Efficient prach transmission in fallback rach procedure

Abstract

A user equipment (UE) configured to initiate a two-step random access channel (RACH) procedure to synchronize with a base station, initiate a fallback four-step RACH procedure after the two-step RACH procedure, configure a random access preamble transmission for the four-step RACH procedure, wherein configuring the random access preamble transmission includes deriving a physical random access channel (PRACH) transmission power parameter value based on a parameter used to perform a transmission during the two-step RACH procedure, and transmitting the random access preamble to the base station for the four-step RACH procedure.

Description

[0001] Priority / Incorporation by reference

[0002] This application claims priority to U.S. Provisional Application Serial No. 63 / 261,596, filed September 24, 2022, entitled “Efficient PRACH Transmission in a Fallback RACH Procedure,” the entire contents of which are incorporated herein by reference. Background Technology

[0003] User equipment (UE) can execute a random access channel (RACH) procedure to synchronize with the base station. In some networks, the UE may initially attempt a two-step RACH procedure. If the two-step RACH procedure fails, the UE can fall back to a four-step RACH procedure. Summary of the Invention

[0004] Some exemplary embodiments relate to a processor of a user equipment (UE) configured to perform operations. These operations include initiating a two-step random access channel (RACH) procedure to synchronize with a base station, initiating a four-step backtracking RACH procedure after the two-step RACH procedure, configuring random access preamble transmission for the four-step RACH procedure, wherein configuring the random access preamble transmission includes deriving physical random access channel (PRACH) transmission power parameter values ​​based on parameters used for transmissions performed during the two-step RACH procedure, and transmitting the random access preamble for the four-step RACH procedure to the base station.

[0005] Other exemplary embodiments relate to a user equipment (UE) having: a transceiver configured to communicate with a base station; and a processor communicatively coupled to the transceiver and configured to perform operations. The operations include initiating a two-step random access channel (RACH) procedure to synchronize with the base station, initiating a four-step backtracking RACH procedure after the two-step RACH procedure, configuring random access preamble transmission for the four-step RACH procedure, wherein configuring the random access preamble transmission includes deriving physical random access channel (PRACH) transmission power parameter values ​​based on parameters used for performing transmissions during the two-step RACH procedure, and transmitting the random access preamble for the four-step RACH procedure to the base station.

[0006] Another exemplary embodiment relates to a method comprising initiating a two-step random access channel (RACH) procedure to synchronize with a base station, initiating a four-step backtracking RACH procedure after the two-step RACH procedure, configuring random access preamble transmission for the four-step RACH procedure, wherein configuring the random access preamble transmission includes deriving physical random access channel (PRACH) transmission power parameter values ​​based on parameters used for performing transmissions during the two-step RACH procedure, and transmitting the random access preamble for the four-step RACH procedure to the base station. Attached Figure Description

[0007] Figure 1 Signaling diagrams of a four-step random access channel (RACH) procedure according to various exemplary embodiments are shown.

[0008] Figure 2 Signaling diagrams of a two-step RACH procedure according to various exemplary implementations are shown.

[0009] Figure 3 The diagram illustrates an exemplary scenario of executing a four-step RACH rollback procedure after a two-step RACH procedure fails, according to various exemplary embodiments.

[0010] Figure 4 A method for configuring random access preamble transmission for a four-step RACH rollback procedure is illustrated according to various exemplary embodiments.

[0011] Figure 5 A signaling diagram illustrating an example of performing multiple msgA transmissions during a failed two-step RACH procedure, according to various exemplary implementations, is shown.

[0012] Figure 6 A signaling diagram illustrating examples of multiple transmissions of msg1 performed during a four-step RACH procedure, according to various exemplary embodiments, is shown.

[0013] Figure 7 The following signaling diagram illustrates an example of deriving the PRACH transmission power parameter value of msg1 of the backtracking four-step RACH procedure based on the most recently transmitted msgA, according to various exemplary embodiments.

[0014] Figure 8 The signaling diagram shown illustrates an example of a four-step RACH procedure triggered based on the maximum transmit power level (MTPL).

[0015] Figure 9 Exemplary network arrangements according to various exemplary implementations are shown.

[0016] Figure 10Exemplary user equipment (UE) according to various exemplary embodiments are shown.

[0017] Figure 11 An exemplary base station according to various exemplary embodiments is shown. Detailed Implementation

[0018] The exemplary embodiments can be further understood with reference to the following description and related figures, wherein similar elements have the same reference numerals. The exemplary embodiments relate to user equipment (UE) configured to fall back to a four-step RACH procedure when a two-step RACH procedure fails. The exemplary embodiments introduce techniques that can reduce latency, signaling overhead, and power consumption associated with falling back to a four-step RACH procedure.

[0019] Exemplary implementations are described with reference to signaling exchange between the UE and a next-generation node B (gNB) in a fifth-generation (5G) New Radio (NR) network. The UE described herein refers to any suitable electronic device configured with hardware, software, and / or firmware for exchanging information (e.g., control information) and / or data with the network. Furthermore, references to the gNB and 5G NR network are provided as examples and are not intended to limit the exemplary implementations in any way. Exemplary implementations can be applied to any type of base station or access node configured to participate in a four-step RACH backoff procedure and deployed within any suitable type of network.

[0020] The UE can execute a RACH procedure to synchronize with the gNB. For example, the UE can execute a RACH procedure for initial access or establishing a Radio Resource Control (RRC) connection state. Those skilled in the art will understand that the terms "two-step RACH procedure" and "four-step RACH procedure" refer to the procedures defined by the 3GPP (3rd Generation Partnership Project). A two-step RACH procedure involves two specific types of messages, such as msgA and msgB. The following section discusses... Figure 2 Signaling diagram 200 provides a general overview of the two-step RACH procedure.

[0021] The four-step RACH procedure includes four specific message types, such as msg1, msg2, msg3, and msg4. The following is about... Figure 1 Signaling diagram 100 provides a general overview of the four-step RACH procedure.

[0022] As mentioned above, if the two-step RACH procedure fails, the UE can be configured to fall back to the four-step RACH procedure. The following section discusses... Figure 3 Signaling diagram 300 provides an example of this type of rollback scenario.

[0023] The exemplary implementation introduces techniques related to the transmission of msg1 for reversing a four-step RACH procedure. As described in more detail below, the exemplary techniques increase the likelihood of receiving a response to the transmission of msg1, and thus increase the likelihood of a successful four-step RACH procedure. These exemplary techniques can be used in conjunction with currently implemented four-step RACH procedures, future implementations of four-step RACH procedures, or independently of other four-step RACH procedures. Specific examples of each of these exemplary techniques are provided in detail below.

[0024] Figure 1 Signaling diagram 100 illustrates a four-step RACH procedure according to various exemplary embodiments. Signaling diagram 100 provides a general overview of the four-step RACH procedure and includes UE 110 and gNB 120A.

[0025] In step 150, UE 110 transmits a random access preamble (e.g., msg1) to gNB 120A. The random access preamble may be transmitted over PRACH. In step 155, in response to msg1, gNB 120A transmits a random access response (RAR) (e.g., msg2) to UE 110. The RAR may include an indication that the random access preamble was successfully received and other information, such as, but not limited to, resource allocation information for subsequent RACH procedure transmissions (e.g., msg3, etc.).

[0026] In step 160, UE 110 transmits an RRC connection request (e.g., msg3) to gNB 120A. Those skilled in the art will understand that an RRC connection request is an example of msg3. The content and type of the message configured as msg3 can vary depending on the relevant scenario. However, msg3 is beyond the scope of this exemplary embodiment.

[0027] In 165, gNB 120A transmits a contention resolution message (e.g., msg4) to UE 110. In some implementations, UE 110 may transmit a Hybrid Automatic Request (HARQ) acknowledgment (ACK) in response to msg4 during or after the RACH procedure.

[0028] Figure 2 Signaling diagram 200 illustrates a two-step RACH procedure according to various exemplary embodiments. Signaling diagram 200 provides a general overview of the two-step RACH procedure and includes UE 110 and gNB 120A.

[0029] In step 205, UE 110 transmits the random access preamble and PUSCH data (e.g., msgA) to gNB 120A. The random access preamble can be a PRACH transmission. Typically, msgA can be represented as a combination of msg1 and msg3. In step 210, gNB 120A transmits RAR (e.g., msgB) to UE 110. Typically, msgB can be represented as a combination of msg2 and msg4.

[0030] Figure 3 Signaling diagram 300 illustrates an exemplary scenario in which a four-step RACH procedure is rolled back after a two-step RACH procedure fails. Signaling diagram 300 includes UE 110 and gNB 120A.

[0031] In step 305, a two-step RACH procedure is triggered. In step 310, UE 110 transmits msgA to gNB 120A. UE 110 can operate a timer (e.g., msgB-ResponseWindow) related to the reception of msgB in response to the transmission of msgA. If the timer expires before msgB is received, UE 110 can be configured to retransmit msgA.

[0032] In this example, msgB is not received in response to msgA. Therefore, in 315, the timer expires. In 320, UE110 retransmits msgA to gNB 120A. Again, msgB is not received in response to msgA. Therefore, in 325, the timer (e.g., msgB-ResponseWindow) expires. In signaling diagram 300, this process of transmitting msgA and not receiving the corresponding msgB continues until the random access preamble of msgA has been transmitted a pre-configured maximum number of times as shown in 330 (e.g., msgA-TransMax).

[0033] When a two-step RACH procedure fails due to triggering msgA-TransMax, UE 110 can be configured to fall back to a four-step RACH procedure. In 335, UE 110 switches to a four-step RACH procedure. In 340, UE 110 transmits msg1 to gNB 120A according to the four-step RACH procedure. Subsequently, the four-step RACH procedure may fail, and UE 110 can attempt RACH procedures with different base stations, or it can... Figure 1 The signaling diagram 100 shows the execution of a four-step RACH procedure.

[0034] The exemplary implementation introduces techniques related to the transmission of msg1 in the four-step rollback RACH procedure. An example of this transmission is provided by... Figure 3The signaling diagram 300 is shown at 340. However, while these exemplary techniques may provide benefits to the type of scenario shown in the signaling diagram 300, the exemplary implementation is not limited to the scenario depicted in the signaling diagram 300. The exemplary implementation can be applied to any scenario in which the UE 110 performs a two-step RACH procedure on the target node and then a four-step RACH procedure on the same node.

[0035] Figure 4 A method 400 for configuring random access preamble transmission for a four-step RACH procedure is illustrated according to various exemplary embodiments. From the perspective of UE 110 and with reference to... Figure 3 The signaling diagram 300 in the 400 is described by method 400.

[0036] In 405, UE 110 performs a two-step RACH procedure. In 410, the two-step RACH procedure fails. Examples of two-step RACH procedure failure due to triggering msgA-TransMax are provided above in signaling diagrams 305-330 of 300. As will be described in more detail below, UE 110 can use the information associated with the failed two-step RACH procedure to configure a four-step RACH procedure.

[0037] Figure 5 Signaling diagram 500 illustrates an example of performing multiple msgA transmissions during a failed two-step RACH procedure, according to various exemplary embodiments. In this example, UE 110 transmits msgA six times (505-530) without receiving msgB as a response. In 535, a pre-configured maximum number of transmissions (e.g., msgA-TransMax) for the random access preamble to msgA is triggered. Figure 5 In the example, it can be assumed that each subsequent transmission of msgA is performed using different higher PRACH transmission powers. To illustrate the different PRACH transmission power parameters configured for each transmission 505-530, values ​​N1-N6 measured in decibels (dB) are provided. This example is not intended to limit the exemplary implementation in any way. Rather, it is provided merely to illustrate that during a failed two-step RACH procedure, UE 110 can transmit msgA multiple times each time using different PRACH transmission power parameter values.

[0038] Returning to method 400, in 415, UE 110 switches to the four-step RACH procedure. UE 110 can be configured to fall back to the four-step RACH procedure when the parameter msgA-TransMax is triggered or in response to any other appropriate condition.

[0039] In 420, UE 110 derives the PRACH transmission power of msg1 for a four-step RACH procedure based on the PRACH transmission power used during the failed two-step RACH procedure. Before discussing exemplary techniques, refer below... Figure 6 Provide an example of the traditional method.

[0040] Figure 6 Signaling diagram 600 illustrates an example of multiple transmissions of msg1 during a four-step RACH procedure. In this example, UE 110 transmits msg1 six times (605-630) without receiving msg2. At 635, a pre-configured maximum number of transmissions (e.g., msg1-TransMax) for the random access preamble of msg1 is triggered. Here, each subsequent transmission of msg1 is performed using a different higher PRACH transmission power. To illustrate the different PRACH transmission power parameters, each transmission (605-630) is labeled with values ​​M1-M6 measured in dB. This example is not intended to limit the exemplary implementation in any way. Rather, it is provided merely to illustrate that UE 110 can transmit msg1 multiple times each time during a four-step RACH procedure using a different PRACH transmission power.

[0041] To demonstrate the traditional method, consider Figure 6 M1-M6 is less than Figure 5 In scenario N6, under normal circumstances, when UE 110 switches to a four-step RACH procedure, UE 110 can be configured to perform multiple transmissions using a PRACH transmission power lower than that used for the most recent transmission msgA (e.g., 530). Since the PRACH transmission power N1-N6 used for 505-530 did not result in a response from gNB 120A, using lower PRACH transmission power parameters (e.g., M1-M6) for msg1 is unlikely to result in a response from gNB 120A. In other words, the conventional approach is inefficient because UE 110 is configured to utilize parameters for transmissions and retransmissions for msg1 that are unlikely to result in a response from the base station (e.g., msg2).

[0042] Returning to method 400, as described above, UE 110 can derive the PRACH transmission power for msg1 based on the transmission parameter values ​​used for the failed two-step RACH procedure. For example, UE 110 can calculate the initial random access preamble transmission power parameters for msg1 based on the transmission parameters of the most recently transmitted msgA. As mentioned above, msg1 can be transmitted on PRACH, and therefore, the transmission power of msg1 is similar to or the same as the PRACH transmission power. In contrast, since msgA includes both PRACH and PUSCH components, the total transmission power of msgA is greater than the PRACH transmission power of msgA.

[0043] MsgA transmission power can be expressed by the following equation: P MsgA =P PUSCH +P PRACH +n*(P ramping )

[0044] Parameter P PUSCH This indicates the transmission power of the msgA PUSCH payload. This parameter can be a function of the Physical Resource Block (PRB) size, Modulation and Coding Scheme (MCS), and path loss estimate. The PRB size, MCS, and path loss estimate can be provided by the network via RRC signaling or obtained by any other suitable means.

[0045] Parameter P PRACH This represents the PRACH transmission power of msgA. This parameter can be a function of various network parameters and path loss estimates. Parameter n can represent the number of transmission attempts for msgA (e.g., 0, 1...msgA-TransMax) and parameter P... ramping This indicates the power ramp or parameter defined by the network.

[0046] UE 110 can derive the msg1 transmission power using information associated with the most recently transmitted msgA. The msg1 transmission power can be expressed by the following equation: P MSG1 =P PRACH +n*(P ramping Under normal circumstances, P PRACH This can be configured by the network. An exemplary embodiment introduces a technique that enables UE 110 to derive PRACH transport power parameters for msg1, the PRACH transport power parameters being based on the actual performance of the two-step RACH procedure.

[0047] UE 110 can be based on the P used for the most recently transmitted msgA. MsgA =P PUSCH +P PRACH +n*(P ramping To derive the P transmitted by msg1PRACH For example, UE 110 can obtain the P from the most recently transmitted msgA. MsgA Subtract the P of the most recently transmitted msgA PUSCH To export the initial transmission of msg1, P MSG1 For subsequent transmissions, P MSG1 It can be increased by the parameter n (e.g., the number of transmission attempts).

[0048] Figure 7 Signaling diagram 700 illustrates an example of deriving the PRACH transmit power parameter value of msg1 for a four-step RACH procedure based on the most recently transmitted msgA. In 705, a two-step RACH procedure is triggered. In 710-735, UE 110 transmits msgA, and in 740, the msgA-TransMax parameter is triggered. This is similar to... Figure 5 Signaling diagram 500.

[0049] To provide an example of how the PRACH transmission power of msg1 can be derived according to the exemplary techniques described herein, simplified example values ​​are shown for each transmission 710-735. These values ​​are not intended to limit the exemplary implementation in any way and are provided only to illustrate the relationship between a failed two-step RACH procedure and a backtracking four-step RACH procedure.

[0050] As mentioned above, P MsqA =P PUSCH +P PRACH +n*(P ramping For each transmission 710-735, P PUSCH It can be equal to 3dB and P PRACH It can be equal to 1dB. Because n*(P ramping For each subsequent msgA transmission attempt, the P MsgA It can be enlarged.

[0051] In 745, UE 110 switches to a four-step RACH procedure. In 750, UE 110 uses the transmission power parameter P derived from the most recently transmitted msgA. MSG1 To transmit msg1. Therefore, in this example, P for message 750 MSG1 It transmits 735 P MsgA Subtract P PUSCH The value of . Therefore, instead of as in Figure 6 The traditional method described in the text uses P MSG1 The network allocation parameters, in an exemplary implementation, utilize P derived from the transmission parameters used for the transmission of msgA during the failed two-step RACH procedure. MSG1 Parameter value.

[0052] In step 755, UE 110 retransmits msg1. In this example, it is assumed that gNB 120A successfully received the transmission of msg1 in step 755. Therefore, in step 760, UE gNB 120A transmits RAR to UE 110. Then, the four-step RACH procedure can be performed as follows: Figure 1 The signaling is performed as shown in Figure 100.

[0053] In some scenarios, the maximum transmission power level (MTPL) can be reached during a two-step RACH procedure before the msgA-TransMax parameter is triggered. Therefore, UE 110 can perform multiple transmissions of msgA using the MTPL. In some implementations, UE 110 can fall back to a four-step RACH procedure after performing transmissions using the MTPL during a two-step RACH procedure and before the msgA-TransMax parameter is triggered. Therefore, UE 110 can omit or suppress one or more transmissions during a two-step RACH procedure. This can provide power-saving benefits to UE 110. Figure 8 An example of this is shown in signaling diagram 800.

[0054] Figure 8 Signaling diagram 800 illustrates an example of a four-step RACH procedure triggered by MTPL. Signaling diagram 800 includes UE 110 and gNB 120A.

[0055] In 805, a two-step RACH procedure is triggered. In 810-820, UE 110 transmits msgA using a transmission power less than MTPL.

[0056] In 825, UE 110 transmits msgA using MTPL. At this time, the msgA-TransMax parameter has not yet been triggered. For example, in this example, the msgA-TransMax parameter could be set to 6, but UE 110 only performs four transmissions 810-825. As mentioned above, in some implementations, UE 110 can transmit msgA using MTPL until the msgA-TransMax parameter has been triggered. An example of this is shown in signaling diagram 800, where UE 110 performs transmissions 825a and 825b using MTPL.

[0057] However, in 830, UE 110 executes transmission 825 using MTPL instead of waiting for the triggering of the msgA-TransMax parameter to initiate the four-step RACH procedure. Therefore, transmissions 825a and 825b can be omitted or suppressed by UE 110. This can provide additional power-saving benefits to UE 110, as UE 110 can avoid executing transmissions that are unlikely to result in a successful RACH procedure (e.g., transmissions 825a and 825b).

[0058] Figure 9 An exemplary network arrangement 900 according to various exemplary embodiments is illustrated. The exemplary network arrangement 900 includes a UE 110. Those skilled in the art will understand that the UE 110 can be any type of electronic component configured to communicate via a network, such as a mobile phone, tablet, desktop computer, smartphone, phablet, embedded device, wearable device, Internet of Things (IoT) device, etc. It should also be understood that a practical network arrangement can include any number of UEs used by any number of users. Therefore, for illustrative purposes, only an example with a single UE 110 is provided.

[0059] UE 110 can be configured to communicate with one or more networks. In the example of network configuration 100, the network with which UE 110 can wirelessly communicate is the 5G NR radio access network (RAN) 120. However, UE 110 can also communicate with other types of networks (e.g., 5G cloud RAN, next-generation RAN (NG-RAN), LTE RAN, legacy cellular networks, WLAN, etc.), and UE 110 can also communicate with the network via a wired connection. Regarding an exemplary implementation, UE 110 can establish a connection with 5G NR RAN 120. Therefore, UE 110 may have a 5G NR chipset to communicate with 5G NR RAN 120.

[0060] The 5G NR RAN 120 can be part of a cellular network that can be deployed by network operators (e.g., Verizon, AT&T, T-Mobile, etc.). The 5G NR RAN 120 may include, for example, nodes, cells, or base stations (e.g., Node B, eNodeB, HeNB, eNBS, gNB, gNodeB, macrocell base station, microcell base station, small cell base station, femtocell base station, etc.) configured to send and receive communication services from UEs equipped with appropriate cellular chipsets.

[0061] Those skilled in the art will understand that any relevant procedures can be performed for UE 110 to connect to 5G NR-RAN 120. For example, as described above, 5G NR-RAN 120 can be associated with a specific cellular provider, at which UE 110 and / or its user have protocol and credential information (e.g., stored on a SIM card). Upon detecting the presence of 5G NR-RAN 120, UE 110 can transmit the corresponding credential information to associate with 5G NR-RAN 120. More specifically, UE 110 can be associated with a specific base station (e.g., next-generation Node B (gNB) 120A).

[0062] Network deployment 900 also includes a cellular core network 930, an Internet 940, an IP Multimedia Subsystem (IMS) 950, and a network services backbone 960. The cellular core network 930 can be viewed as an interconnected set of components that manage the operation and traffic of the cellular network. It may include an evolved packet core (EPC) and / or a 5G core (5GC). The cellular core network 930 also manages the traffic flowing between the cellular network and the Internet 940. The IMS 950 can generally be described as an architecture for delivering multimedia services to the UE 110 using IP protocols. The IMS 950 can communicate with the cellular core network 930 and the Internet 940 to provide multimedia services to the UE 110. The network services backbone 960 communicates directly or indirectly with the Internet 940 and the cellular core network 930. The network services backbone 960 can generally be described as a set of components (e.g., servers, network storage deployments, etc.) that implement a set of services that can be used to extend the functionality of the UE 110 to communicate with various networks.

[0063] Figure 10 An exemplary UE 110 according to various exemplary embodiments is shown. Reference will be made to... Figure 9 The network layout 900 is used to describe UE 110. UE 110 may include a processor 1005, a memory layout 1010, a display device 1015, an input / output (I / O) device 1020, a transceiver 1025, and other components 1030. The other components 1030 may include, for example, an audio input device, an audio output device, a power source, a data acquisition device, and ports for electrically connecting UE 110 to other electronic devices.

[0064] Processor 905 may be configured to execute multiple engines of UE 110. For example, these engines may include fallback RACH engine 935. Fallback RACH engine 935 may perform various operations related to the fallback four-step RACH procedure, including but not limited to receiving configuration information, deriving the transmission power parameters for msg1, and triggering a switch from a two-step RACH procedure to a four-step RACH procedure.

[0065] The engine 935 described above is provided as an application (e.g., a program) executed by the processor 905 for illustrative purposes only. The functionality associated with the engine 935 may also be represented as a separate, integrated component of the UE 110, or as a modular component coupled to the UE 110, such as an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. The engine may also be embodied as a single application or multiple separate applications. Furthermore, in some UEs, the functionality described for the processor 905 is split among two or more processors, such as a baseband processor and an application processor. Exemplary implementations may be implemented according to any of these or other configurations of the UE.

[0066] Memory arrangement 910 may be a hardware component configured to store data related to operations performed by UE 110. Display device 915 may be a hardware component configured to display data to a user, while I / O device 1020 may be a hardware component enabling user input. Display device 1015 and I / O device 1020 may be separate components or may be integrated together (such as a touchscreen). Transceiver 1025 may be a hardware component configured to establish connections with 5G NR-RAN 120, LTE-RAN (not shown), legacy RAN (not shown), WLAN (not shown), etc. Therefore, transceiver 1025 may operate on multiple different frequencies or channels (e.g., a set of consecutive frequencies).

[0067] Figure 11 An exemplary base station 1100 according to various exemplary embodiments is shown. Base station 1100 may represent a gNB 120A or any other type of access node that UE 110 can use to establish connections and manage network operations.

[0068] Base station 1100 may include processor 1105, memory arrangement 1110, input / output (I / O) devices 1115, transceiver 1120, and other components 1125. These other components 1125 may include, for example, audio input devices, audio output devices, batteries, data acquisition devices, ports for electrically connecting base station 1100 to other electronic devices, etc.

[0069] The processor 1105 can be configured to execute multiple engines of the base station 1100. For example, the engines may include a RACH engine 1130. The RACH engine 1130 can perform various operations related to two-step RACH and four-step RACH procedures.

[0070] The engine 1130 described above, as an application (e.g., a program) executed by the processor 1105, is merely exemplary. Functionality associated with the engine 1130 may also be represented as a separate integrated component of the base station 1100, or as a modular component coupled to the base station 1100, such as an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry for receiving signals and processing circuitry for processing signals and other information. Furthermore, in some base stations, the functionality described for the processor 1105 is distributed among multiple processors (e.g., a baseband processor, an application processor, etc.). Exemplary implementations can be implemented according to any of these or other configurations of the base station.

[0071] Memory 1110 may be a hardware component configured to store data related to operations performed by base station 1100. I / O device 1115 may be a hardware component or port enabling a user to interact with base station 1100. Transceiver 1120 may be a hardware component configured to exchange data with UE 110 and any other UE in network arrangement 900. Transceiver 1120 may operate on various frequencies or channels (e.g., a set of consecutive frequencies). Therefore, transceiver 1120 may include one or more components (e.g., radio components) capable of exchanging data with various networks and UEs.

[0072] Those skilled in the art will understand that the exemplary embodiments described above can be implemented with any suitable software or hardware configuration or combination thereof. Exemplary hardware platforms for implementing the exemplary embodiments may include, for example, Intel x86-based platforms with compatible operating systems, Windows OS, Mac platforms and MAC OS, and mobile devices with operating systems such as iOS, Android, etc. Exemplary embodiments of the methods described above may be embodied as programs comprising lines of code stored on a non-transitory computer-readable storage medium, which, at compile time, can be executed on a processor or microprocessor.

[0073] Although this patent application describes various combinations of various embodiments, each with different features, those skilled in the art will understand that any feature of an embodiment can be combined with features of other embodiments or features that are not functionally or logically inconsistent with the operation or function of the device of the disclosed embodiment of the invention in any manner not explicitly denied.

[0074] As is widely recognized, the use of personally identifiable information should comply with privacy policies and practices that are generally accepted to meet or exceed industry or governmental requirements for protecting user privacy. Specifically, personally identifiable information data should be managed and processed to minimize the risk of unintentional or unauthorized access or use, and the nature of authorized use should be clearly explained to users.

[0075] It will be apparent to those skilled in the art that various modifications can be made to this disclosure without departing from its spirit or scope. Therefore, this disclosure is intended to cover all modifications and variations thereof, provided that such modifications and variations are within the scope of the appended claims and their equivalents.

Claims

1. A processor for a user equipment (UE), the processor being configured to perform operations including: Initiate the two-step random access channel (RACH) procedure to synchronize with the base station; After the two-step RACH procedure, initiate the four-step rollback RACH procedure; Configure random access preamble transmission for the four-step RACH procedure, wherein configuring the random access preamble transmission includes: deriving the physical random access channel (PRACH) transmission power parameter value for the first message msg1 of the four-step RACH procedure by subtracting the physical uplink shared channel (PUSCH) payload transmission power of the most recently transmitted msgA from the total transmission power of the most recently transmitted first message msgA in the two-step RACH procedure; as well as The random access preamble for the four-step RACH procedure is transmitted to the base station.

2. The processor according to claim 1, wherein the msgA includes a PRACH component and a physical uplink shared channel component.

3. The processor of claim 1, wherein the fallback four-step RACH procedure is triggered based on the use of the maximum transmission power level (MTPL) during the two-step RACH procedure, and wherein the fallback four-step RACH procedure occurs before the UE has performed a maximum number of transmissions during the two-step RACH procedure.

4. The processor of claim 1, wherein the UE suppresses one or more configured transmissions during the two-step RACH procedure.

5. A user equipment (UE), comprising: A transceiver configured to communicate with a base station; and A processor, communicatively coupled to the transceiver and configured to perform operations including: Initiate the two-step random access channel (RACH) procedure to synchronize with the base station; After the two-step RACH procedure, initiate the four-step rollback RACH procedure; Configure random access preamble transmission for the four-step RACH procedure, wherein configuring the random access preamble transmission includes: deriving the physical random access channel (PRACH) transmission power parameter value for the first message msg1 of the four-step RACH procedure by subtracting the physical uplink shared channel (PUSCH) payload transmission power of the most recently transmitted msgA from the total transmission power of the most recently transmitted first message msgA in the two-step RACH procedure; as well as The random access preamble for the four-step RACH procedure is transmitted to the base station.

6. The UE according to claim 5, wherein the msgA includes a PRACH component and a physical uplink shared channel component.

7. The UE of claim 5, wherein the fallback four-step RACH procedure is triggered based on the use of the maximum transmission power level (MTPL) during the two-step RACH procedure, and wherein the fallback four-step RACH procedure occurs before the UE has performed a maximum number of transmissions during the two-step RACH procedure.

8. The UE of claim 5, wherein the UE suppresses one or more configured transmissions during the two-step RACH procedure.

9. A method to be performed at a user equipment (UE), comprising: Initiate the two-step random access channel (RACH) procedure to synchronize with the base station; After the two-step RACH procedure, initiate the four-step rollback RACH procedure; Configure random access preamble transmission for the four-step RACH procedure, wherein configuring the random access preamble transmission includes: deriving the physical random access channel (PRACH) transmission power parameter value for the first message msg1 of the four-step RACH procedure by subtracting the physical uplink shared channel (PUSCH) payload transmission power of the most recently transmitted msgA from the total transmission power of the most recently transmitted first message msgA in the two-step RACH procedure; as well as The random access preamble for the four-step RACH procedure is transmitted to the base station.

10. The method of claim 9, wherein the msgA comprises a PRACH component and a physical uplink shared channel component.

11. The method of claim 9, wherein the fallback four-step RACH procedure is triggered based on the use of the maximum transmission power level (MTPL) during the two-step RACH procedure, and wherein the fallback four-step RACH procedure occurs before the UE has performed a maximum number of transmissions during the two-step RACH procedure.

12. The method of claim 9, wherein the UE suppresses one or more configured transmissions during the two-step RACH procedure.

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