UE output power requirements for selecting the number of PRACH repetitions

Abstract

1. A method comprising: measuring, at a user equipment, a received power of a reference signal; determining, at the user equipment, based on the measurement of the received power, that a physical random access channel will be transmitted using multiplexed transmission; determining, at the user equipment, a transmit power of the physical random access channel; determining, at the user equipment, a power threshold; and at least one of determining that the determined transmit power is less than the power threshold and sending, at the user equipment, the physical random access channel without multiplexed transmission of the physical random access channel; or determining that the determined transmit power is greater than the power threshold and sending, at the user equipment, the physical random access channel using multiplexed transmission of the physical random access channel.

Description

[Technical Field]

[0001] The exemplary, non-limiting embodiments relate generally to physical random access channel transmissions, and more particularly to physical random access channel repetitions. [Background technology]

[0002] 5G NR supports two contention-based random access (CBRA) procedures: 4-step RACH (Rel-15) and 2-step RACH (Rel-16). Summary of the Invention [Means for solving the problem]

[0003] The following summary is intended to be an example only and is not intended to limit the scope of the claims.

[0004] According to one aspect, a method for transmitting a PRACH signal includes measuring a received power of a reference signal at a user equipment, determining at the user equipment based on the measured received power that the PRACH signal will be transmitted using multiplexed transmission, determining at the user equipment a transmit power of the PRACH signal, and determining at the user equipment a power threshold. determining that the determined transmission power is less than a power threshold and transmitting the physical random access channel by the user equipment without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel at the user equipment using multiplexed transmission of the physical random access channel; with at least one of An example method is provided, including:

[0005] According to another aspect, at least one processor and at least one non-transitory memory, when executed on the at least one processor, measuring with an apparatus the received power of a reference signal; determining at the apparatus based on the received power measurement that the physical random access channel will be transmitted using multiplexed transmission; determining, by the device, a transmit power of a physical random access channel; determining a power threshold at the device; determining that the determined transmission power is less than a power threshold, and transmitting the physical random access channel with the device without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel by the device using multiplexed transmission of the physical random access channel; with at least one of at least one non-transitory memory storing instructions that cause the device to perform the An example of an apparatus is provided, comprising:

[0006] According to another aspect, an example embodiment provides a non-transitory program storage device readable by a device tangibly embodying a program of device-executable instructions for performing operations, the operations comprising: measuring with an apparatus the received power of a reference signal; determining at the apparatus based on the received power measurement that the physical random access channel will be transmitted using multiplexed transmission; determining, by the device, a transmit power of a physical random access channel; determining a power threshold at the device; determining that the determined transmission power is less than a power threshold, and transmitting the physical random access channel with the device without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel by the device using multiplexed transmission of the physical random access channel; with at least one of Includes.

[0007] According to another aspect, a method for transmitting a PRACH signal includes: means for measuring a received power of a reference signal at the apparatus; means for determining, at the apparatus, based on the measurement of the received power, that a PRACH signal will be transmitted using multiplexed transmission; means for determining, at the apparatus, a transmit power of the PRACH signal; and means for determining, at the apparatus, a power threshold. determining that the determined transmission power is less than a power threshold, and transmitting the physical random access channel with the device without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel by the device using multiplexed transmission of the physical random access channel; and means for performing at least one of An example of an apparatus is provided, comprising:

[0008] According to another aspect, a circuit device configured to measure, in an apparatus, a received power of a reference signal; a circuit device configured to determine, in an apparatus, based on the measurement of the received power, that a physical random access channel will be transmitted using multiplexed transmission; a circuit device configured to determine, in an apparatus, a transmission power of the physical random access channel; and a circuit device configured to determine, in an apparatus, a power threshold. determining that the determined transmission power is less than a power threshold, and transmitting the physical random access channel with the device without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel by the device using multiplexed transmission of the physical random access channel; a circuit device configured for at least one of An example of an apparatus is provided, comprising:

[0009] According to some aspects, the subject matter of the independent claims is provided. Some further aspects are provided in the subject matter of the dependent claims.

[0010] The foregoing aspects and other features are explained in the following description taken in conjunction with the accompanying drawings. [Brief explanation of the drawings]

[0011] [Figure 1] FIG. 1 is a block diagram of one possible non-limiting example system in which example embodiments may be practiced. [Figure 2] FIG. 1 illustrates a four-step RACH procedure. [Figure 3] FIG. 10 illustrates an example of associating SSB-RSRP with the number of PRACH repetitions. [Figure 4] A diagram showing the SSB-RSRP configuration procedure when attempting a second PRACH. [Figure 5] FIG. 1 illustrates an example method. [Figure 6] FIG. 1 illustrates an example method. [Figure 7] FIG. 1 illustrates an example method. [Figure 8] FIG. 1 illustrates an example method. [Figure 9] FIG. 1 illustrates an example method. [Figure 10] FIG. 1 illustrates an example method. [Figure 11] FIG. 1 illustrates an example method. DETAILED DESCRIPTION OF THE INVENTION

[0012] The following abbreviations that may be found in the present specification and / or depicted figures are defined as follows: 3GPP 3rd Generation Partnership Project 5G (5th Generation) 5GC 5G Core Network A-MPR Additional MPR AMF Access and Mobility Management Functions CE Coverage Enhanced CE UE Coverage Enhanced UE CP-OFDM Cyclic Prefix OFDM CRC Cyclic Redundancy Check CU Central Unit DCI Downlink Control Information DCI Format 0_1 ​​UL grant configurable by RRC DFT-s-OFDM Discrete Fourier Transform Spread Orthogonal Frequency Division Multiplexing DU Distributed Unit DWS Dynamic Waveform Switching eNB (or eNodeB) Evolved Node B (e.g., LTE base station) EN-DC E-UTRA-NR dual connectivity A node that provides NR user plane and control plane protocol termination towards en-gNB or En-gNB UEs and acts as a secondary node in the EN-DC E-UTRA Evolved Universal Terrestrial Radio Access, i.e. LTE radio access technology FDD Frequency Division Duplex FDM Frequency Domain Multiplexing FR1 Frequency Range 1 FR2 Frequency Range 2 GC-DCI Group Common DCI gNB (or gNodeB) A base station for 5G / NR, i.e., a node that provides NR user plane and control plane protocol terminations towards UEs and is connected to 5G via the NG interface I / F interface LSB least significant bit LTE Long Term Evolution MAC Media Access Control MCS Modulation and Coding Scheme MIMO Multiple Input Multiple Output MME Mobility Management Entity MPR Maximum Power Reduction MSB Most Significant Bit Msg1 Message 1 ng or NG New Generation ng-eNB or NG-eNB New Generation eNB NR new radio N / W or NW Network OFDM Orthogonal Frequency Division Multiplexing PDCCH Physical Downlink Control Channel PDCP Packet Data Convergence Protocol PDU Protocol Data Unit PHR Power Headroom Report PHY physical layer PRACH Physical Random Access Channel PUSCH Physical Uplink Control Channel QPSK 4 phase shift encoding RAN Radio Access Network RACH Random Access Channel RAPID Random Access Preamble ID RAR Random Access Response RA-RNTI Random Access - Radio Network Temporary Identifier RB, PRB resource block, physical resource block RSRP reference signal received power Rel Release RLC Radio Link Control RNTI Radio Network Temporary Identifier RO rach occasion RRH Remote Radio Head RRC Radio Resource Control RU Wireless Unit Rx Receiver SDAP Service Data Structure Protocol S / P Serial to Parallel SGW Serving Gateway SIB1 System Information Block 1 SMF Session Management Facility SR Schedule Request SS / PBCH Synchronization Signal / Physical Broadcast Channel SSB sync signal block TB Conversion Block TDD time division duplex TEI technology enhancement items TPC Transmission Power Control TS Technical Specifications Tx Transmitter UE User Equipment (e.g., wireless, typically mobile device) UL Uplink UPF User Plane Function WI work item Turning to FIG. 1 , this figure illustrates a block diagram of one possible, non-limiting example, which may be configured to operate according to a cellular communication standard, such as fifth generation (5G), also known as Long Term Evolution (LTE) or New Radio (NR), 5G Advanced (i.e., NR Rel-18 and later), and 6G, all specified by the Third Generation Partnership Project (3GPP). Shown are user equipment (UE) 110, radio access network (RAN) nodes 170, and network elements 190. In the example of FIG. 1 , the user equipment (UE) 110 is in wireless communication with a wireless network 100. The UE is a wireless device that can access the wireless network 100. The UE 110 includes one or more processors 120, one or more memories 125, and one or more transceivers 130 interconnected through one or more buses 127. Each of the one or more transceivers 130 includes a receiver (Rx) 132 and a transmitter (Tx) 133. The one or more buses 127 may be address, data, or control buses and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, optical fiber or other optical communication equipment, and the like. The one or more transceivers 130 are connected to one or more antennas 128. The one or more memories 125 contain computer program code 123. The UE 110 includes a module 140 comprising one or both of portions 140-1 and / or 140-2, which may be implemented in several ways. The module 140 may be implemented in hardware as module 140-1, such as implemented as part of one or more processors 120. The module 140-1 may also be implemented as an integrated circuit or through other hardware, such as a programmable gate array. In another example, the module 140 may be implemented as module 140-2, implemented as computer program code 123 and executed by one or more processors 120.For example, the one or more memories 125 and the computer program code 123 may be configured with the one or more processors 120 to cause the user equipment 110 to perform one or more of the operations as described herein. The UE 110 communicates with the RAN node 170 via a wireless link 111.

[0013] The RAN node 170 in this example is a base station that provides access to the wireless network 100 by wireless devices such as the UE 110. The RAN node 170 may be, for example, a base station for 5G, also known as New Radio (NR). In 5G, the RAN node 170 may be an NG-RAN node, defined as a gNB or ng-eNB. A gNB is a node that provides NR user plane and control plane protocol terminations for UEs and is connected to the 5GC (e.g., network element 190) via an NG interface. An ng-RAN node is a node that provides E-UTRA user plane and control plane protocol terminations for UEs and is connected to the 5GC via an NG interface. An NG-RAN node may also include a central unit (CU) (gNB-CU) 196 and distributed units (DUs) (gNB-DUs), of which DU 195 is shown, and may include multiple gNBs. Note that a DU includes or is coupled to a radio unit (RU) and controls the RU. The gNB-CU is a logical node that hosts the RRC, SDAP, and PDCP protocols of a gNB or the RRC and PDCP protocols of an en-gNB, controlling the operation of one or more gNB-DUs. The gNB-CU terminates the F1 interface connected to the gNB-DU. The F1 interface is indicated by reference numeral 198, which also indicates a link between a remote element of the RAN node 170 and a centralized element of the RAN node 170, such as between the gNB-CU 196 and the gNB-DU 195. The gNB-DU is a logical node that hosts the RLC, MAC, and PHY layers of a gNB or en-gNB, and its operation is partially controlled by the gNB-CU. One gNB-CU supports one or many cells. A cell is supported by only one gNB-DU. The gNB-DU terminates the F1 interface 198 connected to the gNB-CU.It should be noted that while the DU 195 is considered to include the transceiver 160, for example as part of an RU, some examples of this may have the transceiver 160 as part of a separate RU, for example controlled by and connected to the DU 195. The RAN node 170 may also be an eNB (Evolved Node B) base station for LTE (Long Term Evolution), or any other suitable base station or node.

[0014] The RAN node 170 includes one or more processors 152, one or more memories 155, one or more network interfaces (N / WI / F) 161, and one or more transceivers 160 interconnected through one or more buses 157. Each of the one or more transceivers 160 includes a receiver Rx 162 and a transmitter Tx 163. The one or more transceivers 160 are connected to one or more antennas 158. The one or more memories 155 include computer program code 153. The CU 196 may include the processor 152, the memory 155, and the network interface 161. Note that the DU 195 may also include its own memory and processor and / or other hardware, which are not shown.

[0015] The RAN node 170 includes a module 150 comprising one or both of portions 150-1 and / or 150-2, which may be implemented in several manners. The module 150 may be implemented in hardware as module 150-1, such as implemented as part of one or more processors 152. The module 150-1 may also be implemented as an integrated circuit or through other hardware, such as a programmable gate array. In another example, the module 150 may be implemented as module 150-2, implemented as computer program code 153 and executed by one or more processors 152. For example, the one or more memories 155 and the computer program code 153 are configured with the one or more processors 152 to cause the RAN node 170 to perform one or more of the operations as described herein. It should be noted that the functionality of the module 150 may be distributed, such as distributed between the DU 195 and the CU 196, or may only be implemented in the DU 195.

[0016] One or more network interfaces 161 communicate over a network, such as via links 176 and 131. Two or more gNBs 170 may communicate, for example, using link 176. Link 176 may be wired or wireless or both and may implement, for example, an Xn interface for 5G, an X2 interface for LTE, or other suitable interfaces for other standards.

[0017] The one or more buses 157 may be address, data, or control buses and may include any interconnection mechanism, such as a series of lines on a motherboard or integrated circuit, optical fiber or other optical communication equipment, wireless channels, and the like. For example, the one or more transceivers 160 may be implemented as a remote radio head (RRH) 195 for LTE, or a distributed unit (DU) 195 for a 5G gNB implementation, with other elements of the RAN node 170 possibly in a different physical location from the RRH / DU, and the one or more buses 157 may be implemented in part as optical fiber cables or other suitable network connections, for example, to connect the other elements of the RAN node 170 (e.g., a central unit (CU), gNB-CU) to the RRH / DU 195. Reference numeral 198 also indicates these suitable network links.

[0018] It should be noted that while the description herein indicates that a "cell" performs a function, it should be clear that the equipment forming the cell will perform the function. A cell constitutes part of a base station. That is, there can be multiple cells per base station. For example, there may be three cells for a single carrier frequency and associated bandwidth, with each cell covering one-third of a 360-degree area, such that the coverage area of ​​a single base station covers approximately an ellipse or circle. Furthermore, each cell can support a single carrier, and a base station can use multiple carriers. Thus, if there are three 120-degree cells and two carriers per carrier, the base station has a total of six cells.

[0019] The wireless network 100 may include one or more network elements 190, which may include core network functions, providing connectivity to additional networks, such as telephone networks and / or data communication networks (e.g., the Internet), via one or more links 181. Such core network functions for 5G may include an Access and Mobility Management Function (AMF) and / or a User Plane Function (UPF) and / or a Session Management Function (SMF). Such core network functions for LTE may include an MME (Mobility Management Entity) / SGW (Serving Gateway) function. Note that these are merely example functions that may be supported by the network element 190, and both 5G and LTE functions may be supported. The RAN node 170 is coupled to the network element 190 via a link 131. The link 131 may be implemented, for example, as an NG interface for 5G, or an S1 interface for LTE, or other appropriate interface for other standards. Network element 190 includes one or more processors 175, one or more memories 171, and one or more network interfaces (N / WI / F) 180 interconnected through one or more buses 185. The one or more memories 171 include computer program code 173. The one or more memories 171 and computer program code 173 are configured to cause network element 190 to perform one or more operations on the one or more processors 175.

[0020] Wireless network 100 may implement network virtualization, which is the process of combining hardware and software network resources and network functions into a single software-based management entity: a virtual network. Network virtualization involves platform virtualization, which is often combined with resource virtualization. Network virtualization is categorized as either external, combining many networks or portions of networks into virtual units, or internal, providing network-like functionality in software containers on a single system. It should be noted that virtualized entities resulting from network virtualization are still implemented at some level using hardware, such as processor 152 or 175 and memory 155 and 171, and that such virtualized entities create technical effects.

[0021] The computer-readable memories 125, 155, and 171 may be of any type suitable for the local technology environment and may be implemented using any suitable data storage technology, such as semiconductor-based memory devices, flash memory, magnetic memory devices and systems, optical memory devices and systems, fixed memory, and removable memory. The computer-readable memories 125, 155, and 171 may be a means for performing storage functions. The processors 120, 152, and 175 may be of any type suitable for the local technology environment and may include, by way of non-limiting example, one or more of a general-purpose computer, a special-purpose computer, a microprocessor, a digital signal processor (DSP), and a processor based on a multi-core processor architecture. The processors 120, 152, and 175 may be a means for performing functions such as control of the UE 110, the RAN node 170, and other functions as described herein.

[0022] In general, various embodiments of user equipment 110 may include, but are not limited to, cellular telephones such as smartphones, tablets, personal digital assistants (PDAs) with wireless communication capabilities, portable computers with wireless communication capabilities, image capture devices such as digital cameras with wireless communication capabilities, gaming devices with wireless communication capabilities, music storage and playback appliances with wireless communication capabilities, Internet appliances that enable wireless Internet access and browsing, tablets with wireless communication capabilities, and portable units or terminals incorporating combinations of such functionality.

[0023] The features as described herein are described with respect to a four-step RACH by way of example. Nevertheless, the features as described herein are equally applicable to a two-step RACH. As noted above, 5G NR supports two contention-based random access (CBRA) procedures: a four-step RACH (Rel-15) and a two-step RACH (Rel-16).

[0024] Referring also to FIG. 2, the four-step RACH procedure can be outlined as follows: 1. Msg1 (aka PRACH): The UE sends a unique preamble to the gNB over the Physical Random Access Channel (PRACH) using a unique resource called a RACH Occasion (RO).

[0025] 2. Msg2 (aka RAR): The gNB replies with a Random Access Response (RAR) message, which contains the detected preamble ID, a time lapse command, TC-RNTI, and an UL grant for the transmission of Msg3 on the PUSCH.

[0026] 3. Msg3 (aka RRC Request): The UE responds to Msg2 via the scheduled PUSCH with an ID for contention resolution.

[0027] 4. Msg4 (aka RRC Setup): The gNB transmits a contention resolution message along with the contention resolution ID.

[0028] Upon receiving Msg4, the UE sends an ACK on the PUCCH if its contention resolution ID is carried by Msg4. This completes the four-step RACH. It is worth noting that before Msg1, there is also a preliminary step of sending and receiving synchronization signal blocks (SSBs), i.e., DL beam sweeping, which is not formally part of the RACH procedure. As a result of this preliminary step, the UE selects the index of the preferred SSB beam and decodes the associated PBCH for MIBs, SIBs, etc. This index is also used by the UE to identify the appropriate RO for preamble transmission (Msg1) according to the SSB-to-RO mapping implicitly conveyed by SIB1.

[0029] The 2-step RACH is similar to the 4-step RACH presented above, but Msg1 and Msg3 are combined into MsgA and sent out without waiting for intervening feedback from the UE (traditionally Msg2). Similarly, the gNB combines Msg2 and Msg4 into MsgB. It is straightforward to apply the solutions disclosed herein for Msg1 to the preamble / Msg1 portion of MsgA.

[0030] The following can be noted from the latest work item description for Rel-18 UL Coverage Enhancement [RP-221858]: "[...] Specify the following PRACH coverage enhancements (RAN1, RAN2): Multiple PRACH transmissions using the same beam for a 4-step RACH procedure o Study PRACH transmission using different beams for the 4-step RACH procedure and specify, if justified Note 1: PRACH enhancements are targeted at FR2 and may also be applicable to FR1, where applicable. Note 2: PRACH enhancements are targeted at short PRACH formats and may also be applicable to other formats, if applicable.

[0031] [···]” It can be observed from the above Work Item Description (WID) that Msg1 (PRACH) repetition (or also referred to as multiple PRACH transmission in the work item description) will be specified for 5G NR in Rel-18. The terms PRACH repetition and multiple PRACH transmission are used interchangeably herein.

[0032] At RAN1#111, the following agreements were reached: agreement In case of multiple PRACH transmissions using the same Tx beam, at least the SSB-RSRP threshold is used to determine the number of PRACH transmissions for at least the first RACH attempt. - Note: Whether multiple PRACH transmissions should be supported is discussed separately.

[0033] The agreement states that if the measured SSB-RSRP from the UE is lower than one or more configured thresholds, the UE uses such information to determine whether to perform multiple PRACH transmissions and the number of PRACH transmissions for the first RACH attempt. Different configured thresholds (if multiple thresholds are configured) create different SSB-RSRP ranges (also called coverage enhancement levels), each assigned to a different number of repetitions. Ultimately, the UE should select the number of PRACH repetitions based on the measured SSB-RSRP. An example of such operation (relating SSB-RSRP to the number of PRACH repetitions) is shown in Figure 3, where two SSB-RSRP thresholds are configured and the UE has measured an SSB-RSRP of -82 dBm, which falls within the first SSB-RSRP range, and therefore should transmit a PRACH with two repetitions.

[0034] Yet, this agreement does not fully address further conditions to be used by the UE to determine the number of PRACH transmissions for the first or subsequent RACH attempts ("at least the SSB-RSRP threshold is used to determine..."). Features as described herein complement this agreement. In particular, features as described herein can be used to define further conditions to be used by the UE to determine the number of PRACH transmissions for the first and subsequent RACH attempts.

[0035] Multiple PRACH transmissions (or PRACH repetitions) are expensive in terms of network resources, since the gNB must reserve specific resources (RACH occasions (ROs) or preambles) for UEs transmitting PRACH repetitions that differ from the "legacy" resources utilized by UEs transmitting PRACH without repetitions. This further implies that the number of resources reserved for PRACH repetitions will be minimized by the gNB, increasing the collision probability for UEs transmitting PRACH repetitions. In addition, PRACH repetitions increase the access latency of the UE, especially when considering that the resources available for PRACH repetitions are not always contiguous in time (e.g., in time division duplex (TDD) systems). Given these limitations, it is desirable to ensure that the UE is at, or at least near, maximum power before triggering a PRACH repetition.

[0036] In setting the SSB-RSRP threshold, the gNB may have to estimate an appropriate value for the SSB-RSRP threshold by considering the expected output power of the UEs for a particular frequency range to ensure that only maximum-power or at least near-maximum-power UEs transmit PRACH with repetition. Nevertheless, estimating the expected UE power is not straightforward since different UEs have different capabilities in terms of available output power.

[0037] Based on these considerations, the configured SSB-RSRP threshold may be suboptimal in some scenarios, where some UEs may receive SSBs with an RSRP below the threshold (and thus permitted to perform repetitions). Even if the UE does not end up transmitting the PRACH at maximum output power, the UE's actual available power is greater than the expected UE maximum output power (from the gNB) used to set the SSB-RSRP threshold. This can impact network performance, as UEs that do not require PRACH repetitions (i.e., UEs that are not at maximum output power and can meet PRACH link budget requirements) are still transmitting PRACH with repetitions, increasing their access latency and occupying already scarce resources for PRACH repetitions.

[0038] Using the features described herein, a method may be provided for allowing a UE to transmit PRACH repetitions in predetermined circumstances, such as only when the UE output power is above a certain threshold. In particular, as an example, a set of one or more conditions to be observed by the UE for the UE's output power may be defined such that the UE should be able to transmit PRACH with repetitions only if the output power reaches a certain threshold, even if the SSB-RSRP measured by the UE is below a configured SSB-RSRP threshold (as described above). Additionally, a procedure may be provided for the UE to adapt its measured SSB-RSRP measurement value over different PRACH attempts, ultimately adapting the number of transmitted PRACH repetitions. Additionally or alternatively, a procedure may be provided for the UE to adapt its configured SSB-RSRP threshold over different PRACH attempts, ultimately adapting the number of transmitted PRACH repetitions.

[0039] The following aspects characterize examples of UE transmission of PRACH repetition problems with the additional condition that the UE output power is above a particular UE output power threshold.

[0040] In one example embodiment, the UE output power threshold is configured by the network via higher layer signaling (e.g. SIB1) and is determined by the UE as such.

[0041] In one example embodiment, multiple UE output power thresholds are configured by the network via higher layer signaling (e.g., SIB1), with each threshold associated with a UE power class (i.e., a UE maximum output power for each class). The UE determines the threshold associated with this particular UE power class as the threshold to use.

[0042] In one example embodiment, one or more UE output power thresholds are specified and the UE determines the UE output power threshold to be used via the specification.

[0043] In another example embodiment, the UE output power thresholds are set or specified as absolute power values ​​(one per power class, if applicable).

[0044] In another example embodiment, the UE output power threshold is set or specified as a relative power value from the maximum power supported by a particular UE power class (e.g., 23 dBm to X dB for PC3).

[0045] In another example embodiment, the UE output power threshold is set or specified as a relative power value from a reference value or the like, which may itself be set or specified.

[0046] In one example embodiment, the condition on UE output power may be additional and complementary to the condition on measured SSB-RSRP. The UE transmits PRACH repetitions only if the output power is above a determined UE output power threshold. In this example, two conditions are required for there to be multiple PRACH transmissions (PRACH repetitions): one condition is that the SSB-RSRP is below a threshold, and the other condition is that the output power is above another, different threshold. If both conditions are met, the UE can transmit PRACH repetitions (multiple PRACH transmissions). If one of the two conditions is not met, the UE can transmit PRACH only once, without repetitions, as indicated by 514 in FIG. 5.

[0047] As noted above, even if the actual SSB-RSRP value measured at the UE during different PRACH attempts does not change, the UE uses a new correction value. That is, a procedure may be provided for adapting the measured SSB-RSRP value during different PRACH attempts. This is particularly advantageous when multiple SSB-RSRP thresholds are configured and multiple values ​​are set for multiple PRACH transmissions. The UE's decision regarding the number of PRACH repetitions for a particular PRACH attempt may be based on a power difference value (e.g., in dB) used by the UE to correct (i.e., increase or decrease) the SSB-RSRP measurement. In other words, for a particular PRACH attempt, the UE may subtract the power difference value from the originally measured SSB-RSRP, check which RSRP range the newly calculated value falls into (e.g., the range shown in FIG. 3 and associated with the number of PRACH repetitions), and transmit the PRACH with the newly determined number of repetitions. The method is outlined in Figure 4 (SSB-RSRP adaptation procedure for the second PRACH attempt, where X [dB] refers to the value of the "power difference" in the so-called second example embodiment). The adaptation procedure is also discussed in more detail below.

[0048] The assumption here is that when the UE fails a PRACH attempt, it will perform a power ramp-up on its transmit power based on already standardized procedures. Thus, the power requested for the PRACH (and transmitted by the UE if not already at maximum power) will increase with the number of PRACH attempts. Furthermore, it is assumed that multiple PRACH repetition values ​​are configured by the gNB, as explained above, and each value is associated with a range of RSRP values.

[0049] In one example embodiment, the power difference value is determined by the UE as the difference between the requested or determined power for the current PRACH attempt (as calculated via the power control algorithm and power ramp-up procedure) and the configured / determined UE output power threshold.

[0050] In another example embodiment, the value of the power difference is fixed for all PRACH attempts and is set by the network via higher layer signaling.

[0051] In another example embodiment, the value of the power difference is not fixed for all PRACH attempts, but an initial value may be set by the network via higher layer signaling. The initial value may then be adjusted by the UE as a function of the PRACH attempt. For example, the UE may use X dB for the second PRACH attempt, X+Z dB for the third PRACH attempt, and so on.

[0052] As noted above, the UE may be provided with a procedure for adapting the configured SSB-RSRP threshold value and using the new modified value in different PRACH attempts. This is particularly advantageous when multiple SSB-RSRP thresholds are configured and multiple values ​​for multiple PRACH transmissions are configured, and the measured SSB-RSRP changes in the second PRACH attempt compared to the one described in the paragraph above. The UE's decision on the number of PRACH repetitions in a particular PRACH attempt may be based on a power difference value (e.g., in dB) that the UE uses to modify (i.e., increase or decrease) the configured SSB-RSRP threshold. In other words, in a particular PRACH attempt, the UE may add the power difference value from the configured SSB-RSRP threshold, check which RSRP range the measured SSB-RSRP falls into, and transmit the PRACH with the newly determined number of repetitions. An example alternative method is outlined in Figure 11 (SSB-RSRP threshold adaptation procedure for second PRACH attempt, where X [dB] refers to the so-called "power difference" value in the second example embodiment). This adaptation procedure is also discussed in more detail below.

[0053] The assumption here is that when the UE fails a PRACH attempt, it will perform a power ramp-up on its transmit power based on already standardized procedures. Thus, the requested power for the PRACH (and transmitted by the UE if not already at maximum power) will increase with the number of PRACH attempts. Furthermore, as explained above, it is assumed that multiple values ​​of PRACH repetition are configured by the gNB, and each value is associated with a range of RSRP values.

[0054] In one example embodiment, the power difference value is determined by the UE as the difference between the requested or determined power for the current PRACH attempt (as calculated via the power control algorithm and power ramp-up procedure) and the configured / determined UE output power threshold.

[0055] In another example embodiment, the value of the power difference is fixed for all PRACH attempts and is set by the network via higher layer signaling.

[0056] In another example embodiment, the value of the power difference is not fixed for all PRACH attempts, but may be set to an initial value by the network via higher layer signaling. The initial value may then be adjusted by the UE as a function of the PRACH attempt. For example, the UE may use X dB for the second PRACH attempt, X+Z dB for the third PRACH attempt, etc.

[0057] 5-7, flowcharts for implementation examples are shown. The following are procedures of various embodiments in the flowcharts between the gNB 170 and the UE 110:

[0058] Step 1: Setting the UE output power threshold (Pt) and SSB-RSRP threshold (St) via higher layer signaling (eg, SIB1), as indicated by step 502.

[0059] This example implementation assumes that the gNB configures only one SSB-RSRP threshold (e.g., for one power class) and only one UE output power threshold. Without loss of generality, the operation can be extended to multiple configured thresholds.

[0060] b. At the same time, as indicated by 504, the gNB may configure the number of PRACH repetitions to be performed if the condition is met. Assuming that only one SSB-RSRP threshold is configured, this example may comprise only one number of repetitions to be configured. If multiple SSB-RSRP thresholds are configured, different numbers of PRACH repetitions may be configured, for example, as shown in FIG. 3.

[0061] Step 2: Periodic transmission of SSB with a period equal to, for example, 20 milliseconds, can follow the standardized procedure as shown by 506. Different SSB indexes can be transmitted by the gNB in a so-called SSB burst as an option.

[0062] Step 3: Measurement of SSB-RSRP by the UE for the SSB index selected as the best, for example, with the maximum SSB-RSRP, can be provided as shown by 508. However, the selection of the best index is not related to the content of the features described herein.

[0063] Step 4: Calculation by the UE of the power (P1) required for PRACH transmission in the first attempt following the standardized procedure is shown in 510.

[0064] a. An example of the power control formula for PRACH is shown in 3GPP TS38.213.

[0065] Step 5: In this example, as shown in 512, the UE can compare P1 with the set threshold Pt, and further compare the measured SSB-RSRP with the set threshold St. This involves the determination that the measured SSB-RSRP is less than (<St).

[0066] For the example shown in Figure 5, (as an example) when P1 < Pt, the UE can set the number of PRACH transmissions to 1 even when the measured SSB-RSRP is below the threshold St. One (1) PRACH transmission can be set to the calculated power P1. The UE can proceed to Step 6 (514).

[0067] The UE may transmit the PRACH without repetition (only one transmission) as shown in step 6:514. If the UE recognizes that the PRACH attempt failed as shown by 515 in Figure 7 because, for example, the UE did not receive Msg2 within an appropriate time, such as a configured ra-responseWindow, the UE may proceed to step 7 (516, 518) as further described below and use an adaptation procedure.

[0068] Referring also to FIG. 6, if the UE 110 determines that P1 > Pt, as shown by 512′ in FIG. 6, the UE may send the PRACH with repetitions at the calculated power P1, as shown at 520′. If Pt is greater than or equal to the UE maximum output power, the UE may send the PRACH with repetitions at power Pt. PRACH repetition transmission is also known as transmitting the PRACH using multiple transmissions or multiple PRACH transmissions. The UE may use a predetermined number of repetitions, such as the number of repetitions indicated by the network node (gNB 170) at 504.

[0069] Referring also to FIG. 7, if it is determined that the PRACH attempt has failed as indicated by 515, a power ramp-up process may be used.

[0070] Step 7: In this example, step 7 would occur with the detected failure at 515. As shown at 516 and 518, the UE may perform a power ramp-up based on standardized procedures (3GPP TS38.321) and increase the transmit power by a value delta_P (ΔP) (e.g., a configured value) for the second PRACH attempt, such that P2=P1+delta_P.

[0071] a. If P2>Pt (for example), the UE can go to step 8 (520).

[0072] b. If P2 is still smaller than Pt (P2 < Pt), the UE can return to 514 and transmit the PRACH without repetition at power P2. If there is still a PRACH trial failure 515, the process can proceed to 516 and 518 again, increasing P2 to another power P3. After 518 again, if the process still cannot proceed to 520, the process can repeat again as many times as necessary and possible.

[0073] Step 8: As shown at 520, when it is determined that both conditions (P2 > Pt and SSB-RSRP < St) are satisfied, the UE may transmit the PRACH with the set number of repetitions and the determined power P2 or P3 or P(n).

[0074] Regarding the adaptation procedure, the adaptation may use both increasing the power and increasing the number of repetitions. Step 7 refers to performing a power ramp-up based on a standardized procedure. Also, FIG. 4 shows that a new calculated SSB-RSRP 404 is calculated for a subsequent (second) PRACH trial. As can be seen in FIG. 4, the measured SSB-RSRP 402 was determined to be within the first RSRP range 403 that should provide the first PRACH repetition. The new calculated value of the calculated SSB-RSRP 404 shown in FIG. 4 is a calculated value that falls within a second RSRP range 405 corresponding to a second different number of PRACH repetitions, where the second different number of repetitions is greater than the number of repetitions of the first PRACH repetition. Thus, the measured value of the SSB-RSRP is reduced to the new calculated value, and then the new calculated value is compared again with St (where St in this case is not a single threshold as in the examples of FIGS. 5, 6, and 7, but a set of multiple SSB-RSRP thresholds). This results in a new calculated value (see FIG. 4) and provides a different, greater number of second PRACH repetitions to proceed to step 7 instead of step 6. Note that the described SSB-RSRP adaptation procedure is only an option and may not be provided. Additionally, other forms of SSB-RSRP adaptation procedures may be provided.

[0075] 10, a flowchart is shown for an example implementation of an SSB-RSRP adaptation procedure when the measured SSB-RSRP is adapted. When the configured SSB-RSRP threshold is adapted as in some embodiments, the procedure may be the same as the flowchart of FIG. 10, except that the adaptation target at 1014 is the configured SSB-RSRP threshold rather than the measured SSB-RSRP, and the determination of the number of multiple PRACH transmissions at 1016 is based on the adapted SSB-RSRP threshold. Below are example steps in the flowchart between the gNB 170 and the UE 110:

[0076] Step 1: The gNB (170) configures an SSB-RSRP threshold for determining the number of PRACH repetitions, as indicated by 1002, and transmits the configuration to the UE (110). One implementation example of such a configuration is shown in FIG.

[0077] Step 2: The gNB (170) configures a power difference value for the SSB-RSRP adaptation procedure in different PRACH attempts and transmits the configuration to the UE (110), as indicated by 1004. In this example implementation, the value is configured by the gNB, but in other example embodiments, it is contemplated that the value may be determined by the UE based on its calculated power for PRACH transmissions based on a power control algorithm and a power ramp-up procedure.

[0078] As indicated by step 3:1006, a measurement of the SSB-RSRP by the UE (110), for example for the best selected SSB index having the largest SSB-RSRP, may be provided or determined.

[0079] Step 4: A determination of the number of multiple PRACH transmissions for the first PRACH attempt by the UE (110) may be provided or determined, as indicated by 1008. Such a determination may be based on the measured SSB-RSRP at 1006 and the configured SSB-RSRP threshold at 1002. For example, the UE may determine the number R1 of multiple PRACH transmissions.

[0080] As shown in step 5:1010, the UE transmits R1 multiple PRACH transmissions.

[0081] Step 6:1012 shows when the PRACH attempt (ie, the first PRACH attempt) fails.

[0082] As shown in step 7:1014, an adaptation of the measured SSB-RSRP at 1006 may be provided. The adaptation is based on the power difference value. In one example, the measured SSB-RSRP at 1006 is decreased by the amount of the power difference value provided at 1004.

[0083] Step 8: The adapted SSB-RSRP value may be used to determine the number of PRACH multiplex transmissions for the second PRACH attempt in 1016. The UE 110 may compare the adapted SSB-RSRP value with the configured SSB-RSRP threshold in 1002 to determine a value R2 for multiple PRACH transmissions.

[0084] As shown in step 9:1018, UE 110 may transmit R2 multiple PRACH transmissions.

[0085] 10, the SSB-RSRP adaptation procedure stops at the second PRACH attempt for clarity, but it should not be assumed that this is the general mode of operation. For example, if the second PRACH attempt 1018 fails again, then for the third PRACH attempt, the SSB-RSRP value adapted at 1014 may again be decreased by the power delta value to provide a new value for the adapted SSB-RSRP value to be used for determining the number of multiple PRACH transmissions for the third PRACH attempt. The same procedure may be followed for subsequent PRACH attempts.

[0086] It should be further noted that when the power difference value increases as a function of PRACH attempts, as in accordance with embodiments of the present application, the adaptation of the measured SSB-RSRP can be based on either the most recently adapted SSB-RSRP or the measured SSB-RSRP. For example, referring to FIG. 10, if the configured power difference value is X, 1014 may provide the measured SSB-RSRP minus X as the adapted SSB-RSRP value. If the PRACH transmission again fails and a third PRACH attempt occurs, the configured power difference value may be increased by Z (i.e., X+Z), and the value (X+Z) is subtracted from either the adapted SSB-RSRP in 1014 or the measured SSB-RSRP in 1006.

[0087] Note that a distinction should be made between transmit power (referred to as P1 / P2) and SSB-RSRP received and measured power. The adaptation process primarily refers to SSB-RSRP received power, but can be linked to a power ramp-up procedure, where the power difference value is not set by the gNB but determined by the UE. By increasing the power required for transmission via the power ramp-up procedure (even if the UE is subsequently unable to provide such power), the difference value between such increased power and the power threshold Pt can be increased to lower the SSB-RSRP, allowing for a greater number of iterations. Using features as described herein, the transmit power can be increased with each retry following the power ramp-up procedure. This ultimately leads to an increasingly larger difference value, and therefore an increasingly smaller SSB-RSRP, leading to more iterations. Referring to FIG. 10, the larger difference value for the possible third PRACH attempt can be applied to either the adapted SSB-RSRP at 1014 or the measured SSB-RSRP at 1006.

[0088] Referring also to FIG. 8, according to one example, measuring a received power of a reference signal at the user equipment, as indicated by block 802; determining at the user equipment based on the measurement of the received power that the physical random access channel will be transmitted using multiplexed transmission, as indicated by block 804; determining at the user equipment a transmit power of the physical random access channel, as indicated by block 806; determining at the user equipment a power threshold, as indicated by block 808; and determining that the determined transmit power is less than the power threshold and sending at the user equipment the physical random access channel without multiplexed transmission of the physical random access channel, as indicated by block 810; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel at the user equipment using multiplexed transmission of the physical random access channel; An example method is provided that includes at least one of:

[0089] The method may further include increasing a transmission power at the user equipment based on the random access procedure failure and determining an increase in the number of multiple transmissions of the physical random access channel. The determination of the increase in the number of multiple transmissions of the physical random access channel may be based at least in part on the increased transmission power being greater than a power threshold. Determining the power threshold may include receiving the power threshold from a network node. The method may further include determining a different power threshold including receiving the different power threshold from the network node. The different power threshold may be a synchronization signal block reference signal received power (SSB-RSRP) threshold. The power threshold may be a user equipment output power threshold. Determining the power threshold may include receiving multiple power thresholds and selecting a power threshold from the received multiple power thresholds. It should be noted that the determining steps noted above need not be in a particular order or sequence. The order or sequence of the steps may be varied and may occur in any suitable type, order, or sequence.

[0090] The power threshold selection may be based at least in part on a power class of the user equipment. The power threshold selection may be based at least in part on a predetermined configuration or specification of the user equipment. Determining the power threshold may include modifying a power threshold value to determine the power threshold. The power threshold value may be received from a network node, and the power threshold value may be reduced by the user equipment by a determined amount to provide the power threshold. Determining the power threshold may include using a power value relative to a maximum power supported by the user equipment or a power value relative to a power class of the user equipment. Determining the power threshold may include using a power value relative to a reference power value. The method may further include determining a first value of the first measured power, reducing the first value by a second value to form a third new value, and determining the number of physical random access channel multiplexing transmissions using the third new value. The second value may be a power difference determined by the user equipment and is determined by the UE as the difference between the power required for PRACH transmissions and the power available at the UE. The second value may be a power difference received at the user equipment from the network node. The determination of the transmit power of the physical random access channel can be based on a power control algorithm. The determination of the transmit power of the physical random access channel can include calculating the transmit power of the physical random access channel. The reference signal can be a synchronization reference signal or a channel state information reference signal.

[0091] Example embodiments include at least one processor and at least one non-transitory memory, which, when executed on the at least one processor, perform the following functions: measuring, at the apparatus, a received power of a reference signal; determining, at the apparatus, based on the measurement of the received power, that a physical random access channel will be transmitted using multiplexed transmission; determining, at the apparatus, a transmit power for the physical random access channel; and determining, at the apparatus, a power threshold. determining that the determined transmission power is less than a power threshold, and transmitting the physical random access channel with the device without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel by the device using multiplexed transmission of the physical random access channel; with at least one of at least one non-transitory memory storing instructions that cause the device to perform the An apparatus may be provided comprising:

[0092] The device may be a user equipment. When executed on at least one processor, the instructions may cause the device to increase a transmission power at the device based on a random access procedure failure and determine an increase in the number of multiple transmissions of a physical random access channel. The determination of the increase in the number of multiple transmissions of the physical random access channel may be based at least in part on the increased transmission power being greater than a power threshold. The determination of the power threshold may include receiving a power threshold from a network node. The power threshold may be a user equipment output power threshold. The determination of the power threshold may include receiving a plurality of power thresholds and selecting a power threshold from the received plurality of power thresholds. The selection of the power threshold may be based at least in part on a power class of the device. The selection of the power threshold may be based at least in part on a predetermined setting or specification of the device. The determination of the power threshold may include modifying a value of the power threshold to determine the power threshold. The value of the power threshold may be received from the network node, and the value of the power threshold may be reduced by the device by a determined amount to provide the power threshold. The determination of the power threshold may include using a power value relative to a maximum power supported by the device or a power value relative to a power class of the device. Determining the power threshold may include using a power value relative to a reference power value. Determining the transmit power of the physical random access channel may be based on a power control algorithm. Determining the transmit power of the physical random access channel may include calculating the transmit power of the physical random access channel. The reference signal may be a synchronization reference signal or a channel state information reference signal.

[0093] Example embodiments may be provided with a non-transitory program storage device readable by the device tangibly embodying a program of instructions executable by the device to perform operations, the operations including measuring, at the device, a received power of a reference signal; determining, at the device, based on the measurement of the received power, that a physical random access channel will be transmitted using multiplexed transmission; determining, at the device, a transmit power of the physical random access channel; and determining, at the device, a power threshold. determining that the determined transmission power is less than a power threshold, and transmitting the physical random access channel with the device without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel by the device using multiplexed transmission of the physical random access channel; with at least one of Includes.

[0094] Example embodiments include means for measuring, at the apparatus, a received power of a reference signal; means for determining, at the apparatus, based on the measurement of the received power, that a physical random access channel will be transmitted using multiplexed transmission; means for determining, at the apparatus, a transmit power of the physical random access channel; and means for determining, at the apparatus, a power threshold. determining that the determined transmission power is less than a power threshold, and transmitting the physical random access channel with the device without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel by the device using multiplexed transmission of the physical random access channel; and means for performing at least one of An apparatus may be provided comprising:

[0095] Example embodiments include circuitry configured to measure, at the apparatus, the received power of a reference signal; circuitry configured to determine, at the apparatus, based on the measurement of the received power, that a physical random access channel will be transmitted using multiplexed transmission; circuitry configured to determine, at the apparatus, the transmit power of the physical random access channel; and circuitry configured to determine, at the apparatus, a power threshold. determining that the determined transmission power is less than a power threshold, and transmitting the physical random access channel with the device without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel by the device using multiplexed transmission of the physical random access channel; a circuit device configured for at least one of An apparatus may be provided comprising:

[0096] Referring also to FIG. 9 , an example method may be provided that includes determining, at a user equipment, a first value of a first measured power, as indicated by block 902; reducing the first value by a second value to form a third new value, as indicated by block 904; and determining a number of physical random access channel multiplex transmissions using the third new value, as indicated by block 906.

[0097] The second value may be a power difference determined by the user equipment. The second value may be a determined power difference received at the user equipment from a network node. The method includes determining at the user equipment a first power threshold and a second, different power threshold, determining that the first measured power is less than a third, new value, and determining that the second calculated power is less than a second, different power threshold, and based on determining that the third new value is less than the first power threshold and based on determining that the second calculated power is less than the second, different power threshold, sending the physical random access channel at the user equipment without repeating the physical random access channel; or and transmitting, at the user equipment, the physical random access channel using multiple transmissions based on determining that the second calculated power is greater than a second, different power threshold and determining that the third new value is less than the first power threshold and based on determining that the second calculated power is greater than the second, different power threshold. with at least one of It may further include:

[0098] In one example embodiment, determining a first power threshold and a second, different power threshold at the user equipment, determining that the first measured power is less than the first power threshold; determining that the second calculated power is less than a second, different power threshold, and based on determining that the first measured power is less than the first power threshold and based on determining that the second calculated power is less than the second, different power threshold, sending the physical random access channel at the user equipment without repeating the physical random access channel; or determining that the second calculated power is greater than a second, different power threshold, and based on determining that the first measured power is less than the first power threshold and based on determining that the second calculated power is greater than the second, different power threshold, sending the physical random access channel with at least one repetition of the physical random access channel at the user equipment. The second power may be a UE output power, which may be calculated via a power control formula for the PRACH as defined in 3GPP TS38.213.

[0099] Using features as described herein, example embodiments may be provided that include SSB-RSRP adaptation that adapts the SSB-RSRP threshold rather than the measured SSB-RSRP, which may be advantageous when the measured SSB-RSRP varies significantly across different PRACH attempts.

[0100] The term "non-transitory" as used herein is a limitation of the medium itself (i.e., tangible and not a signal) as opposed to a limitation to data storage permanence (e.g., RAM vs. ROM).

[0101] As used in this application, the term "circuit" means: (a) hardware-only circuit implementations (e.g., implementations in only analog and / or digital circuitry); (b) A combination of hardware circuits and software (If applicable): (i) combinations of analog and / or digital hardware circuitry and software / firmware; and (ii) any portion of a hardware processor together with software (including a digital signal processor, software, and memory that work together to cause a device such as a mobile phone or server to perform various functions); and (iii) Hardware circuitry and / or processors, such as microprocessors or portions of microprocessors, that require software (e.g., firmware) to operate, but that may be absent when not necessary for operation. A combination of hardware circuits and software such as It may refer to one or more or all of the following:

[0102] This definition of circuit applies to all uses of the term in this application, including in any claims. As a further example, as used in this application, the term circuit also covers simply a hardware circuit or processor (or processors), or portions of a hardware circuit or processor, as well as its (or their) accompanying software and / or firmware implementations. The term circuit also covers, for example, and where applicable to particular claim elements, a baseband or processor integrated circuit for a mobile device, or similar integrated circuit of a server, cellular network device, or other computing or network device.

[0103] It should be understood that the foregoing description is illustrative only. Various alternatives and modifications may be devised by those skilled in the art. For example, the features recited in the various dependent claims may be combined with each other in any suitable combination. Furthermore, features from different embodiments described above may be selectively combined to form new embodiments. Accordingly, the present description is intended to embrace all such alternatives, modifications, and variations that fall within the scope of the appended claims.

Claims

1. 1. A method comprising: measuring at the user equipment the received power of a reference signal; determining at the user equipment based on the received power measurement that the physical random access channel will be transmitted using multiplexed transmission; determining, at a user equipment, a transmit power of a physical random access channel; determining a power threshold at the user equipment; determining that the determined transmission power is less than a power threshold and transmitting the physical random access channel by the user equipment without multiplexing the physical random access channel; or determining that the determined transmission power is greater than a power threshold and transmitting the physical random access channel at the user equipment using multiplexed transmission of the physical random access channel; with at least one of A method comprising:

2. 10. The method of claim 1, further comprising: increasing transmission power at the user equipment based on a random access procedure failure; and determining an increase in the number of multiplexed transmissions of the physical random access channel.

3. 3. The method of claim 2, wherein the determination of increasing the number of multiplexed transmissions of the physical random access channel is based at least in part on the increased transmission power being greater than a power threshold.

4. The method of claim 1 , wherein determining the power threshold comprises receiving the power threshold from a network node.

5. The method of claim 1 , wherein the power threshold is a user equipment output power threshold.

6. The method of claim 1 , wherein determining the power threshold comprises receiving a plurality of power thresholds and selecting a power threshold from the received plurality of power thresholds.

7. The method of claim 6 , wherein the selection of the power threshold is based at least in part on a power class of the user equipment.

8. The method of claim 6 , wherein the selection of the power threshold is based at least in part on predetermined settings or specifications of the user equipment.

9. The method of claim 1 , wherein determining the power threshold comprises modifying a value of the power threshold to determine the power threshold.

10. 10. The method of claim 9, wherein the value of the power threshold is received from a network node, and the value of the power threshold is reduced by the user equipment by an amount determined to provide the power threshold.

11. The method of claim 1 , wherein determining the power threshold comprises using a power value relative to the maximum power supported by the user equipment or a power class of the user equipment.

12. The method of claim 1 , wherein determining the power threshold comprises using a power value relative to a reference power value.

13. The method according to any one of claims 1 to 4, wherein the determination of the transmission power of the physical random access channel is based on a power control algorithm.

14. 14. The method of claim 1, wherein determining the transmit power of the physical random access channel comprises calculating the transmit power of the physical random access channel.

15. The method according to any of claims 1 to 14, wherein the reference signal is a synchronization reference signal or a channel state information reference signal.

16. Apparatus comprising means for carrying out the method according to any of claims 1 to 15.

17. 1. An apparatus comprising: at least one processor; at least one non-transitory memory that, when executed by at least one processor, measuring with an apparatus the received power of a reference signal; determining at the apparatus based on the received power measurement that the physical random access channel will be transmitted using multiplexed transmission; determining, by the device, a transmit power of a physical random access channel; determining a power threshold at the device; determining that the determined transmission power is less than a power threshold, and transmitting the physical random access channel with the device without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel by the device using multiplexed transmission of the physical random access channel; with at least one of at least one non-transitory memory storing instructions that cause the device to perform the An apparatus comprising:

18. 20. The apparatus of claim 17, wherein the instructions, when executed by at least one processor, cause the apparatus to: increase a transmit power at the apparatus based on a random access procedure failure; and determine an increase in a number of multiplex transmissions of a physical random access channel.

19. 20. The apparatus of claim 18, wherein the determination of increasing the number of multiplexed transmissions of the physical random access channel is based at least in part on the increased transmission power being greater than a power threshold.

20. 20. The apparatus of claim 17, wherein determining the power threshold comprises receiving the power threshold from a network node.

21. 21. The apparatus of any one of claims 17 to 20, wherein the power threshold is a user equipment output power threshold.

22. 21. The apparatus of claim 17, wherein determining the power threshold comprises receiving a plurality of power thresholds and selecting a power threshold from the received plurality of power thresholds.

23. 23. The device of claim 22, wherein the selection of the power threshold is based at least in part on a power class of the device.

24. 23. The device of claim 22, wherein the selection of the power threshold is based at least in part on predetermined settings or specifications of the device.

25. 21. The apparatus of claim 17, wherein determining the power threshold comprises modifying a value of the power threshold to determine the power threshold.

26. 26. The apparatus of claim 25, wherein the value of the power threshold is received from a network node, and the value of the power threshold is reduced by the apparatus by an amount determined to provide the power threshold.

27. 21. The device of any one of claims 17 to 20, wherein determining the power threshold comprises using a power value relative to a maximum power supported by the device or a power class of the device.

28. Determining the power threshold involves using the power value relative to a reference power value.

21. Apparatus according to any one of claims 17 to 20.

29. 21. The apparatus according to claim 17, wherein the determination of the transmission power of the physical random access channel is based on a power control algorithm.

30. 30. The apparatus of claim 17, wherein determining the transmit power of the physical random access channel comprises calculating the transmit power of the physical random access channel.

31. 31. The apparatus of any of claims 17 to 30, wherein the reference signal is a synchronization reference signal or a channel state information reference signal.

32. A non-transitory program storage device readable by an apparatus tangibly embodying a program of instructions executable by the apparatus for performing operations, the operations comprising: measuring with an apparatus the received power of a reference signal; determining at the apparatus based on the received power measurement that the physical random access channel will be transmitted using multiplexed transmission; determining, by the device, a transmit power of a physical random access channel; determining a power threshold at the device; determining that the determined transmission power is less than a power threshold, and transmitting the physical random access channel with the device without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel by the device using multiplexed transmission of the physical random access channel; with at least one of a non-transitory program storage device,

33. 1. An apparatus comprising: means for measuring the received power of a reference signal at the device; means for determining, at the apparatus, based on measurements of received power, that the physical random access channel will be transmitted using multiplexed transmission; means for determining, at the apparatus, a transmit power of a physical random access channel; means for determining a power threshold at the device; determining that the determined transmission power is less than a power threshold, and transmitting the physical random access channel with the device without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel by the device using multiplexed transmission of the physical random access channel; and means for performing at least one of the following: An apparatus comprising:

34. 1. An apparatus comprising: a circuit configured to measure, at the apparatus, the received power of a reference signal; a circuit configured to determine at the apparatus based on the received power measurement that the physical random access channel will be transmitted using multiplexed transmission; a circuit configured to determine, at the apparatus, a transmit power of a physical random access channel; a circuit configured to determine a power threshold at the device; determining that the determined transmission power is less than a power threshold, and transmitting the physical random access channel with the device without multiplexing the physical random access channel; or determining that the determined transmit power is greater than a power threshold and transmitting the physical random access channel by the device using multiplexed transmission of the physical random access channel; and a circuit configured for at least one of An apparatus comprising:

35. 1. A method comprising: determining at the user equipment a first value of a first measured power; decreasing the first value by the second value to form a third new value; determining the number of physical random access channel multiplexes using the third new value; and A method comprising:

36. 36. The method of claim 35, wherein the second value is a power difference determined by the user equipment.

37. 36. The method of claim 35, wherein the second value is a determined power difference received at the user equipment from a network node.

38. determining at the user equipment a first power threshold and a second, different power threshold; determining that the first measured power is less than a third new value; determining that the second calculated power is less than a second different power threshold and, based on determining that the third new value is less than the first power threshold and based on determining that the second calculated power is less than the second different power threshold, sending at the user equipment the physical random access channel without repetition of the physical random access channel; or and transmitting, at the user equipment, the physical random access channel using multiple transmissions based on determining that the second calculated power is greater than a second different power threshold and determining that the third new value is less than the first power threshold and based on determining that the second calculated power is greater than the second different power threshold. with at least one of 36. The method of claim 35, further comprising:

39. Apparatus comprising means for carrying out the method according to any of claims 35 to 38.

40. 39. A non-transitory program storage device readable by a device and tangibly embodying a program of instructions executable by the device to perform operations, the operations comprising any of the methods of claims 35 to 38.

41. 1. An apparatus comprising: at least one processor; at least one non-transitory memory that, when executed by at least one processor, determining at the user equipment a first power threshold and a second, different power threshold; determining that the first measured power is less than a third new value; determining that the second calculated power is less than a second different power threshold and, based on determining that the third new value is less than the first power threshold and based on determining that the second calculated power is less than the second different power threshold, sending at the user equipment the physical random access channel without repetition of the physical random access channel; or and transmitting, at the user equipment, the physical random access channel using multiple transmissions based on determining that the second calculated power is greater than a second different power threshold and determining that the third new value is less than the first power threshold and based on determining that the second calculated power is greater than the second different power threshold. with at least one of at least one non-transitory memory storing instructions that cause the device to perform the An apparatus comprising:

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