preamble power ramping counter may have a predefined maximum value N (e.g., N=1, N=2, N=3, etc.).

[0066] In some contexts, the RA preamble power rampping value (or RA preamble power rampping counter value) can have a limited number of possible values. For example, if the PDCCH order indicates the first transmit, the UE may not apply power ramping (e.g., apply RA preamble power ramping counter value = 1). If the PDCCH order indicates a retransmit, the UE may apply power ramping (e.g., apply RA preamble power ramping counter value = 2 or a value indicating that the power will be increased by at least one step). An RA preamble power ramping counter value of 2 may indicate that at least one power ramping step / value will be applied to the PRACH transmit by the PDCCH order. In some contexts, the UE may not apply further power ramping for subsequent transmits. For example, when the PDCCH order indicates the first transmit, the UE may perform a PRACH transmit (by PDCCH order) at the initial transmit power level (e.g., no power ramping). In another example, when a retransmit is indicated, the UE may perform a PRACH transmit at ramped power. In other examples, the UE may ramp the power in only one step, and no further steps are applied for subsequent retransmissions. The power ramping step value (e.g., expressed in dB) may be configurable, and the power ramping step value may vary (e.g., 3 dB, 6 dB, etc.).

[0067] In some embodiments, the RA preamble power ramping counter value may refer to a power ramping value applied for the initial or retransmission. If the PDCCH order indicates the initial transmission (or the UE determines that the PRACH transmission is considered the initial transmission), the UE may determine that the power ramping counter value is set to a value to which no power ramping is applied. If the PDCCH order indicates the initial transmission, the UE may determine that the RA preamble power ramping counter value may be set to a value to which at least one (or at most one) power ramping step is applied / performed.

[0068] In various embodiments, setting the RA preamble power ramping counter value to a predefined initial counter value may indicate that power ramping is not applied to the PRACH transmission. The predefined initial counter value may refer to a value that, when indicated (for example, or applied), prevents power ramping from being performed.

[0069] In some cases, if the PDCCH order indicates (re)transmission, further instructions may be given in the PDCCH order that provide the power ramping value to be applied for the retransmission. For example, the instructions may consist of a bit field (e.g., a DCI data field) which is mapped to a power ramping step value (e.g., 3dB, 6dB) that may be configured by the RRC.

[0070] In various embodiments, if a UE receives a PDCCH order for a PRACH transmission to at least one LTM candidate cell, and the PDCCH order indicates a retransmission for a target DL RS for which the UE has not performed the initial PRACH transmission, the UE should consider the instruction to be a first PRACH retransmission (e.g., regardless of how many PDCCH orders were missed). Once the UE determines that the PRACH transmission is a first retransmission, it applies power rampping to the PRACH transmission, assuming that the PRACH transmission is a first retransmission. For example, in various embodiments, the UE sets an RA preamble power rampping counter (e.g., PREAMBLE_POWER_RAMPING_COUNTER) to a value indicating that power rampping has been applied in accordance with the first retransmission (e.g., a value equal to the initial RA preamble power rampping counter value that has been incremented once (e.g., the transmit power level is increased by one step)). In other words, even if a network element (e.g., gNB) determines that the UE has incrementally increased the power once or multiple times, the UE will only incrementally increase the power according to the value associated with the first PRACH retransmission. Thus, the UE may apply power ramping (e.g., incrementing the RA preamble power ramping counter value) for any subsequent retransmissions for PRACH preambles having the same target DL RS.

[0071] In various embodiments, if the UE receives a first PDCCH order indicating a retransmission to a first target DL RS (for example, as indicated by a first DL RS index and / or a first SSB index associated with the first PDCCH order), if the UE determines that it has performed at least one or more PRACH transmissions associated with the first target DL RS (for example, the initial transmission or one or more retransmissions), and if the UE determines that it has received a second PDCCH order indicating a retransmission associated with a second target DL RS (for example, as indicated by a second DL RS index and / or a second SSB index associated with the second PDCCH order), where the second PDCCH order is associated with the same LTM candidate cell as the first PDCCH order, the UE sets the RA preamble power ramping counter value to the most recent value associated with at least one or more PRACH transmissions associated with the first target DL RS. Therefore, the UE may apply power ramping (e.g., incrementing the RA preamble power ramping counter value) for any subsequent retransmissions for a PRACH preamble that has the same target DL RS (e.g., a second target DL RS).

[0072] In various embodiments, if the UE receives a first PDCCH order indicating a retransmission to a first target DL RS (for example, as indicated by a first DL RS index and / or a first SSB index associated with the first PDCCH order), and the UE determines that it has performed at least one or more PRACH transmissions associated with the first target DL RS (for example, the initial transmission or one or more retransmissions), and the UE determines that it has received a second PDCCH order indicating a retransmission associated with a second target DL RS (for example, as indicated by a second DL RS index and / or a second SSB index associated with the second PDCCH order), where the second PDCCH order is associated with the same LTM candidate cell as the first PDCCH order, the UE increments the RA preamble power ramping counter value from the most recent value associated with at least one or more PRACH transmissions associated with the first target DL RS. Therefore, the UE may apply power ramping (e.g., incrementing the RA preamble power ramping counter value) for any subsequent retransmissions for a PRACH preamble that has the same target DL RS (e.g., a second target DL RS).

[0073] In various embodiments, if the UE receives a first PDCCH order indicating a retransmission to a first target DL RS (for example, as indicated by a first DL RS index and / or a first SSB index associated with the first PDCCH order), if the UE determines that it has performed at least one or more PRACH transmissions associated with the first target DL RS (for example, the initial transmission or one or more retransmissions), and if the UE determines that it has received a second PDCCH order indicating a retransmission associated with a second target DL RS (for example, as indicated by a second DL RS index and / or a second SSB index associated with the second PDCCH order), where the second PDCCH order is associated with the same LTM candidate cell as the first PDCCH order, the UE resets the RA preamble power rampping counter (for example, PREAMBLE_POWER_RAMPING_COUNTER) to an initial value (for example, an initial RA preamble power rampping counter value of 1) indicating that power ramping is not applied.

[0074] In one or more embodiments, various UL transmission prioritization rules can determine which type of UL transmission (e.g., PRACH, PUCCH, PUSCH, SRS, etc.) takes precedence when one or more UL transmissions collide (e.g., transmitted to the same gNB during the same and / or overlapping time periods). Thus, there are situations in which the UL transmission prioritization rules and / or UE capabilities (e.g., a UE configured to execute only one UL transmission at a time) may drop (e.g., terminate) one or more UL transmissions in favor of a prioritized UL transmission. In various embodiments, if such a UL prioritization / collision situation occurs and the UE fails to execute a PRACH transmission to an LTM candidate cell during the transmission opportunity, the corresponding RA preamble power rampping counter associated with the LTM candidate cell and / or the same or a different DL RS / SSB may be suspended. In other words, if a UL transmission prioritization / collision situation occurs and the UE is unable to execute the expected PRACH transmission, the RA preamble power rampping counter value is not incremented.

[0075] In addition or alternatively, in one or more embodiments, various UL transmit prioritization rules may instruct that UL transmit power be distributed among one or more concurrently running UL transmits (e.g., PRACH, PUCCH, PUSCH, SRS, etc.) so that the initially allocated UL transmit power is shared among concurrently running UL transmits. In various embodiments, if such UL transmit power distribution occurs and a UE transmits PRACH to an LTM candidate cell with reduced power in a transmit opportunity, the corresponding RA preamble power rampping counter associated with the LTM candidate cell and / or the same or different DL RS / SSB may be interrupted. In other words, if a UL transmit collision occurs involving a PRACH transmit where multiple UL transmits must share the initially allocated transmit power, the PRACH power rampping counter value is not incremented.

[0076] In various embodiments, one or more computing powers associated with the UE can limit the number of active RA preamble power rampping counters that the UE can maintain. In various embodiments, one or more computing powers associated with the UE that determine the maximum number of active RA preamble power rampping counters for an LTM RACH procedure without RAR being configured across all candidate cells and / or DL ​​RS / SSBs can be shown to a communication network (e.g., a 5G / 6G or higher network). In one or more embodiments, if the number of active RA preamble power rampping counters exceeds one or more computing powers of the UE, the UE can terminate the oldest active RA preamble power rampping counter associated with an active RA preamble power rampping counter. As an addition or alternative, in various embodiments, one or more computing powers of the UE related to the maximum number of active RA preamble power rampping counters that the UE can maintain can be shown to a communication network (e.g., a 5G network) for all possible RACH procedures for the current serving cell and / or LTM candidate cell. As an addition or alternative, in various embodiments, one or more computing powers of a UE related to the maximum number of active RA preamble power rampping counters that the UE can maintain may be shown to a communication network (e.g., a 5G network) for all possible LTM candidate cells for both PDCCH order RACH options (e.g., RACH with RAR configured in PDCCH order or RACH with RAR configured in PDCCH order).

[0077] In various embodiments, the UE may be configured to maintain the most recent RA preamble power ramping counter value associated with a particular cell and / or DL ​​RS / SSB even after the UE has switched to a new candidate target cell. In various situations, the most recent RA preamble power ramping counter value associated with a particular cell and / or DL ​​RS / SSB used by the UE before cell switching may be used for power ramping for LTM purposes once the UE is serviced by the new candidate target cell. In such situations, using the most recent RA preamble power ramping counter value associated with a particular cell and / or DL ​​RS / SSB used by the UE before cell switching may be useful for dynamic switching purposes.

[0078] In various embodiments, the UE may be configured to maintain the most recent RA preamble power ramping counter value associated with a particular cell and / or DL ​​RS / SSB. For example, if the UE determines that a new target DL RS (e.g., one of the same or a different cell) is indicated by a PDCCH order, the UE may decide to reset the power ramping counter (e.g., or any counter that can be used to determine the power ramping value for a PRACH transmission). In some contexts, the UE may be configured to maintain only one power ramping counter. For example, if only one power ramping counter is maintained and a change in the target DL RS and / or target cell is indicated, the UE may restart the power ramping counter. In other words, the UE does not retain previous counter values. Therefore, when RAR is not configured (e.g., for an LTM candidate cell), a PDCCH order to a new DL RS (e.g., for any cell) is considered a new RACH procedure, and consequently the power ramping counter value / power ramping is reset.

[0079] In various embodiments, RAR is configured such that when the UE acquires the TA of a candidate cell and a PDCCH order is received by the UE for the same candidate cell, the UE may be configured to reset the RA preamble power ramping counter, as it is understood that the PDCCH order is for the purpose of TA reacquisition. Thus, power ramping is not required, and the UE may be configured to perform PRACH transmissions as if they were the first PRACH transmissions.

[0080] In various situations, when RAR is not configured, a TA may be invalid, and conventionally, TA invalidation can only be detected by a network element associated with the serving cell (e.g., a gNB). For example, if a UE receives a PDCCH order for a candidate cell and performs a PRACH transmission, but the candidate cell's network element (e.g., a gNB) transmits a TA to the serving cell, the TA may be invalid, and as described herein, TA invalidation can be detected by the serving cell. In such a case, the serving cell can trigger a TA acquisition for the same candidate cell again using a different PDCCH order. Thus, the serving cell may indicate that the PDCCH order is for TA reacquisition so that the UE does not apply power rampping. In one example, the UE may use the RA preamble power rampping counter value used for the most recent PRACH transmission. In another example, the UE may use the RA preamble power rampping counter value used for the first PRACH transmission. In yet another example, the UE may use the RA preamble power rampping counter value used for the first retransmission of the PRACH transmission. A PDCCH order has a counter for TA acquisitions of a particular cell, and the counter is incremented whenever a PDCCH order is sent for a reacquisition. In other words, a reacquisition of a TA associated with a particular cell can be explicit (e.g., indicated in the PDCCH order) or implicit (e.g., based on the instructions of the initial transmission, the initial transmission is indicated for the same target DL RS where the UE has performed at least one PRACH transmission earlier).

[0081] In various embodiments, the UE receives a PDCCH order for a PRACH transmission to at least one LTM candidate cell, and the PDCCH order indicates a retransmission for a target DL RS from which the UE has previously performed a PRACH transmission (e.g., the first or one or more retransmissions), and the UE modifies the uplink spatial filter for the PRACH transmission (e.g., a spatial domain transmit filter such as a transmit beam), the UE resets the power ramping counter.

[0082] In various embodiments, in a scenario where the UE sends multiple PRACH transmissions to candidate cells having different configurations (e.g., RO and / or RA preamble index with respect to the SSB index), various PRACH transmission prioritization rules may be used by the UE to derive power for a new retransmission (e.g., deriving an RA preamble power ramping counter value). For example, a first priority may be given to a recent PRACH transmission to the same candidate cell where the SSB (or target DL RS), RO, and RA preamble ID are given in PDCCH order along with the retransmission instruction. A second priority may be given to a recent PRACH transmission to the same candidate cell where the SSB (or target DL RS) and RO are given in PDCCH order along with the retransmission instruction. A third priority may be given to a recent PRACH transmission to the same candidate cell where only the SSB (or target DL RS) is given in PDCCH order with the retransmission instruction. A fourth priority may be given to recent PRACH transmissions to the same candidate cell for which none of the SSB (or target DL RS), RO, or RA preamble ID are given in PDCCH order with a retransmission instruction. Thus, in various embodiments, the RA preamble power ramping counter value may be incremented only for PRACH transmissions that meet the criteria of one or more PRACH transmission prioritization rules associated with a predetermined priority level (e.g., a first and / or second priority level).

[0083] In addition or alternatively, in various embodiments, if any of the parameters of the PDCCH order, including candidate cell identification information, SSB (e.g., target DL RS), RO, and / or RA preamble ID, do not match the parameters of a PRACH transmission previously sent by the UE, and the PDCCH order indicates a retransmission, the UE always uses initial power for the PRACH transmission (e.g., RA preamble power ramping counter value = 1, or a value meaning no power ramping is applied).

[0084] Figure 1 shows a communication system 100 configured according to at least some embodiments of this disclosure. However, it should be understood that embodiments are not limited to network configurations illustrated herein or described otherwise below. It should be understood that the elements shown in communication system 100 are intended to represent the main functions provided within the system. Thus, the blocks shown in Figure 1 refer to specific elements in a 5G network that provide the main functions. However, other network elements may be used to implement some or all of the main functions represented. Also, it should be understood that not all functions of a 5G network are shown in Figure 1. Rather, functions that facilitate the explanation of the exemplary embodiments are represented.

[0085] For example, the communication system 100 may be deployed within a radio access architecture. However, the system may also be deployed in other applications, including, for example, within other communication networks, such as LTE Advanced (LTE-A), Universal Mobile Telecommunications System (UMTS) Radio Access Network (UTRAN or E-UTRAN), Wireless Local Area Network (WLAN or Wi-Fi), Worldwide Interoperability for Microwave Access (WiMAX), Bluetooth®, Personal Communication Services (PCS), ZigBee®, Wideband Code Division Multiple Access (WCDMA), systems using ultra-wideband (UWB) technology, sensor networks, mobile ad hoc networks (MANET) and Internet Protocol Multimedia Subsystem (IMS), or any combination thereof. Any access network (AN) eligible to access the 5G core network may be used instead of NG RAN / gNB, such as untrusted non-3GPP access terminated by a Non-3GPP interworking function (N3IWF), trusted non-3GPP access terminated by a trusted Non-3GPP Gateway function (TNGF), or wireless access terminated by a wireless access Gateway function (W-AGF). Furthermore, although described herein in conjunction with the 5G core network, some exemplary embodiments of methods, apparatus, and computer program products may be employed in conjunction with other technologies, such as 5G, 6G, and / or beyond networks.

[0086] UE102 may be configured to be in wireless connectivity with a Radio Access Network (RAN) node, such as a gNB, on one or more communication channels within a cell. The physical link from UE102 to the gNB is called the uplink (UL) or reverse link, and the physical link from the gNB to UE102 is called the downlink (DL) or forward link. It should be understood that the gNB or its functions may be implemented using any node, host, server, or access point (AP), or other entity suitable for such use. Furthermore, UE102 may be configured to be in wireless connectivity with one or more other UEs, for example, via a sidelink channel.

[0087] A communication system typically comprises multiple gNBs, in which case the gNBs may also be configured to communicate with each other via wired or wireless links designed for that purpose. These links may be used for signaling purposes. A gNB is a computing device configured to control the radio resources of the communication system to which the gNB is coupled. A gNB may also be called any other type of interface device, including base stations, access points, or relay stations that can operate in a wireless environment. A gNB comprises or is coupled to one or more transceivers. Connections from the transceivers of the gNB are provided to antenna units that establish a bidirectional wireless link to the UE. Thus, the transceivers of the gNB and the transceivers of the UE may include transmitters and receivers configured to communicate over the channel. While this specification refers to a gNB, this is illustrative and not limiting, and other types of AN nodes may be used instead.

[0088] Accordingly, as shown in the figure, the communication system 100 includes a UE 102 that communicates with one or more AN nodes 104a-n via an air interface or the like. In some embodiments, one or more AN nodes 104a-n are RAN nodes. The UE 102 may be a mobile station, such a mobile station may comprise, for example, a mobile phone, a computer, or any other type of communication device. Accordingly, the terms “User Equipment (UE),” “User Device,” “Computing Device,” or “Apparatus” as used herein are intended to be interpreted broadly to encompass a variety of different types of mobile stations, subscriber stations, or more generally, communication devices, including, for example, a combination of data cards inserted into a laptop or other device.

[0089] UE102 may also refer to portable computing devices, including wireless mobile communication devices operating with or without a Subscriber Identification Module (SIM), including, but not limited to, mobile stations (cell phones), smartphones, personal digital assistants (PDAs), handsets, devices using wireless modems (such as alarm or measuring devices), laptops and / or touchscreen computers, tablets, game consoles, notebooks, and multimedia devices. UE102 may also be a nearly exclusive uplink-only device, an example of which should be understood as a camera or video camera loading images or video clips onto the network. UE102 may also be a device capable of operating in an IoT network, a scenario in which an object is provided with the ability to transfer data over the network without requiring human-to-human or human-to-computer interaction. UE102 (or a Layer 3 relay node in some embodiments) is configured to perform one or more user device functions. UE102 may also be referred to as a subscriber unit, mobile station, remote terminal, access terminal, user terminal, or user device, simply to refer to some name or device.

[0090] In one embodiment, the UE102 consists of a Universal Integrated Circuit Card (UICC) and a Mobile Device (ME). The UICC is the user-dependent portion of the UE and includes at least one Universal Subscriber Identification Module (USIM) and appropriate application software. The USIM securely stores the International Mobile Subscriber Identity (IMSI) number and its associated keys, which are used to identify and authenticate the subscriber and access the network. The ME is the user-independent portion of the UE and includes Terminal Device (TE) functions and various Mobile Terminal (MT) functions.

[0091] AN nodes 104a-n are, exemplarily, part of the RAN of communication system 100. In a 5GS network, AN nodes 104a-n are typically implemented by gNBs. Such an access network may comprise, for example, one or more gNBs (which may also be divided into centralized unit (CU) and distributed unit (DU) parts) and / or multiple base stations, which may include other AN node types such as evolved node B (eNB), node B, base station (BS) and / or N3IWF, or any other type of access node such as a WLAN access point, as well as one or more associated radio network control functions. While base stations and radio network control functions may be logically separate entities, in a given embodiment they may be implemented in the same physical network element, for example, a base station router or a femtocellular access point. As will be understood by those skilled in the art, any various AN nodes and / or access nodes may implement similar operations, functions, etc.

[0092] In some exemplary embodiments, AN nodes 104a-n are operablely coupled to core network functions via NG interfaces, etc. Core network functions may include access and mobility management functions (AMF), session management functions (SMF), representative network functions (NF-X), or any of the core network functions. Core network functions may be elements of the core network (CN) portion of the communication system 100 responsible for one or more associated operations. Additionally or alternatively, AN nodes 104a-n may generate, relay, augment, and / or otherwise manage one or more network cells configured to provide communication services (e.g., providing access to one or more services associated with the core network functions) to one or more UEs 102 located within the operating range of one or more respective network cells.

[0093] According to various embodiments, the LTM serving cell 106 is a network cell associated with an AN node 104a to which the UE 102 is currently connected in order to facilitate communication over a particular network (e.g., a 5G network). The LTM candidate cell 108 is a network cell associated with an AN node 104n to which the UE 102 may potentially switch (e.g., via a handover procedure) when traversing a real-world environment where the UE 102 is associated with one or more network cells related to a particular network (e.g., a 5G network).

[0094] 5G enables the use of multiple-input multiple-output (MIMO) antennas, which are more base stations or nodes than LTE (the so-called small cell concept), and includes macrosites that work in cooperation with smaller stations and use various radio technologies depending on the service needs, use cases, and / or available spectrum. 5G mobile communications support a wide range of use cases and related applications, including video streaming, augmented reality, different methods of data sharing, and various forms of machine-type applications such as (massive) machine-type communications (mMTC), including vehicle safety, different sensors, and real-time control. 5G has multiple radio interfaces, such as below 6 GHz or above 24 GHz (cmWave and mmWave), and can be integrated with existing legacy radio access technologies such as LTE. Integration with LTE can be implemented as a system where macro coverage is provided by LTE and 5G radio interface access comes from small cells by aggregation into LTE. In other words, 5G can support both inter-RAT operation (such as LTE-5G) and inter-RI operation (such as below 6GHz i.e., cmWave, above 6GHz or above 24GHz i.e., cmWave and mmWave).

[0095] Low-latency applications and services in 5G require bringing content closer to the radio, leading to local breakout and multi-access edge computing (MEC). 5G enables analytics and knowledge generation to take place at the data source. This approach requires leveraging resources that may not be continuously connected to the network, such as laptops, smartphones, tablets, and sensors. MEC provides a distributed computing environment for application and service hosting. It also has the ability to store and process content in close proximity to cellular subscribers for faster response times. Edge computing covers a wide range of technologies, including wireless sensor networks, mobile data acquisition, mobile signature analytics, and also collaborative distributed peer-to-peer ad-hoc networking and processing, which can also be classified as local cloud / fog computing and grid / mesh computing, due computing, mobile edge computing, cloudlets, distributed data storage and retrieval, autonomous self-healing networks, remote cloud services, augmented and virtual reality, data caching, the Internet of Things (massive connectivity and / or latency critical), and critical communications (autonomous vehicles, traffic safety, real-time analytics, time-critical control, healthcare applications, etc.).

[0096] Figure 2 shows an example of a device 200 that may be configured to function as, or be implemented by, a network entity such as UE102, UE, AN node 104, AMF, SMF, and / or NF-X. As shown in Figure 2, the device 200 includes, is associated with, or communicates with, a processing circuit 202, a memory device 206, and a communication interface 204. The processing circuit 202 may communicate with the memory device via a bus for passing information between components of the device 200. The memory device 206 may be non-temporary and may include, for example, one or more volatile and / or non-volatile memories. In other words, for example, the memory device 206 may be an electronic storage device (e.g., a computer-readable storage medium) having gates configured to store data (e.g., bits) that may be retrieved by a machine (e.g., a computing device such as a processing circuit). The memory device 206 may be configured to store information, data, content, applications, instructions, etc., to enable the device to perform various functions according to exemplary embodiments of the present disclosure. For example, the memory device 206 may be configured to buffer input data for processing by the processing circuit 202. Alternatively, the memory device 206 may be configured to store instructions for execution by the processing circuit 202.

[0097] In some embodiments, the device 200 may be embodied in various computing devices as described above. However, in some embodiments, the device may be embodied as a chip or chipset. In other words, the device may comprise one or more physical packages (e.g., a chip) including materials, components, and / or wires on a structural assembly (e.g., a baseboard). The structural assembly may provide physical strength, size preservation, and / or limitations on the electrical interaction of component circuits contained thereon. Thus, the device may, in some cases, be configured to implement embodiments on a single chip or as a single "system on a chip". Thus, in some cases, the chip or chipset may constitute means for performing one or more operations to provide the functions described herein.

[0098] The processing circuit 202 can be embodied in several different ways. For example, the processing circuit 202 may be embodied as one or more of various hardware processing means, such as a coprocessor, a microprocessor, a controller, a digital signal processor (DSP), a processing element with or without an associated DSP, or various other circuits, including integrated circuits such as ASICs (Application-Specific Integrated Circuits), FPGAs (Field-Programmable Gate Arrays), microcontroller units (MCUs), hardware accelerators, and dedicated computer chips. Thus, in some embodiments, the processing circuit may include one or more processing cores configured to run independently. A multicore processing circuit can enable multi-processing within a single physical package. As an addition or alternative, the processing circuit may include one or more processors configured in tandem via a bus to enable independent execution of instructions, pipelined, and / or multithreaded.

[0099] In exemplary embodiments, the processing circuit 202 may be configured to execute instructions stored in the memory device 206 or otherwise accessible to the processing circuit 202. Alternatively or additionally, the processing circuit may be configured to perform hardcoded functions. Thus, whether configured by hardware or software methods or a combination thereof, the processing circuit may represent, and be configured accordingly, an entity (e.g., physically embodied in the circuit) capable of performing operations according to embodiments of the present disclosure. For example, when the processing circuit is embodied as an ASIC, FPGA, etc., the processing circuit may be hardware specifically configured to perform the operations described herein. Alternatively, as another example, when the processing circuit 202 is embodied as an instruction executor, the instructions may specifically configure the processor to perform the algorithms and / or operations described herein when the instructions are executed. However, in some cases, the processing circuit 202 may be the processor of a particular device (e.g., an image or video processing system) configured to use embodiments of the present disclosure by further configuration of the processing circuit with instructions for performing the algorithms and / or operations described herein. The processing circuit 202 may include, among other things, a clock, an arithmetic logic unit (ALU), and logic gates configured to support the operation of the processing circuit.

[0100] The communication interface 204 may be any means, such as a device or circuit, embodied in either hardware or a combination of hardware and software, configured to receive and / or transmit data to and from any other device (e.g., a specific UE102, UE, etc.) or module communicating with the network and / or equipment. In this regard, the communication interface 204 may include, for example, an antenna (or a number of antennas) and supporting hardware and / or software to enable communication with a wireless communication network. Furthermore, the communication interface 204 may embody and / or integrate one or more RF and / or wireless transceivers, each including a transmitter for transmitting signals and a receiver for receiving signals. One or more RF and / or wireless transceivers may be configured to facilitate communication in 4G / LTE networks, 5G networks, etc. Furthermore, one or more RF and / or wireless transceivers may be configured to facilitate communication on various respective communication networks. One or more RF and / or wireless transceivers receive signals or data and / or transmit signals and / or data. In various embodiments, the processing circuit 202 can control the antenna and / or one or more RF and / or wireless transceivers to receive, transmit, broadcast, or transmit signals and / or data. In addition, or alternatively, the communication interface 204 may include circuitry for interacting with the antenna and / or one or more RF and / or wireless transceivers to cause the transmission of signals through the antenna or to process the reception of signals received through the antenna. In addition, or alternatively, in some environments, the communication interface 204 may support wired communication. For example, the communication interface may include a communication modem and / or other hardware / software to support communication via cable, digital subscriber line (DSL), universal serial bus (USB) or other mechanism.

[0101] Figures 3A and 3B are flowcharts of Method 300 for providing PRACH transmission in an improved order in LTM, according to one or more exemplary embodiments of the present disclosure. Method 300 may be implemented, for example, by one or more components of a device 200. In various embodiments, the device 200 may be embodied by a networking element (e.g., a gNB). In various other embodiments, the device 200 may be embodied by a UE 102. As an addition or alternative, the device 200 may be embodied by any other particular computing device associated with a particular communication network (e.g., a smartphone, laptop, tablet computer, networking device, etc.). The device 200 may be configured to perform Method 300, and it will be understood that the components of the device 200 are again provided as examples, not as an limitation. Thus, the device 200 includes means such as a processing circuit 202, at least one processor, a communication interface 204, and at least one memory device 206, configured to perform various operations associated with Method 300.

[0102] Method 300 is PRACH transmit power level (P PRACH The power ramping model is determined by the UE and associated with a power ramping model used to perform a PRACH transmission for the first cell (e.g., LTM serving cell 106 or LTM candidate cell 108) in response to receiving one or more PDCCH orders from the first cell. For the purpose of simplifying the exemplary embodiments shown by Method 300, several conditional parameters related to the power ramping model are predefined. For example, RAR is not set for the UE and / or network elements associated with this exemplary embodiment, the UE is given maximum power (maxPower), and the first cell is given ss-PBCH-BlockPower, RA preamble receive target power (Target P ), and RA preamble power ramping step (Step P ) is given, RA preamble power ramping counter (Count P The value of ) is initialized to 1. The power ramping model calculates the path loss (PL) for a specific DL RS associated with each SSB. P ), and also involves deriving the updated RA preamble receive target power (P1). PRACH To derive this, a comparison function constructed to derive the minimum value from a set of values ​​(for example, min(x,y)) is min(maxPower,(P1+PL P It will be adopted to determine the following.

[0103] Method 300 begins with Operation 302, in which the device 200 is configured to receive a first PDCCH order associated with a first cell, the first PDCCH order indicating a first DL RS associated with a first SSB, and the first PDCCH order includes a PRACH transmit index value indicating that the PRACH transmit is the first transmit.

[0104] In Operation 304, the device 200 is configured to run a power ramping model based in part on a first PDCCH order and a predefined RA preamble power ramping counter value. For example, the device 200 calculates the path loss (PL) for the first DL RS associated with the first SSB by the following formula: P ) can be derived.

number

number

[0105] P PRACH This is determined as follows:

number

[0106] In operation 306, the device 200 is configured to receive a second PDCCH order associated with a first cell, the second PDCCH order indicating a first DL RS, and the second PDCCH order includes a PRACH transmission index value indicating that the PRACH transmission is a retransmission.

[0107] In operation 308, the device 200 is configured to increment the RA preamble power ramping counter value to a predetermined value associated with the first iterative transmission and to execute a power ramping model partially based on the first PDCCH order and the RA preamble power ramping value. For example, Count P , Count P =Count PIt can be incremented to +1. Thus, the device 200 calculates the path loss (PL) for the first DL RS associated with the first SSB by equation (1). P ) can be derived, and the updated RA preamble receive target power (P1) is Count P The new value of PRACH can be derived by inputting it into equation (2), and the PRACH transmit power level P PRACH This can be determined by equation (3).

[0108] In operation 310, the device 200 is configured to receive a third PDCCH order associated with a first cell, the third PDCCH order indicating a second DL RS, and the third PDCCH order having a PRACH transmit index value indicating that the PRACH transmit is a retransmission. In various embodiments, there are three main alternative schemes that the power ramping model can be configured to perform when the UE makes a first determination that it has received multiple PDCCH orders indicating a retransmission for one or more DL RSs (e.g., indicated by DL RS indices and / or SSB indices associated with the multiple PDCCH orders), and the multiple PDCCH orders are associated with the same cell. As shown in Figures 3A and 3B, the three main alternative schemes (e.g., ALT.A to ALT.C are associated with operations 312, 314, and 316, respectively) apply power ramping to the respective PRACH transmit power level P PRACH It can be used to determine

[0109] In alternative option 312, the device 200 is configured to set the RA preamble power ramping counter value to the latest value associated with the PRACH transmission associated with the first DL RS, and to execute a power ramping model based on a third PDCCH order so that power ramping is not performed. For example, Count P , Count P =Count PThis can be maintained. Therefore, the device 200 calculates the path loss (PL) for the first DL RS associated with the first SSB. P ) can be derived by equation (1), and the updated RA preamble receive target power (P1) is Count P The value of can be derived by inputting it into equation (2), and the PRACH transmit power level P PRACH This can be determined by equation (3). Thus, the UE may apply power ramping (e.g., incrementing the RA preamble power ramping counter value) for any subsequent retransmissions for a PRACH preamble that has the same target DL RS (e.g., a second target DL RS).

[0110] In alternative option 314, the device 200 is configured to run a power ramping model based on a third PDCCH order, incrementing the RA preamble power ramping counter value from the latest value associated with the PRACH transmission associated with the first DL RS associated with the first SSB, and performing power ramping as appropriate. For example, Count P , Count P =Count P It can be incremented to +1. Thus, the device 200 calculates the path loss (PL) for the first DL RS associated with the first SSB by equation (1). P ) can be derived, and the updated RA preamble receive target power (P1) is Count P The new value of PRACH can be derived by inputting it into equation (2), and the PRACH transmit power level P PRACH This can be determined by equation (3).

[0111] In alternative option 316, the device 200 is configured to reset the RA preamble power ramping counter value to a predetermined initial counter value and to execute a power ramping model based on a third PDCCH order so that power ramping is not performed. For example, CountP , Count P It can be reset to =1. Thus, the device 200 calculates the path loss (PL) for the first DL RS associated with the first SSB by equation (1). P ) can be derived, and the updated RA preamble receive target power (P1) is Count P The new value of PRACH can be derived by inputting it into equation (2), and the PRACH transmit power level P PRACH This can be determined by equation (3).

[0112] Figure 4 shows a flowchart illustrating a method 400 for PRACH transmission in an improved order for a user device (UE), according to one or more exemplary embodiments of the present disclosure. The method 400 may be implemented, for example, by one or more components of a device 200. In various embodiments, the device 200 may be embodied by a networking element (e.g., a gNB). In various other embodiments, the device 200 may be embodied by a UE 102. As an addition or alternative, the device 200 may be embodied by any other particular computing device associated with a particular communication network (e.g., a smartphone, laptop, tablet computer, networking device, etc.). The device 200 may be configured to perform the method 400, and it will be understood that the components of the device 200 are again provided as examples, not as an limitation. Thus, the device 200 includes means such as a processing circuit 202, at least one processor, a communication interface 204, and at least one memory device 206, configured to perform the various operations associated with the method 400.

[0113] Method 400 begins with Operation 402, in which the device 200 is configured to receive a first PDCCH order from a network element to initiate a PRACH transmission to at least one cell.

[0114] In Operation 404, the device 200 is configured to decode a PRACH transmit index value associated with a first PDCCH order, the PRACH transmit index value indicating whether the PRACH transmit is the first transmit or a retransmit, and the PRACH transmit index value is associated with DL RS, which is indicated by the downlink (DL) reference signal (RS) index associated with the first PDCCH order.

[0115] In operation 406, the device 200 is configured to determine the RA preamble power ramping counter value based in part on at least one of the PRACH transmit index value or the target DL RS.

[0116] In operation 408, the device 200 is configured to transmit a PRACH transmit to at least one cell, partly based on a PRACH transmit power level, the PRACH transmit power level being determined partly based on an RA preamble power ramping counter value.

[0117] Figure 5 is a flowchart illustrating a method 500 for PRACH transmission in an improved order for network elements, according to one or more exemplary embodiments of the present disclosure. The method 500 may be implemented, for example, by one or more components of a device 200. In various embodiments, the device 200 may be embodied by a networking element (e.g., a gNB). In various other embodiments, the device 200 may be embodied by a UE 102. As an addition or alternative, the device 200 may be embodied by any other particular computing device associated with a particular communication network (e.g., a smartphone, laptop, tablet computer, networking device, etc.). The device 200 may be configured to perform the method 500, and it will be understood that the components of the device 200 are again provided as examples, not as an limitation. Thus, the device 200 includes means such as a processing circuit 202, at least one processor, a communication interface 204, and at least one memory device 206, configured to perform various operations associated with the method 500.

[0118] Method 500 begins with Operation 502, in which the device 200 is configured to generate a PDCCH order configured to cause the UE to initiate a PRACH transmission to at least one cell (e.g., LTM candidate cell 108), the PDCCH order being configured to instruct the UE to obtain a timing advance value associated with at least one cell.

[0119] In operation 504, the device 200 is configured to determine the target DL RS.

[0120] In operation 506, the device 200 is configured to encode the DL RS index associated with the PDCCH order, based in part on the DL RS.

[0121] In operation 508, the device 200 is configured to encode the PRACH transmit index using a PRACH transmit index value that indicates whether the PRACH transmit is the first transmit or a retransmit, and the PRACH transmit index value is associated with the DL RS.

[0122] In operation 510, the device 200 is configured to send a PDCCH order to the UE.

[0123] As described herein, exemplary embodiments of the present disclosure can provide improved PDCCH-ordered PRACH transmission in LTM. Embodiments of the present disclosure provide several technical benefits, including reducing transmission latency, transmission overhead, and mitigating network service downtime commonly associated with conventional L3-based mobility management. In this regard, various embodiments provide techniques for enhancing PDCCH-ordered PRACH transmission for multiple TA operations (e.g., intra-cell and / or inter-cell TA operations) that may be maintained for a serving cell at multiple TA values. This process, known as early TA acquisition, allows embodiments to acquire the TA value of at least one candidate network cell (e.g., a target LTM candidate cell) before executing a cell switching command configured to switch the UE from the current source cell (e.g., a serving cell) associated with the UE to a candidate network cell. Furthermore, the embodiment provides the technical benefit of reducing excessive power consumption by one or more UEs by managing the power ramping performance associated with transmitting PRACH transmissions to one or more cells associated with a communication network (e.g., a 5G, 6G (or beyond) type network) by one or more UEs.

[0124] The exemplary embodiments described herein are not limited to systems given as examples, such as 5G systems, and those skilled in the art should understand that this solution may be applied to other communication systems. In addition, although this specification describes the method in the context of a UE performing the method, the method may be performed by other types of devices, such as devices associated with and / or communicating with a UE, as in other exemplary embodiments.

[0125] Furthermore, the various implementations of the techniques described herein may be implemented in digital electronic circuits, or in computer hardware, firmware, software, or a combination thereof. Embodiments may be implemented as computer program products (e.g., computer programs specifically embodied in information carriers (e.g., machine-readable storage devices or propagating signals)) to control execution or operation by data processing devices (e.g., programmable processors, computers, or multiple computers). Implementations may also be provided on computer-readable media or computer-readable storage media, which may be non-temporary media. Implementations of the various techniques may also include implementations provided via temporary signals or media, and / or implementations of programs and / or software that are downloadable via the Internet or other networks, wired networks and / or wireless networks.

[0126] A computer program may be in source code format, object code format, or some intermediate format, and may be stored on any kind of carrier, distribution medium, or computer-readable medium, which may be any entity or device capable of carrying the program. Such carriers include, for example, recording media, computer memory, read-only memory, photoelectric and / or electrical carrier signals, telecommunication signals, and software distribution packages. Depending on the processing power required, a computer program may run on a single electronic digital computer or be distributed across several computers.

[0127] Computer programs, such as those described herein, can be written in any form of programming language, including compiled or interpreted languages, and can be deployed as standalone programs or in any form, including modules, components, subroutines, or other units or parts suitable for use in a computing environment. Computer programs can be deployed to run on one computer at one site, on multiple computers, or distributed across multiple sites and interconnected by a communication network.

[0128] The method steps may be performed by one or more programmable processors that execute a computer program or a portion of a computer program to perform a function by acting on input data and generating an output. The method steps may also be performed by a dedicated logic circuit, such as an FPGA (Field Programmable Gate Array) or ASIC (Application-Specific Integrated Circuit), and the device may be implemented as a dedicated logic circuit, such as an FPGA or ASIC.

[0129] It will be understood that each block of a flowchart and combinations of blocks of a flowchart can be implemented by various means, such as hardware, firmware, processors, circuits, and / or other communication devices associated with the execution of software including one or more computer program instructions. For example, one or more of the procedures described herein can be embodied by computer program instructions. In this regard, computer program instructions that embody the procedures described herein may be stored, for example, in a memory device 206 of an apparatus 200 or other apparatus employing embodiments of the present disclosure and executed by a processing circuit 202. As will be understood, any such computer program instructions can be loaded onto a computer or other programmable device (e.g., hardware) to generate a machine such that the resulting computer or other programmable device implements the functions specified in the blocks of the flowchart. These computer program instructions can also be stored in computer-readable memory that can instruct the computer or other programmable device to function in a particular way, and as a result, the instructions stored in computer-readable memory generate a product whose execution implements the functions specified in the blocks of the flowchart. Computer program instructions can also be loaded onto a computer or other programmable device to perform a series of actions on the computer or other programmable device, thereby generating a computer implementation process that provides actions to implement the functions specified in the flowchart blocks, which are then executed on the computer or other programmable device.

[0130] Therefore, the blocks in a flowchart support combinations of means for performing a specified function and combinations of actions for performing a specified function. It will also be understood that one or more blocks in a flowchart, and combinations of blocks in a flowchart, may be implemented by a dedicated hardware-based computer system that performs a specified function, or by a combination of dedicated hardware and computer instructions.

[0131] In some embodiments, some of the operations described herein may be modified or further amplified. Furthermore, in some embodiments, additional optional operations may be included. Modifications, additions, or amplifications to the operations described herein may be made in any order and in any combination.

[0132] Many modifications and other embodiments of the Disclosure described herein will be apparent to those skilled in the art who are interested in the teachings presented in the foregoing description and the accompanying drawings. Therefore, it should be understood that the Disclosure is not limited to the specific embodiments disclosed, and modifications and other embodiments are intended to be included within the scope of the appended claims. Certain terms are used herein, but they are used in a general and descriptive sense only and are not intended to be limiting.

Claims

1. At least one processor, A device comprising at least one memory containing computer program code, wherein the at least one memory and the computer program code are used by the at least one processor to process the device at least, The steps include receiving a first physical downlink control channel (PDCCH) order from a network element in order to initiate physical random access channel (PRACH) transmission to at least one cell, A step of decoding a PRACH transmit index value associated with the first PDCCH order, wherein the PRACH transmit index value indicates whether the PRACH transmit is the first transmit or a retransmit, and the PRACH transmit index value is associated with a target DL RS indicated by a downlink (DL) reference signal (RS) index associated with the first PDCCH order, The steps include determining a random access (RA) preamble power ramping counter value based in part on at least one of the PRACH transmission index value or the target DL RS, An apparatus configured to perform the steps of transmitting a PRACH transmission to at least one cell, based in part on a PRACH transmission power level, wherein the PRACH transmission power level is determined in part on the RA preamble power ramping counter value, and the PRACH transmission includes at least an RA preamble.

2. The aforementioned computer program code is provided to the device at least as follows: In response to the determination that the PRACH transmit index value associated with the first PDCCH order indicates a retransmission associated with the first target DL RS, In response to the determination that the device has not performed the first PRACH transmission associated with the first target DL RS, The apparatus according to claim 1, further configured to perform the step of setting the RA preamble power ramping counter value to a predetermined initial counter value.

3. The aforementioned computer program code is provided to the device at least as follows: In response to the determination that the PRACH transmit index value associated with the first PDCCH order indicates a retransmission associated with the first target DL RS, In response to the determination that the device has not performed the first PRACH transmission associated with the first target DL RS, The apparatus according to claim 1, further configured to perform a step of incrementing the RA preamble power ramping counter value to a predetermined value associated with the first retransmission.

4. The aforementioned computer program code is provided to the device at least as follows: In response to the determination that the PRACH transmission index value associated with the first PDCCH order indicates a retransmission associated with the first target DL RS, In response to the device determining that it has performed at least one PRACH transmission associated with the first target DL RS, A second PDCCH order indicating a retransmission associated with a second target DL RS, in response to receiving the second PDCCH order associated with the same LTM candidate cell, The apparatus according to claim 1, further configured to perform the step of setting the RA preamble power ramping counter value to the latest value associated with the at least one PRACH transmission associated with the first target DL RS.

5. The aforementioned computer program code is provided to the device at least as follows: In response to the determination that the PRACH transmission index value associated with the first PDCCH order indicates a retransmission associated with the first target DL RS, In response to the device determining that it has performed at least one PRACH transmission associated with the first target DL RS, A second PDCCH order indicating a retransmission associated with a second target DL RS, in response to the receipt of the second PDCCH order associated with the same cell, The apparatus according to claim 1, further configured to perform the step of incrementing the RA preamble power ramping counter value from the latest value associated with the at least one PRACH transmission associated with the first target DL RS.

6. The aforementioned computer program code is provided to the device at least as follows: In response to the determination that the PRACH transmission index value associated with the first PDCCH order indicates a retransmission associated with the first target DL RS, In response to the device determining that it has performed at least one PRACH transmission associated with the first target DL RS, A second PDCCH order indicating a retransmission associated with a second target DL RS, in response to the receipt of the second PDCCH order associated with the same cell, The apparatus according to claim 1, further configured to perform the step of resetting the RA preamble power ramping counter value.

7. The apparatus according to claim 1, wherein the first PDCCH order is comprised of a DCI format associated with one or more downlink control information (DCI) data fields, and the one or more DCI data fields comprise data associated with at least one of the following: an instruction for LTM candidate cell identification information, the DL RS index, RACH opportunity, RA preamble index, PRACH transmission index, or RA response (RAR) configuration instruction.

8. The apparatus according to claim 1, characterized in that the first PDCCH order indicates that RAR is not set.

9. The apparatus according to claim 1, wherein the number of active RA preamble power rampping counters that the apparatus can maintain is determined by one or more computing powers associated with the apparatus, and the active RA preamble power rampping counters are associated with one or more PDCCH orders received by the apparatus.

10. The aforementioned computer program code is provided to the device at least as follows: The steps include determining whether the number of active RA preamble power ramping counters associated with the device exceeds the one or more computing powers associated with the device, In response to a determination that the number of active RA preamble power ramping counters associated with the device exceeds the one or more computing capabilities of the device, The apparatus according to claim 9, further configured to perform the step of terminating the oldest active RA preamble power rampping counter associated with the active RA preamble power rampping counter.

11. The apparatus according to claim 1, wherein the first PDCCH order is configured to instruct the apparatus to obtain a timing advance value associated with the at least one cell, and the timing advance value is used in a cell switching procedure configured to switch the apparatus to the at least one cell.

12. The apparatus according to claim 1, characterized in that the PRACH transmit power level is determined in part based on inputting the RA preamble power ramping counter value into the power ramping model.

13. At least one processor, A device comprising at least one memory containing computer program code, wherein the at least one memory and the computer program code are used by the at least one processor to process the device at least, A step of causing a user device (UE) to perform a step of generating a physical downlink control channel (PDCCH) order configured to cause the UE to initiate physical random access channel (PRACH) transmission to at least one cell, wherein the PDCCH order is configured to instruct the UE to obtain a timing advance value associated with the at least one cell, The computer program code configured to generate the PDCCH order is: The steps include determining the target downlink (DL) reference signal (RS), The steps include encoding a DL RS index associated with the PDCCH order based in part on the DL RS, A step of encoding the PRACH transmission index with a PRACH transmission index value indicating whether the PRACH transmission is the first transmission or a retransmission, wherein the PRACH transmission index value is associated with the DL RS, A device characterized by including an instruction configured to perform the step of causing the UE to transmit the PDCCH order.

14. The aforementioned computer program code is provided to the device at least as follows: In response to the step of causing the UE to send the PDCCH order, The apparatus according to claim 13, characterized in that it is configured to perform the step of receiving one or more PRACH transmissions from the UE, wherein each of the one or more PRACH transmissions comprises at least its own random access (RA) preamble.

15. A computer implementation method, The user device receives a first physical downlink control channel (PDCCH) order in order to initiate physical random access channel (PRACH) transmission from a network element to at least one cell, A step of decoding a PRACH transmit index value associated with the first PDCCH order using the user device, wherein the PRACH transmit index value indicates whether the PRACH transmit is the first transmit or a retransmit, and the PRACH transmit index value is associated with a target DL RS indicated by a downlink (DL) reference signal (RS) index associated with the first PDCCH order, The steps include determining a random access (RA) preamble power ramping counter value based in part on at least one of the PRACH transmit index value or the target DL RS using the user equipment, A computer implementation method characterized by comprising the step of transmitting the PRACH transmission to the at least one cell by the user device, wherein the PRACH transmission power level is determined in part based on the RA preamble power ramping counter value.

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