Performing a random access procedure in a wireless communication system

Abstract

Disclosed are methods including initiating a random access (RA) procedure with synchronization reconfiguration for a bandwidth part (BWP), initiating a synchronization reconfiguration using a low layer triggered mobility (LTM) candidate configuration to resume, when the BWP is configured with dedicated contention-free RA resources for 4-step RA, performing 4-step RA, when the BWP is not configured with dedicated contention-free RA resources for 4-step RA: when the BWP is configured with dedicated contention-free RA resources for 2-step RA, performing 2-step RA, when the BWP is not configured with dedicated contention-free RA resources for 2-step RA, performing 4-step RA; initiating a synchronization reconfiguration using an LTM candidate configuration to resume, when the BWP is configured with RA resources for 2-step RA: when the BWP is not configured with RA resources for 4-step RA, performing 2-step RA, when the BWP is configured with RA resources for 4-step RA: when the measured RSRP of the downlink pathloss reference is above the MsgA threshold, performing 2-step RA, and when the measured RSRP of the downlink pathloss reference is not above the MsgA threshold, performing 4-step RA.

Description

Technical Field

[0001] This disclosure generally relates to performing random access procedures. Background Technology

[0002] With the development of wireless systems, there are increasingly more scenarios where performing random access (RA) procedures for user equipment (UE) is desirable. However, many scenarios involving random access procedures have different requirements and priorities. Furthermore, there are various methods for performing random access, such as 2-step RA procedures, 4-step RA procedures, contention-based RA procedures, and contention-free RA procedures. For the UE, it is important to be able to select the correct type of RA procedure and the correct resources for the RA procedure based on the purpose of initiating the RA procedure. Summary of the Invention

[0003] Various aspects of the invention are set forth in the claims.

[0004] One or more embodiments may provide an apparatus, a computer-readable medium, a non-transitory computer-readable medium, a computer program product, and / or a method for initiating a random access (RA) procedure via a synchronized reconfiguration for a bandwidth portion (BWP), determining whether to use a lower-layer triggered mobility (LTM) candidate to initiate a synchronized reconfiguration for recovery when not using an LTM candidate configuration, determining whether the BWP is configured with dedicated, contention-free RA resources for a 4-step RA type, and performing a 4-step RA if the BWP is configured with dedicated, contention-free RA resources for a 4-step RA type, and performing a 2-step RA if the active BWP is not configured with dedicated, contention-free RA resources for a 4-step RA type. If the BWP is not configured with a dedicated, contention-free RA resource for the 2-step RA type, perform a 4-step RA. If a synchronized reconfiguration is initiated using an LTM candidate configuration for recovery: determine if the BWP is configured with RA resources for the 2-step RA type. If the BWP is configured with RA resources for the 2-step RA type, determine if the BWP is configured with RA resources for the 4-step RA type. If the BWP is not configured with RA resources for 4-step RA type random access, perform a 2-step RA. If the BWP is configured with RA resources for the 4-step RA type, determine if the measured reference received power (RSRP) of the downlink path loss reference is higher than the message A threshold. If the measured RSRP of the downlink path loss reference is higher than the message A threshold, perform a 2-step RA. If the measured RSRP of the downlink path loss reference is not higher than the message A threshold, perform a 4-step RA.

[0005] In at least one example embodiment, a dedicated, non-contested RA resource is received in the rach-configDedicated information element.

[0006] In at least one example embodiment, determining whether a BWP is configured with RA resources for a 2-step RA type includes determining whether a BWP is configured with public RA resources for a 2-step RA type.

[0007] In at least one example embodiment, determining whether a BWP is configured with RA resources for a 4-step RA type includes determining whether a BWP is configured with public RA resources for a 4-step RA type.

[0008] In at least one example embodiment, the scenario initiating a synchronous reconfiguration for recovery using an LTM candidate configuration includes a scenario where a previous synchronous reconfiguration failed and the UE is configured with a stored conditional RRC reconfiguration associated with the LTM candidate configuration.

[0009] In at least one example embodiment, performing a 2-step RA includes setting the RA type to be performed as a 2-step RA type and performing the RA process based on the set RA type.

[0010] In at least one example embodiment, performing a two-step RA includes selecting a set of RA resources and performing the RA process based on the RA type specified by the selected set of RA resources.

[0011] In at least one example embodiment, performing a 4-step RA includes setting the RA type to be performed as a 4-step RA type and performing the RA process based on the set RA type.

[0012] In at least one example embodiment, performing a 4-step RA includes selecting a set of RA resources and performing the RA process based on the RA type specified by the selected set of RA resources.

[0013] One or more embodiments may provide an apparatus, a computer-readable medium, a non-transitory computer-readable medium, a computer program product, and / or a method for initiating a random access (RA) procedure for a bandwidth portion (BWP), determining whether the RA procedure is initiated by a PDCCH command, and if the RA procedure is initiated by a PDCCH command, performing a 4-step RA using the RA resources indicated by the PDCCH command; if the RA procedure is not initiated by a PDCCH command: determining that the RA procedure is initiated by a synchronized reconfiguration, determining whether a low-layer triggered mobility (LTM) candidate is used to initiate a synchronized reconfiguration for recovery, and if an LTM candidate configuration is not used to initiate a synchronized reconfiguration for recovery: determining whether the BWP is configured with dedicated, contention-free RA resources for the 4-step RA type, performing a 4-step RA if the BWP is configured with dedicated, contention-free RA resources for the 4-step RA type; and if the active BWP is not configured with dedicated, contention-free RA resources for the 4-step RA type: determining whether the BWP is configured with resources for the 2-step RA type. Dedicated contention-free RA resources: If the BWP is configured with dedicated contention-free RA resources for 2-step RA type, perform 2-step RA; if the BWP is not configured with dedicated contention-free RA resources for 2-step RA type, perform 4-step RA. In the case of initiating a synchronized reconfiguration for recovery using LTM candidate configuration: determine if the BWP is configured with RA resources for 2-step RA type; if the BWP is configured with RA resources for 2-step RA type, determine if the BWP is configured with RA resources for 4-step RA type; if the BWP is not configured with RA resources for 4-step RA type random access, perform 2-step RA; if the BWP is configured with RA resources for 4-step RA type, determine if the measured reference received power (RSRP) of the downlink path loss reference is higher than the message A threshold; if the measured RSRP of the downlink path loss reference is higher than the message A threshold, perform 2-step RA; and if the measured RSRP of the downlink path loss reference is not higher than the message A threshold, perform 4-step RA.

[0014] In at least one example embodiment, the PDCCH command is a downlink control information (DCI).

[0015] In at least one example embodiment, the downlink control information is a DCI scrambled with a cell radio network temporary identifier (C-RNTI), and the DCI includes a frequency domain resource allocation field with each bit set to a value of 1.

[0016] In at least one exemplary embodiment, scrambling the DCI with C-RNTI and setting each bit to a value of 1 in the frequency domain allocation field symbolizes that the DCI is initiating the RA process via the PDCCH command.

[0017] In at least one example embodiment, the DCI includes a cell indicator field.

[0018] In at least one example embodiment, the DCI is DCI format 1_0.

[0019] In at least one example embodiment, when the RA procedure is initiated by a PDCCH command, performing a 4-step RA using the RA resources indicated by the PDCCH command includes: selecting a set of RA resources configured in the early uplink synchronization configuration, the set of RA resources corresponding to the cell indicated by the cell indicator field, and performing a 4-step RA includes performing a 4-step RA using the selected RA resources.

[0020] One or more embodiments may provide an apparatus, a computer-readable medium, a non-transitory computer-readable medium, a computer program product, and / or a method for initiating a random access (RA) procedure for a bandwidth portion (BWP), determining whether the RA procedure was initiated by a synchronized reconfiguration, and if so: determining whether a synchronized reconfiguration for recovery was initiated using a lower-layer triggered mobility (LTM) candidate; if not, determining whether the BWP is configured with a dedicated, contention-free RA resource for a 4-step RA type, and if so, performing a 4-step RA; if the active BWP is not configured with a dedicated, contention-free RA resource for a 4-step RA type, determining whether the BWP is configured with a dedicated, contention-free RA resource for a 2-step RA type, and if so, performing a 2-step RA; if not, the BWP is not configured with a dedicated, contention-free RA resource for a 2-step RA type. In the case of dedicated, uncontested RA resources, a 4-step RA is performed. When a synchronized reconfiguration is initiated using an LTM candidate configuration for recovery: It is determined whether the BWP is configured with RA resources for a 2-step RA type. If the BWP is configured with RA resources for a 2-step RA type: It is determined whether the BWP is configured with RA resources for a 4-step RA type. If the BWP is not configured with RA resources for 4-step RA type random access, a 2-step RA is performed. If the BWP is configured with RA resources for a 4-step RA type: It is determined whether the measured reference received power (RSRP) of the downlink path loss reference is higher than the message A threshold. If the measured RSRP of the downlink path loss reference is higher than the message A threshold, a 2-step RA is performed. If the measured RSRP of the downlink path loss reference is not higher than the message A threshold, a 4-step RA is performed. In cases where the RA procedure is not initiated by a synchronized reconfiguration: It is determined that the RA procedure is initiated by the LTM cell handover media access control (MAC) element (CE), and the LTM cell handover MAC element is determined. Whether the CE indicates contention-free random access resources: If the LTM cell handover MAC CE indicates contention-free random access resources, perform a 4-step RA using the contention-free resources indicated by the LTM cell handover MAC CE. If the LTM cell handover MAC CE does not indicate contention-free random access resources: Determine whether the BWP is configured with RA resources for a 2-step RA type. If the BWP is configured with RA resources for a 2-step RA type: Determine whether the BWP is configured with RA resources for a 4-step RA type. If the BWP is not configured with RA resources for a 4-step RA type random access, perform a 2-step RA.When the BWP is configured with RA resources for a 4-step RA type: It is determined whether the measured Reference Received Power (RSRP) of the downlink path loss reference is higher than the message A threshold. If the measured RSRP of the downlink path loss reference is higher than the message A threshold, a 2-step RA is performed; and if the measured RSRP of the downlink path loss reference is not higher than the message A threshold, a 4-step RA is performed.

[0021] One or more embodiments may provide an apparatus, a computer-readable medium, a non-transitory computer-readable medium, a computer program product, and / or a method for initiating a random access (RA) procedure for a bandwidth portion (BWP), determining whether the RA procedure is initiated by a PDCCH command, and if the RA procedure is initiated by a PDCCH command, performing a 4-step RA using the RA resources indicated by the PDCCH command; and if the RA procedure is not initiated by a PDCCH command: determining whether the RA procedure is initiated by a reconfiguration with synchronization, and if the RA procedure is initiated by a reconfiguration with synchronization: Determine whether a synchronized reconfiguration for recovery was initiated using a Low-Level Triggered Mobility (LTM) candidate configuration. If no synchronized reconfiguration for recovery was initiated using an LTM candidate configuration: Determine whether the BWP is configured with a dedicated, uncontested RA resource for the 4-step RA type. If the BWP is configured with a dedicated, uncontested RA resource for the 4-step RA type, execute the 4-step RA. If the active BWP is not configured with a dedicated, uncontested RA resource for the 4-step RA type: Determine whether the BWP is configured with a dedicated, uncontested RA resource for the 2-step RA type. If the BWP is configured with a dedicated, uncontested RA resource for the 2-step RA type... In the case of a dedicated, non-contact RA resource of type A, perform a 2-step RA. If the BWP is not configured with a dedicated, non-contact RA resource for type 2 RA, perform a 4-step RA. If a synchronous reconfiguration for recovery is initiated using an LTM candidate configuration: determine if the BWP is configured with a RA resource for type 2 RA. If the BWP is configured with a RA resource for type 2 RA: determine if the BWP is configured with a RA resource for type 4 RA. If the BWP is not configured with a RA resource for type 4 RA random access, perform a 2-step RA. When RA resources for a 4-step RA type are configured: Determine if the measured Reference Received Power (RSRP) of the downlink path loss reference is higher than the message A threshold. If the measured RSRP of the downlink path loss reference is higher than the message A threshold, perform a 2-step RA. If the measured RSRP of the downlink path loss reference is not higher than the message A threshold, perform a 4-step RA. When the RA procedure is not initiated by a synchronized reconfiguration: Determine if the RA procedure is initiated by the LTM cell handover media access control (MAC) element (CE). Determine if the LTM cell handover MAC CE indicates contention-free random access resources. If the LTM cell handover MAC CE indicates contention-free random access resources, perform a 4-step RA using the contention-free resources indicated by the LTM cell handover MAC CE. If the LTM cell handover MAC CE does not indicate contention-free random access resources: Determine if the BWP is configured with RA resources for a 2-step RA type.When the BWP is configured with RA resources for 2-step RA type: determine whether the BWP is configured with RA resources for 4-step RA type. If the BWP is not configured with RA resources for 4-step RA type random access, perform 2-step RA. When the BWP is configured with RA resources for 4-step RA type: determine whether the measured Reference Received Power (RSRP) of the downlink path loss reference is higher than the message A threshold. If the measured RSRP of the downlink path loss reference is higher than the message A threshold, perform 2-step RA; and if the measured RSRP of the downlink path loss reference is not higher than the message A threshold, perform 4-step RA. Attached Figure Description

[0022] To gain a more complete understanding of the embodiments of the present invention, reference is now made to the following description in conjunction with the accompanying drawings, in which:

[0023] Figure 1 This is a block diagram illustrating an apparatus according to at least one example embodiment.

[0024] Figure 2 This is a block diagram illustrating a wireless communication system according to at least one example embodiment.

[0025] Figure 3 This is a diagram illustrating a protocol stack according to at least one example embodiment.

[0026] Figures 4A-4B This is a diagram illustrating a random access procedure according to at least one example embodiment.

[0027] Figures 5A-5B It is a flowchart illustrating activities associated with performing random access according to at least one example embodiment, and

[0028] Figures 6-10 It is a flowchart illustrating the activities associated with the random access procedure according to at least one example embodiment. Detailed Implementation

[0029] By referring to the attached figures Figures 1 to 10 This will allow you to understand the embodiments of the present invention and its potential advantages.

[0030] Some embodiments will be described more fully below with reference to the accompanying drawings, which illustrate some, but not all, embodiments. Various embodiments of the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Similar reference numerals always refer to similar elements. As used herein, the terms “data,” “content,” “information,” and similar terms are used interchangeably to refer to data capable of being transmitted, received, and / or stored according to embodiments of the invention. Therefore, any use of such terms should not be considered as limiting the spirit and scope of the embodiments of the invention.

[0031] Additionally, as used herein, the term "circuit" refers to (a) a hardware circuit implementation only (e.g., an implementation in analog and / or digital circuitry); (b) a combination of a circuit and one or more computer program products, the computer program products comprising software and / or firmware instructions stored on one or more computer-readable storage media that work together to enable a device to perform one or more functions described herein; and (c) a circuit, such as, for example, one or more microprocessors or a portion thereof, which requires software or firmware for operation, even if the software or firmware is not physically present. This definition of "circuit" applies to all uses of the term herein, including in any claim. As another example, as used herein, the term "circuit" also includes implementations comprising one or more processors and / or portions thereof, along with accompanying software and / or firmware. As yet another example, the term "circuit" as used herein also includes, for example, baseband integrated circuits or application processor integrated circuits for mobile phones, or similar integrated circuits in servers, cellular network devices, other network devices, and / or other computing devices.

[0032] As defined herein, “non-transitory computer-readable medium” refers to physical media (e.g., volatile or non-volatile memory devices) and can be distinguished from “transitory computer-readable medium” which refers to electromagnetic signals.

[0033] Figure 1This is a block diagram illustrating an apparatus (such as electronic device 100) according to at least one example embodiment. However, it should be understood that the illustrated and described electronic device is merely an illustration of electronic devices from which embodiments of the invention may benefit, and therefore should not be construed as limiting the scope of the invention. While electronic device 100 is illustrated and will be described below for illustrative purposes, other types of electronic devices can readily employ embodiments of the invention. Electronic device 100 may be a network node (such as a user equipment (UE) or base station), and / or may be a personal digital assistant (PDA), pager, mobile computer, desktop computer, television, gaming device, laptop computer, tablet computer, media player, camera, video recorder, mobile phone, global positioning system (GPS) device, automobile, telephone booth, electronic table, and / or any other type of electronic system. Furthermore, the apparatus of at least one example embodiment need not be the entire electronic device, but may be a component or group of components of the electronic device in other example embodiments. For example, the apparatus may be an integrated circuit, an integrated circuit assembly, and / or the like.

[0034] Furthermore, the device can readily employ embodiments of the invention, regardless of its intended purpose of providing mobility. In this respect, while embodiments of the invention can be described in conjunction with mobile applications, it should be understood that embodiments of the invention can be utilized in conjunction with a wide variety of other applications both within and outside the mobile communications industry. For example, the device can be at least part of a non-portable device (such as a large-screen television, electronic table, telephone booth, car, and / or the like).

[0035] In at least one example embodiment, electronic device 100 includes a processor 110 and a memory 140. The processor 110 can be any type of processor, controller, embedded controller, processor core, and / or the like. In at least one example embodiment, the processor 110 utilizes computer program code to cause the device to perform one or more actions. The memory 140 may include volatile memory, such as volatile random access memory (RAM) including a cache area for temporary data storage, and / or other memory, such as non-volatile memory, which may be embedded and / or removable. Non-volatile memory may include EEPROM, flash memory, and / or the like. The memory 140 may store any one of several pieces of information as well as data. Electronic device 100 can use this information and data to implement one or more functions of electronic device 100, such as the functions described herein. In at least one example embodiment, the memory 140 includes computer program code such that the memory and the computer program code are configured to work with the processor to cause the device to perform one or more actions described herein.

[0036] The electronic device 100 may also include a transceiver 120. In at least one example embodiment, the transceiver 120 is coupled to one or more antennas 130. In at least one example embodiment, the processor 110 provides signals to and / or receives signals from the transceiver 120. The signals may include signaling information according to a communication interface standard, user voice, received data, user-generated data, and / or the like. The transceiver 120 may operate using one or more air interface standards, communication protocols, modulation types, and access types. By way of description, the electronic transceiver 120 may operate according to second-generation (2G) wireless communication protocols such as IS-136 (Time Division Multiple Access (TDMA)), Global System for Mobile Communications (GSM) and IS-95 (Code Division Multiple Access (CDMA)), according to third-generation (3G) wireless communication protocols such as Universal Mobile Telecommunications System (UMTS), CDMA2000, Wideband CDMA (WCDMA) and Time Division Synchronous CDMA (TD-SCDMA), and / or according to fourth-generation (4G) wireless communication protocols such as LTE, fifth-generation (5G) protocols such as New Radio (NR) wireless networking protocols (such as 802.11), short-range wireless protocols (such as Bluetooth) and / or the like.

[0037] Processor 110 may include components (such as circuitry) for implementing audio, video, communication, navigation, logic functions, and / or the like, as well as for implementing embodiments of the invention, including one or more functions as described herein. For example, processor 110 may include components such as digital signal processor devices, microprocessor devices, various analog-to-digital converters, digital-to-analog converters, processing circuitry, and other support circuitry for performing various functions, including one or more functions as described herein. The device can perform control and signal processing functions of electronic device 100 between these devices according to their respective capabilities. Therefore, processor 110 may include the ability to encode and interleave messages and data before modulation and transmission. Processor 110 may additionally include an internal voice encoder and may include an internal data modem. Further, processor 110 may include the ability to operate one or more software programs, which may be stored in memory and, among other things, enable processor 110 to implement at least a portion of an embodiment, including one or more functions as described herein. For example, processor 110 may operate connectivity programs, such as a conventional internet browser. For example, connectivity protocols may allow electronic device 100 to transmit and receive Internet content, such as location-based content and / or other web page content, according to Transmission Control Protocol (TCP), Internet Protocol (IP), User Datagram Protocol (UDP), Internet Message Access Protocol (IMAP), Post Office Protocol (POP), Simple Mail Transfer Protocol (SMTP), Wireless Application Protocol (WAP), Hypertext Transfer Protocol (HTTP), and / or the like.

[0038] Electronic device 100 may include a user interface for providing output and / or receiving input. Electronic device 100 may include output devices, such as audio output devices (e.g., ringers, headphones, speakers), tactile output devices (e.g., vibration transducers, electronically deformable surfaces, electronically deformable structures), and visual output devices (e.g., displays and / or lights). Electronic device may include input devices, such as light sensors, proximity sensors, microphones, touch sensors, force sensors, buttons, keyboards, motion sensors, magnetic field sensors, cameras, and / or the like. In at least one example embodiment, the device receives an indication of input. The device may receive the indication from sensors, drivers, separate devices, and / or the like. The information indicating the input may include information conveying: the indication of input, the aspect of the indication of input, the occurrence of the indication of input, and / or the like.

[0039] Figure 2An example of a wireless communication system 200 according to at least one exemplary embodiment is illustrated. The wireless communication system 200 includes one or more base stations 202, a core network 203, and one or more user equipments (UEs), such as UE 201 and / or UE 204. In some examples, the wireless communication system 200 may be a Long Term Evolution (LTE), LTE-Advanced (LTE-A) network, a New Radio (NR) network, etc. In some cases, the wireless communication system 200 may support enhanced broadband communication, ultra-reliable (i.e., mission-critical) communication, low-latency communication, and communication with low-cost and low-complexity devices. To improve the reliability of some communications (e.g., ultra-reliable low-latency communication (URLLC) packets), the wireless communication system 200 may be configured to generate and transmit duplicate packets. In such a duplication system, a transmission device (e.g., base station 202, UE 201, or UE 204) may duplicate packets. The original packets and the duplicated packets may be transmitted to a receiving device (e.g., base station 202, UE 201, or UE 204). Transmitting multiple packets containing the same information can improve the likelihood that the receiving device will receive information included in multiple packets.

[0040] One or more base stations 202 can wirelessly communicate with one or more UEs (e.g., UE 201 or UE 204) via one or more base station antennas. Each base station 202 can provide communication coverage for a corresponding geographical coverage area. The communication link in the wireless communication system 200 can include uplink transmission from the UE to the base station 202, or downlink transmission from the base station 202 to the UE. Depending on various technologies, control information and data can be multiplexed on the uplink channel or the downlink channel. For example, time division multiplexing (TDM), frequency division multiplexing (FDM), or hybrid TDM-FDM technologies can be used to multiplex control information and data on the downlink channel. In some examples, control information transmitted during the transmission time interval (TTI) of the downlink channel can be distributed in a cascaded manner between different control areas (e.g., between a common control area and one or more UE-specific control areas).

[0041] A wireless communication system 200 can be distributed across multiple UEs, each of which can be fixed or mobile. A UE can also be referred to as a mobile station, user station, mobile unit, user unit, radio unit, remote unit, mobile device, radio device, wireless communication device, remote device, mobile user station, access terminal, mobile terminal, radio terminal, remote terminal, mobile phone, user agent, mobile client, client, or some other suitable terminology. A UE can also be a cellular phone, personal digital assistant (PDA), wireless modem, wireless communication device, handheld device, tablet computer, laptop computer, cordless phone, personal electronic device, handheld device, personal computer, wireless local loop (WLL) station, Internet of Things (IoT) device, Internet of Everything (IoE) device, machine-type communication (MTC) device, appliance, automobile, etc.

[0042] In some cases, a UE may also be able to communicate directly with other UEs using sidelink communication (e.g., using point-to-point (P2P) or device-to-device (D2D) protocols). For example, Figure 2 An example of such communication between UE 201 and UE 204 is provided. One or more UEs in a group utilizing sidelink communication may be within the cell's coverage area. Other UEs in such a group may be outside the cell's coverage area or otherwise unable to receive transmissions from base station 202. In some cases, a group of UEs communicating via sidelink communication may utilize a one-to-many (1:M) system, where each UE transmits to all other UEs in the group. In some cases, base station 202 facilitates the scheduling of resources for sidelink communication. In other cases, sidelink communication is implemented independently of base station 202.

[0043] In some cases, UE 204 can operate as a relay UE for UE 201. For example, instead of communicating directly with base station 202, UE 204 can be configured to operate as a relay, allowing UE 201 to communicate with base station 202 via communication directly through UE 204. For example, UE 204 can operate as a Layer 2 (L2) UE-to-Network (U2N) relay.

[0044] Some UEs, such as MTC or IoT devices, may be low-cost or low-complexity devices that provide automated communication between machines, i.e., machine-to-machine (M2M) communication. M2M or MTC can refer to data communication technologies that allow devices to communicate with each other or with base stations without human intervention. For example, M2M or MTC can refer to communication from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application, which can then utilize or present that information to humans interacting with the program or application. Some UEs can be designed to collect information or automate machine behavior. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, health monitoring, wildlife monitoring, weather and geological event monitoring, fleet management and tracking, remote security sensing, physical access control, and transaction-based service charging.

[0045] In some cases, MTC devices can operate using half-duplex (one-way) communication at reduced peak rates. MTC devices can also be configured to enter a power-saving "deep sleep" mode when not engaged in active communication. In some cases, MTC or IoT devices can be designed to support mission-critical functions, and the wireless communication system can be configured to provide ultra-reliable communication for these functions.

[0046] Base station 202 can communicate with core network 203 and one or more other base stations. For example, the base station can interface with core network 203 via a come-backlink (e.g., S1, etc.). Base stations can communicate with each other directly or indirectly (e.g., via core network 203) via other backlinks (e.g., X2, etc.). The base station can perform radio configuration and scheduling for communicating with the UE, or can operate under the control of a base station controller (not shown). In some examples, base station 202 can be a macro cell, small cell, hotspot, and / or the like. The base station can also be referred to as an evolved NodeB (NB), such as an eNB, gNB, and / or the like.

[0047] Base station 202 can be connected to core network 203 via the S1 interface. The core network can be an evolved packet core (EPC), which may include at least one mobility management entity (MME), at least one serving gateway (S-GW), and at least one packet data network (PDN) gateway (P-GW). The MME can be a control node handling signaling between UE 201 and the EPC. All user Internet Protocol (IP) packets can be transmitted through the S-GW, which itself can be connected to the P-GW. The P-GW can provide IP address allocation and other functions. The P-GW can be connected to network operator IP services. Operator IP services may include the Internet, intranet, IP Multimedia Subsystem (IMS), and packet handover (PS) streaming services.

[0048] Core network 203 can provide user authentication, access authorization, tracking, IP connectivity, and other access, routing, or mobility functions. At least some of the network devices (such as base station 202) may include sub-components such as access network entities, which may be examples of access node controllers (ANCs). Each access network entity can communicate with several UEs through several other access network transport entities, each of which may be an example of a smart wireless head or a transmit / receive point (TRP). In some configurations, the various functions of each access network entity or base station may be distributed across various network devices (e.g., wireless heads and access network controllers) or consolidated into a single network device (e.g., base station 202).

[0049] Wireless communication system 200 can operate in the ultra-high frequency (UHF) frequency band from 700 MHz to 2600 MHz (2.6 GHz), although some networks (e.g., wireless local area networks (WLANs)) can use frequencies up to 4 GHz. This band can also be called the decimeter band because the wavelengths range in length from approximately one decimeter to one meter. UHF waves may primarily propagate through the line of sight and may be blocked by buildings and environmental features. However, the waves can penetrate walls sufficiently to provide service to UEs located indoors. Compared to transmissions using smaller frequencies (and longer waves) in the high frequency (HF) or very high frequency (VHF) portions of the spectrum, UHF wave transmission is characterized by smaller antennas and shorter ranges (e.g., less than 100 km). In some cases, wireless communication system 200 may also utilize the extremely high frequency (EHF) portion of the spectrum (e.g., from 30 GHz to 300 GHz). This band can also be called the millimeter band because the wavelengths range in length from approximately one millimeter to one centimeter. Therefore, EHF antennas may be even smaller and more closely spaced than UHF antennas. In some cases, this can facilitate the use of antenna arrays within the UE 201 (e.g., for directional beamforming). However, compared to UHF transmission, EHF transmission may suffer from even greater atmospheric attenuation and a shorter range.

[0050] Therefore, the wireless communication system 200 can support millimeter-wave (mmW) communication between the UE and the base station. Devices operating in the mmW or EHF band can have multiple antennas to allow beamforming. That is, the base station 202 can use multiple antennas or antenna arrays to perform beamforming operations for directional communication with the UE 201. Beamforming (which can also be referred to as spatial filtering or directional transmission) is a signal processing technique that can be used at the transmitter (e.g., the base station) to shape and / or modulate the overall antenna beam in the direction of the target receiver (e.g., the UE). This can be achieved by combining elements in an antenna array in such a way that signals transmitted at a specific angle undergo constructive interference, while other signals undergo destructive interference.

[0051] A cell can operate within the total channel bandwidth. In some cases, it may be desirable for the cell to have a configuration that refers to different portions of the total channel bandwidth, such as a Bandwidth Part (BWP). Such a structure allows the cell's configuration information to be common within a BWP and different across different BWPs. For example, it may be desirable for a cell to have two BWPs, allowing time-frequency resources to be configured differently between the two BWPs. Furthermore, such a configuration allows for a smooth transition between configurations for a BWP and configurations for different BWPs simply by indexing the correct BWP and referencing the configuration information of the indexed BWP. In this way, each BWP can have its own configuration information for managing multiple aspects of communication, such as physical layer resources, MAC resources, RRC resources, etc.

[0052] Multiple-input multiple-output (MIMO) wireless systems use a transmission scheme between a transmitter (e.g., a base station) and a receiver (e.g., a UE), both of which are equipped with multiple antennas. Some portions of the wireless communication system 200 may use beamforming. For example, base station 202 may have an antenna array with several rows and columns of antenna ports, which the base station can use for beamforming in its communication with UE 201. Signals may be transmitted multiple times in different directions (e.g., each transmission may be beamformed differently). The mmW receiver (e.g., the UE) may attempt multiple beams (e.g., antenna subarrays) while receiving a synchronization signal.

[0053] In some cases, the antennas of base station 202 or UE 201 may be located within one or more antenna arrays, which can support beamforming or MIMO operation. One or more base station antennas or antenna arrays may be juxtaposed at an antenna assembly (such as an antenna tower). In some cases, the antennas or antenna arrays associated with base station 202 may be located in different geographical locations. Base station 202 may use multiple antennas or antenna arrays to perform beamforming operation for directional communication with UE 201.

[0054] In some cases, the wireless communication system 200 may be a packet-based network operating according to a layered protocol stack. In the user plane, communication at the bearer layer or PDCP layer may be IP-based. In some cases, the RLC layer may perform packet segmentation and reassembly for communication over logical channels. The Media Access Control (MAC) layer may perform priority processing and multiplexing logical channels into transport channels. The MAC layer may also use Hybrid Automatic Repeat Request (HARQ) to provide retransmissions at the MAC layer to improve link efficiency. In the control plane, the Radio Resource Control (RRC) protocol layer may provide the establishment, configuration, and maintenance of RRC connections between the UE 201 and the network equipment or core network 203 supporting user plane data radio bearers. At the physical (PHY) layer, transport channels may be mapped to physical channels.

[0055] In LTE or NR, time intervals can be expressed as multiples of the basic time unit (e.g., a sampling period of Ts = 1 / 30,720,000 seconds). Time resources can be organized into radio frames of 10 ms in length (Tf = 307200Ts), identified by System Frame Numbers (SFNs) ranging from 0 to 1023. Each frame can comprise ten 1 ms subframes numbered from zero to nine. Subframes can also be divided into two 0.5 ms slots, each containing six or seven modulation symbol periods (depending on the length of the cyclic prefix pre-added to each symbol). Each symbol contains 2048 sampling periods, excluding the cyclic prefix. In some cases, a subframe can be the smallest scheduling unit, also known as the Time Interval (TTI). In other cases, the TTI can be shorter than a subframe or can be dynamically selected (e.g., in short TTI bursts or in selected component carriers using short TTIs).

[0056] A resource element can consist of one symbol period and one subcarrier (e.g., a 15 kHz frequency range). A resource block can contain twelve consecutive subcarriers in the frequency domain, and for each normal cyclic prefix in an Orthogonal Frequency Division Multiplexing (OFDM) symbol, it can contain seven consecutive OFDM symbols (one timeslot), or 84 resource elements. The number of bits carried by each resource element can depend on the modulation scheme (the configuration of symbols selectable during each symbol period). Therefore, the more resource blocks the UE receives, and the more sophisticated the modulation scheme, the higher the data rate may be.

[0057] The wireless communication system 200 can support operation on multiple cells or carriers, a feature that can be referred to as carrier aggregation (CA) or multi-carrier operation. A carrier can also be referred to as a component carrier (CC), layer, channel, etc. The terms "carrier," "component carrier," "cell," and "channel" are used interchangeably herein. The UE 201 can be configured with multiple downlink CCs and one or more uplink CCs for carrier aggregation. Carrier aggregation can be used in conjunction with both frequency division duplex (FDD) component carriers and time division duplex (TDD) component carriers.

[0058] In some cases, wireless system 200 can utilize both licensed and unlicensed radio spectrum bands. For example, wireless system 200 can employ LTE Licensed Assisted Access (LTE-LAA) or LTE Unlicensed (LTE U) radio access technologies or NR technologies in unlicensed bands such as the 5 GHz Industrial, Scientific, and Medical (ISM) band. When operating in unlicensed radio spectrum bands, wireless devices such as base station 202 and UE 201 can employ a Listen-After-Talk (LBT) procedure to ensure that the channel is unoccupied before data transmission. In some cases, operation in unlicensed bands can be based on CA configuration combined with CC operation in licensed bands. Operation in unlicensed spectrum can include downlink transmission, uplink transmission, or both. Duplexing in unlicensed spectrum can be based on FDD, TDD, or a combination of both.

[0059] Figure 3 This is a diagram illustrating a protocol stack 300 according to at least one example embodiment. Figure 3 The examples provided are merely examples and do not necessarily limit the scope of the claims.

[0060] In at least one example embodiment, the physical (PHY) layer 304 provides information delivery services to higher layers using a physical channel. The PHY layer 304 may be connected to the media access control (MAC) layer 303 located at a higher layer via a transport channel. Data may be transmitted between the MAC layer 303 and the PHY layer 304 via the transport channel. Data may be transmitted between the physical layer on the transmitting side and the physical layer on the receiving side via the physical channel. The physical channel uses time and frequency as radio resources. In some cases, an orthogonal frequency division multiple access (OFDMA) scheme is used to modulate the physical channel in the downlink, and a single-carrier frequency division multiple access (SC-FDMA) scheme is used to modulate the physical channel in the uplink.

[0061] In at least one example embodiment, MAC layer 303 provides services to the higher-level Radio Link Control (RLC) layer 302 via a logical channel. The second-layer RLC layer 302 supports reliable data transmission. The functionality of RLC layer 302 can be implemented by function blocks of MAC layer 303. Packet Data Convergence Protocol (PDCP) layer 301 performs header compression to reduce unnecessary control information, enabling efficient transmission of Internet Protocol (IP) packets, such as IP version 4 (IPv4) or IP version 6 (IPv6) packets, over a radio interface with relatively small bandwidth.

[0062] In at least one exemplary embodiment, the PDCP layer 301 is implemented by PDCP entities performing various actions of the PDCP layer. In this manner, the operating network node includes one or more PDCP entities for performing PDCP layer activities. In operation, the PDCP entities receive data from higher layers in PDCP Service Data Units (SDUs) for transmission. The PDCP entities perform various operations on the PDCP SDUs received from higher layers for transmission, such as header compression, uplink data compression, integrity protection, encryption, and / or the like. The PDCP entities perform these operations on the received PDCP SDUs to generate PDCP Packet Data Units (PDUs), which are transmitted by the PDCP entities sending the PDCP SDUs to lower layers for transmission.

[0063] In at least one exemplary embodiment, the RLC layer 302 is implemented by RLC entities performing various actions of the RLC layer. In this manner, the operating network node includes one or more RLC entities for performing RLC layer activities. In operation, the RLC entities receive data from higher layers in RLC SDUs for transmission. The RLC entities perform various operations on the RLC SDUs received from higher layers for transmission, such as header compression, uplink data compression, integrity protection, encryption, and / or the like. The RLC entities perform these operations on the received RLC SDUs to generate RLC PDUs, which are then transmitted by the RLC entities sending the RLC SDUs to lower layers for transmission.

[0064] In at least one example embodiment, MAC layer 303 is implemented by MAC entities performing various MAC layer actions. In this way, the operating network node includes one or more MAC entities for performing MAC layer activities. In operation, the MAC entities receive data from higher layers in MAC SDUs for transmission. The MAC entities perform various operations on the MAC SDUs received from higher layers for transmission, such as header compression, uplink data compression, integrity protection, encryption, and / or the like. The MAC entities perform these operations on the received MAC SDUs to generate MAC PDUs, which are then transmitted by the MAC entities sending the MAC SDUs to lower layers for transmission.

[0065] In many cases, it may be desirable for a UE to use a random access procedure to initiate communication or synchronization with a base station. A UE can use a random access procedure to initiate communication or synchronization for various purposes. A UE can use contention-based random access or contention-free random access. In at least one example embodiment, contention-based random access refers to a random access procedure in which the UE uses resources shared across multiple UEs, making contention for the same resources possible. In this case, a contention resolution mechanism can be part of the random access procedure. In at least one example embodiment, contention-free random access refers to a random access procedure in which the UE uses resources dedicated to that UE. In this case, the random access procedure can avoid a contention resolution mechanism. In at least one example embodiment, random access resources can refer to any resources that a UE can configure to perform a random access procedure, such as one or more random access preambles, time-frequency resources for performing the random access procedure, etc.

[0066] In addition, there are two different types of random access procedures: the 4-step random access type and the 2-step random access type.

[0067] Figures 4A-4B This is a diagram illustrating a random access (RA) procedure according to at least one example embodiment. Figures 4A-4B The examples provided are merely examples and do not necessarily limit the scope of the claims.

[0068] Figure 4A This is a diagram illustrating a four-step random access process between UE 401 and base station 402 according to at least one example embodiment.

[0069] At communication 403, UE 401 sends message 1 to the base station. In at least one example embodiment, message 1 is a random access request. In at least one example embodiment, message 1 includes a random access preamble. In at least one example embodiment, message 1 is sent on the random access channel (RACH) using random access resources.

[0070] At communication 404, the UE receives message 2 from base station 402. In at least one example embodiment, message 2 is a random access response. In at least one example embodiment, the random access response indicates that the UE can use resources for the transmission of message 3.

[0071] At communication 405, the UE sends message 3 to base station 402 using the resources indicated by message 2. Message 3 may be referred to as data transmission. In at least one example embodiment, message 3 is transmitted using the Physical Uplink Shared Channel (PUSCH) using the PUSCH resources indicated by message 2.

[0072] At communication 406, the UE receives message 4 if necessary. In at least one example embodiment, message 4 is a contention resolution message. In this case, it is likely desirable for the UE to perform a two-step random access procedure.

[0073] In some cases, it may be desirable for the UE to perform the random access procedure with a reduced latency compared to a 4-step random access procedure.

[0074] Figure 4B This is a diagram illustrating a two-step random access process between UE 401 and base station 402 according to at least one example embodiment.

[0075] At communication 423, UE 401 sends message A to base station 402. In at least one example embodiment, message A includes a random access request and data transmission. In at least one example embodiment, message A includes an RA preamble transmitted on the RACH and data transmission on the PUSCH.

[0076] At communication 424, UE 401 receives message B from base station 402. In at least one example embodiment, message B includes a random access response and any necessary contention resolution messages.

[0077] While a 2-step RA procedure can reduce latency, initiating a 4-step RA procedure may be more reliable. Therefore, depending on the situation, a 2-step RA type is sometimes preferred over a 4-step RA type, and at other times a 4-step RA type may be preferred over a 2-step RA type. For example, in some cases, it may be desirable to measure the Reference Received Power (RSRP) of the downlink path loss reference to determine whether to initiate a 2-step RA type. In some cases, it may be desirable to condition the performance of the 2-step RA type procedure on the measured RSRP of the downlink path loss reference being greater than a configured message-A threshold. In at least one example embodiment, the UE measures the RSRP of the downlink path loss reference. In at least one example embodiment, the UE determines whether the measured RSRP of the downlink path loss reference is higher than the message-A threshold. In at least one example embodiment, the UE performs a 2-step RA if the measured RSRP of the downlink path loss reference is higher than the message-A threshold. In at least one example embodiment, the UE performs a 4-step RA if the measured RSRP of the downlink path loss reference is not higher than the message-A threshold.

[0078] In at least one example embodiment, the UE receives configuration information for performing the RA procedure. In at least one example embodiment, the UE receives BWP configuration information, which includes configuration information for performing the RA procedure. In this way, the configuration information for the RA procedure can be specific to a particular BWP. For example, the UE can receive BWP uplink configuration information that includes RA configuration information.

[0079] In at least one example embodiment, the BWP is configured with public RA resources and / or dedicated RA resources. In at least one example embodiment, the term public RA resource refers to resources that the UE can share with other UEs. For example, the UE may receive a BWP configuration that includes the configuration of RA resources in a public configuration information element, such as a RACH public configuration information element, a RACH 2-step RA public configuration element, and / or the like. Public RA resources may also be referred to as contention-based RA (CBRA) resources. In at least one example embodiment, the term dedicated RA resource refers to resources specifically allocated to the UE. For example, the UE may receive a BWP configuration that includes the configuration of RA resources in a dedicated configuration information element, such as a RACH dedicated configuration information element (e.g., a rach-configDedicated information element). Dedicated RA resources may also be referred to as contention-free RA (CFRA) resources, dedicated contention-free RA resources, and / or the like. In at least one example embodiment, where no other defining terms are present, the term RA resource refers to dedicated RA resources and / or public RA resources.

[0080] In at least one example embodiment, a 2-step RA resource is configured differently from a 4-step RA resource. The term "2-step RA resource" may refer to an RA resource used to perform a 2-step RA type. In at least one example embodiment, due to differences in the relevant parameters of each of these configurations, the information elements used to configure a 2-step RA resource differ from the information elements used to configure a 4-step RA resource. For example, a dedicated 4-step RA resource may be included in a CFRA information element, and a dedicated 2-step RA resource may be included in a 2-step SFRA information element. In another example, a common 4-step RA resource may be included in a common RACH configuration information element, and a common 2-step RA resource may be included in a common RACH 2-step configuration information element. In at least one example embodiment, without any other defining terms, the terms "4-step RA resource" and "RA resource for a 4-step RA type" refer to dedicated 4-step RA resources and / or common 4-step RA resources. In at least one example embodiment, without any other defining terms, the terms "2-step RA resource" and "RA resource for a 2-step RA type" refer to dedicated 2-step RA resources and / or common 2-step RA resources.

[0081] In at least one example embodiment, the RA resource configuration information includes parameters that specify a particular resource and parameters that manage the use of such resource. For example, the RA resource configuration information may include parameters that specify time-frequency resources, RA preambles, and / or the like. Furthermore, the 2-step RA resource configuration information may include threshold information, such as message A thresholds.

[0082] There are many reasons to initiate a random access procedure. For example, based on instructions from the base station, or as part of a reconfiguration, it may be desirable for the UE initiating data communication to perform a RA procedure for handover. In at least one example embodiment, reconfiguration refers to an RRC reconfiguration procedure used to establish a radio connection between the UE and the base station. In some cases, it may be desirable for the UE to perform a synchronous reconfiguration (also referred to as a synchronized reconfiguration). For example, a synchronized reconfiguration may be useful for handover, handling RRC reconfiguration failures, radio link failure recovery, and / or the like. In at least one example embodiment, the UE performs an RA procedure as part of a synchronized reconfiguration. In at least one example embodiment, the RA procedure is initiated by a synchronized reconfiguration. In such an example, the UE initiates an RA procedure to complete a synchronized reconfiguration procedure.

[0083] Synchronous reconfiguration can be initiated by the base station or by the UE. In at least one example embodiment, the UE receives an RRC reconfiguration message that includes an indication for performing a synchronous reconfiguration. In this way, the synchronous reconfiguration is initiated by the base station, and the UE performs the synchronous reconfiguration in response to receiving the RRC message. In some cases, it may be desirable for the UE to store configuration information that will be used for RRC reconfiguration in certain circumstances. For example, it may be desirable for the UE to use such configuration information to perform a synchronous reconfiguration in the event of an RRC reconfiguration failure, radio link failure, and / or the like. In at least one example embodiment, the UE receives conditional RRC reconfiguration information and stores the conditional RRC reconfiguration. In at least one example embodiment, in the event that a previous synchronous reconfiguration has failed, the UE uses the stored conditional RRC reconfiguration to perform a synchronous reconfiguration. In at least one example embodiment, the conditional RRC reconfiguration includes a cell candidate configuration for reconfiguration. In at least one example embodiment, if a previous synchronous reconfiguration fails and the UE is configured with a stored conditional RRC reconfiguration associated with a cell candidate configuration, the UE initiates a synchronous reconfiguration using the cell candidate configuration in order to recover.

[0084] Low-layer triggered mobility (LTM) uses low-layer signaling to perform reconfiguration while preserving the configuration of upper layers. In some cases, it is desirable for LTM to reduce latency and signaling overhead during reconfiguration. During LTM, the user plane can continue whenever possible without resetting, allowing candidate cells to avoid additional delays in data loss and data recovery. Furthermore, security updates can be avoided in LTM. In at least one example embodiment, LTM is used to perform a reconfiguration with synchronization. In at least one example embodiment, a cell candidate may indicate that the cell candidate supports LTM. In at least one example embodiment, an LTM candidate refers to a cell candidate configured for LTM. In at least one example embodiment, the UE uses a low-layer triggered mobility (LTM) candidate to initiate a reconfiguration with synchronization for recovery. In such an example, the RA procedure is initiated by a reconfiguration with synchronization using an LTM candidate.

[0085] The UE can configure a large number of RA resources for the BWP. When initiating an RA procedure, the UE must determine which type of RA to perform based on the RA resources configured for the BWP and the purpose of the RA procedure. In at least one example embodiment, the UE performs a specific type of RA procedure based on the RA resources configured for the BWP and the manner in which the RA procedure is initiated.

[0086] In some cases, depending on the reason for initiating the RA process, it may be desirable to prefer dedicated RA resources over public RA resources, public RA resources over dedicated RA resources, a 4-step RA type over a 2-step RA type, and a 2-step RA type and / or the like over a 4-step RA type. For example, when the RA process is initiated by a synchronous reconfiguration, it may be desirable to avoid the long latency associated with competing solutions to RA processes initiated by synchronous reconfiguration by prioritizing dedicated RA resources over public RA resources. Furthermore, when the RA process is initiated by a synchronous reconfiguration using dedicated RA resources, it may be desirable to prioritize reliability by prioritizing a 4-step RA type over a 2-step RA type. Conversely, when the RA process is initiated by a synchronous reconfiguration using public RA resources, it may be desirable to prioritize reducing overhead and latency by prioritizing a 2-step RA type over a 4-step RA type.

[0087] However, when using an LTM candidate configuration to initiate a synchronous reconfiguration for recovery, it might be desirable to use a different priority order. For example, in this case, it might be desirable to avoid using dedicated RA resources rather than prioritizing them. Therefore, determining which type of RA procedure to execute requires considering not only whether the RA procedure was initiated by a synchronous reconfiguration, but also whether a synchronous reconfiguration for recovery was initiated using an LTM candidate configuration.

[0088] After the UE applies the appropriate priority based on the way the RA procedure is initiated, the UE has several ways to execute the appropriate RA type procedure.

[0089] For example, each set of RA resources can have a different RA resource set identifier, which uniquely identifies the RA resource set of the BWP. In this case, it might be desirable to execute the RA type procedure by selecting the RA resource set identifier based on RA configuration information and the way the RA procedure is initiated, and then using the RA type associated with the RA resource set identifier to determine which RA type procedure to execute. This type of solution necessarily requires an RA resource set identifier. In this case, a uniform RA resource set structure might also be needed, which can include parameters for each different type of RA resource, such as dedicated RA resources, public RA resources, 2-step RA type resources, 4-step RA type resources, etc. In this way, each RA resource set can generally be indexed by an RA resource set identifier, which can be used to select and specify RA resource sets for use in RA procedures.

[0090] In another example, the UE can set the RA type of the RA procedure based on RA configuration information and the method of initiating the RA procedure, and then use the set RA type to determine which RA type procedure to execute. This type of operation may be desirable in the absence of an RA resource set identifier. For example, given the lack of an RA resource set identifier, it may be desirable to determine the applicable RA resource set each time specific parameters are required. This type of solution may be necessary when no RA resource set identifier is specified, or when there are multiple different information elements specifying the available RA resource set for BWP.

[0091] Figure 5A This is a flowchart illustrating activities associated with performing random access according to at least one example embodiment. In at least one example embodiment, there is a... Figure 5A The set of operations corresponding to the activities. Devices (e.g.) Figure 1 The electronic device 100, or a part of the device, can utilize this set of operations. The device may include components for performing such operations, including, for example... Figure 1 The processor 110. In an example embodiment, by enabling the memory (e.g. Figure 1 The memory 140 includes computer code to transform the device (e.g., Figure 1 Electronic device 100), the computer code is configured to work with a processor (e.g., Figure 1 The processor 110) works together to enable the device to perform Figure 5A The set of operations.

[0092] At box 501, the device sets the RA type. For example, the RA type can be set based on the RA configuration information for the BWP and the method of initiating the RA process.

[0093] At box 502, the device performs the RA procedure based on the set RA type. For example, if the set RA type is a 4-step RA type, the UE performs a 4-step RA procedure. In another example, if the set RA type is a 2-step RA type, the UE performs a 2-step RA procedure.

[0094] Figure 5B This is a flowchart illustrating activities associated with performing random access according to at least one example embodiment. In at least one example embodiment, there is a... Figure 5B The set of operations corresponding to the activities. Devices (e.g.) Figure 1 The electronic device 100, or a portion thereof, may utilize the set of operations. The device may include components for performing such operations, including, for example... Figure 1 The processor 110. In an example embodiment, by enabling the memory (e.g. Figure 1The memory 140 includes computer code to transform the device (e.g., Figure 1 Electronic device 100), the computer code is configured to work with a processor (e.g., Figure 1 The processor 110) works together to enable the device to perform Figure 5B The set of operations.

[0095] At box 521, the device selects the RA resource set. For example, the selection of the RA resource set can be based on the RA configuration information for the BWP and the method of initiating the RA process.

[0096] At box 522, the device performs the RA procedure based on the RA type included in the selected RA resource set. For example, if the selected RA resource set indicates that the RA resources are applied to a 2-step RA type, the UE performs a 2-step RA procedure. In another example, if the selected RA resource set indicates that the RA resources are applied to a 4-step RA type, the UE performs a 4-step RA procedure.

[0097] Figure 6 This is a flowchart illustrating activities associated with a random access procedure according to at least one example embodiment. In at least one example embodiment, there is a... Figure 6 The set of operations corresponding to the activities. Devices (e.g.) Figure 1 The electronic device 100, or a portion thereof, may utilize the set of operations. The device may include components for performing such operations, including, for example... Figure 1 The processor 110. In an example embodiment, by enabling the memory (e.g. Figure 1 The memory 140 includes computer code to transform the device (e.g., Figure 1 Electronic device 100), the computer code is configured to work with a processor (e.g., Figure 1 The processor 110) works together to enable the device to perform Figure 6 The set of operations.

[0098] At box 601, the device initiates the RA process for the BWP by reconfiguring with synchronization.

[0099] At block 602, the device determines whether a synchronous reconfiguration for recovery was initiated using an LTM candidate configuration. If a synchronous reconfiguration for recovery was not initiated using an LTM candidate configuration, the process proceeds to block 610. If a synchronous reconfiguration for recovery was initiated using an LTM candidate configuration, the process proceeds to block 603.

[0100] At block 603, the device determines whether the BWP is configured with RA resources for the 2-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 2-step RA type includes determining whether the BWP is configured with public RA resources for the 2-step RA type. If the BWP is configured with RA resources for the 2-step RA type, the process continues to block 604. If the BWP is not configured with RA resources for the 2-step RA type, the process continues to block 605.

[0101] At box 604, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0102] At block 605, the device determines whether the BWP is configured with RA resources for the 4-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 4-step RA type includes determining whether the BWP is configured with public RA resources for the 4-step RA type. If the BWP is not configured with RA resources for 4-step RA type random access, the process continues to block 609. If the BWP is configured with RA resources for the 4-step RA type, the process continues to block 606.

[0103] At block 606, the device determines whether the measured reference received power (RSRP) of the downlink path loss reference is higher than the message A threshold. If the measured RSRP of the downlink path loss reference is higher than the message A threshold, the procedure proceeds to block 607. If the measured RSRP of the downlink path loss reference is not higher than the message A threshold, the procedure proceeds to block 608.

[0104] At box 607, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0105] At box 608, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0106] At box 609, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0107] At block 610, the device determines whether the BWP is configured with a dedicated, contention-free RA resource for the 4-step RA type. If the BWP is configured with a dedicated, contention-free RA resource for the 4-step RA type, the process proceeds to block 611. If the active BWP is not configured with a dedicated, contention-free RA resource for the 4-step RA type, the process proceeds to block 612.

[0108] At box 611, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0109] At block 612, the device determines whether the BWP is configured with a dedicated, contention-free RA resource for the 2-step RA type. If the BWP is configured with a dedicated, contention-free RA resource for the 2-step RA type, the process proceeds to block 613. If the BWP is not configured with a dedicated, contention-free RA resource for the 2-step RA type, the process proceeds to block 614.

[0110] At box 613, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0111] At box 614, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0112] Figure 7 This is a flowchart illustrating activities associated with a random access procedure according to at least one example embodiment. In at least one example embodiment, there is a... Figure 7 The set of operations corresponding to the activities. Devices (e.g.) Figure 1 The electronic device 100, or a portion thereof, may utilize the set of operations. The device may include components for performing such operations, including, for example... Figure 1 The processor 110. In an example embodiment, by enabling the memory (e.g. Figure 1 The memory 140 includes computer code to transform the device (e.g., Figure 1 Electronic device 100), the computer code is configured to work with a processor (e.g., Figure 1 The processor 110) works together to enable the device to perform Figure 7 The set of operations.

[0113] At box 701, the device initiates the RA process for BWP by reconfiguring with synchronization.

[0114] At block 702, the device determines whether a synchronous reconfiguration for recovery was initiated using an LTM candidate configuration. If a synchronous reconfiguration for recovery was not initiated using an LTM candidate configuration, the process proceeds to block 710. If a synchronous reconfiguration for recovery was initiated using an LTM candidate configuration, the process proceeds to block 703.

[0115] At block 703, the device determines whether the BWP is configured with RA resources for the 2-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 2-step RA type includes determining whether the BWP is configured with public RA resources for the 2-step RA type. If the BWP is configured with RA resources for the 2-step RA type, the process continues to block 704. If the BWP is not configured with RA resources for the 2-step RA type, the process continues to block 705.

[0116] At box 704, the device performs the action of setting the RA type to a 2-step RA type, similar to the action regarding... Figure 5A As described.

[0117] At block 705, the device determines whether the BWP is configured with RA resources for the 4-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 4-step RA type includes determining whether the BWP is configured with public RA resources for the 4-step RA type. If the BWP is not configured with RA resources for 4-step RA type random access, the process continues to block 709. If the BWP is configured with RA resources for the 4-step RA type, the process continues to block 706.

[0118] At block 706, the device determines whether the measured reference received power (RSRP) of the downlink path loss reference is higher than the message A threshold. If the measured RSRP of the downlink path loss reference is higher than the message A threshold, the procedure continues to block 707. If the measured RSRP of the downlink path loss reference is not higher than the message A threshold, the procedure continues to block 708.

[0119] At box 707, the device performs the action of setting the RA type to a 2-step RA type, similar to the action regarding... Figure 5A As described.

[0120] At box 708, the device performs the action of setting the RA type to a 4-step RA type, similar to the action regarding... Figure 5A As described.

[0121] At box 709, the device performs the action of setting the RA type to a 2-step RA type, similar to the action regarding... Figure 5AAs described.

[0122] At block 710, the device determines whether the BWP is configured with a dedicated, contention-free RA resource for the 4-step RA type. If the BWP is configured with a dedicated, contention-free RA resource for the 4-step RA type, the process proceeds to block 711. If the active BWP is not configured with a dedicated, contention-free RA resource for the 4-step RA type, the process proceeds to block 712.

[0123] At box 711, the device performs the action of setting the RA type to a 4-step RA type, similar to the action regarding... Figure 5A As described.

[0124] At block 712, the device determines whether the BWP is configured with a dedicated, contention-free RA resource for the 2-step RA type. If the BWP is configured with a dedicated, contention-free RA resource for the 2-step RA type, the process proceeds to block 713. If the BWP is not configured with a dedicated, contention-free RA resource for the 2-step RA type, the process proceeds to block 714.

[0125] At box 713, the device performs the action of setting the RA type to a 2-step RA type, similar to the action regarding... Figure 5A As described.

[0126] At box 714, the device performs the action of setting the RA type to a 4-step RA type, similar to the action regarding... Figure 5A As described.

[0127] At box 715, the device performs the RA process based on the set RA type, similar to the method described above. Figure 5A As described.

[0128] In some cases, it may be desirable for the base station to instruct the UE to perform synchronization via a fast RA procedure. For example, it may be desirable for the UE to quickly synchronize with another cell. In this case, the RA procedure can be initiated by a PDCCH command from the base station. In at least one example embodiment, the PDCCH command refers to a PDCCH transmission configured to cause the UE to perform the RA procedure specified by the PDCCH transmission. In at least one example embodiment, the PDCCH command indicates the RA resources to be used for the RA procedure. In at least one example embodiment, the PDCCH command is Downlink Control Information (DCI). In at least one example embodiment, the DCI is DCI Format 1_0. In at least one example embodiment, the DCI is scrambled with a Cell Radio Network Temporary Identifier (C-RNTI). In at least one example embodiment, the DCI includes a frequency domain resource allocation field. In at least one example embodiment, the scrambling of the DCI with the C-RNTI and the frequency domain allocation field setting each bit to a value of 1 indicate that the DCI is initiating an RA procedure according to the PDCCH command. For example, when a UE receives a DCI scrambled by C-RNTI, and the frequency domain allocation field has each bit set to a value of 1, the UE can determine that the DCI is initiating a RA procedure according to the PDCCH command.

[0129] In at least one example embodiment, the DCI includes a cell indicator field. In at least one example embodiment, the cell indicator field indicates the cell used to perform the RA procedure. In at least one example embodiment, the UE selects a set of RA resources configured corresponding to the cell indicated by the cell indicator field. In at least one example embodiment, the UE selects a set of RA resources configured in an early uplink synchronization configuration, which corresponds to the cell indicated by the cell indicator field. In at least one example embodiment, the early uplink synchronization configuration is an information element specifying the set of RA resources to be used for low-latency synchronization. Given that the PDCCH command is intended for fast UE synchronization, it may be desirable to utilize a 4-step RA type procedure to avoid potential delays due to reliability issues associated with 2-step RA type procedures. In at least one example embodiment, the UE performs a 4-step RA procedure in response to receiving a PDCCH command.

[0130] Figure 8 This is a flowchart illustrating activities associated with a random access procedure according to at least one example embodiment. In at least one example embodiment, there is a... Figure 8 The set of operations corresponding to the activities. Devices (e.g.) Figure 1 The electronic device 100, or a portion thereof, may utilize the set of operations. The device may include components for performing such operations, including, for example... Figure 1The processor 110. In an example embodiment, by enabling the memory (e.g. Figure 1 The memory 140 includes computer code to transform the device (e.g., Figure 1 Electronic device 100), the computer code is configured to work with a processor (e.g., Figure 1 The processor 110) works together to enable the device to perform Figure 8 The set of operations.

[0131] At box 801, the device initiates the RA process for the BWP by reconfiguring with synchronization.

[0132] At box 802, the device determines whether the RA process is initiated by a PDCCH command. If the RA process is initiated by a PDCCH command, the process continues to box 803. If the RA process is not initiated by a PDCCH command, the process continues to box 804.

[0133] At block 803, the device performs a 4-step RA using the RA resources indicated by the PDCCH command. In at least one example embodiment, the UE selects a set of RA resources configured in the early uplink synchronization configuration, which corresponds to the cell indicated by the cell indicator field, and performs a 4-step RA using the selected RA resources.

[0134] At block 804, the device determines whether the RA procedure is initiated by a synchronized reconfiguration. If the UE determines that the RA procedure is initiated by a synchronized reconfiguration, the process continues to block 805. If the UE determines that the RA procedure is not initiated by a synchronized reconfiguration, the process continues to block 818.

[0135] At block 805, the device determines whether a synchronous reconfiguration for recovery was initiated using an LTM candidate configuration. If a synchronous reconfiguration for recovery was not initiated using an LTM candidate configuration, the process proceeds to block 813. If a synchronous reconfiguration for recovery was initiated using an LTM candidate configuration, the process proceeds to block 806.

[0136] At block 806, the device determines whether the BWP is configured with RA resources for the 2-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 2-step RA type includes determining whether the BWP is configured with public RA resources for the 2-step RA type. If the BWP is configured with RA resources for the 2-step RA type, the process continues to block 807. If the BWP is not configured with RA resources for the 2-step RA type, the process continues to block 808.

[0137] At box 807, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0138] At block 808, the device determines whether the BWP is configured with RA resources for the 4-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 4-step RA type includes determining whether the BWP is configured with public RA resources for the 4-step RA type. If the BWP is not configured with RA resources for 4-step RA type random access, the process continues to block 812. If the BWP is configured with RA resources for the 4-step RA type, the process continues to block 809.

[0139] At block 809, the device determines whether the measured reference received power (RSRP) of the downlink path loss reference is higher than the message A threshold. If the measured RSRP of the downlink path loss reference is higher than the message A threshold, the procedure proceeds to block 810. If the measured RSRP of the downlink path loss reference is not higher than the message A threshold, the procedure proceeds to block 811.

[0140] At box 810, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0141] At box 811, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0142] At box 812, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0143] At box 813, the device determines whether the BWP is configured with a dedicated, contention-free RA resource for the 4-step RA type. If the BWP is configured with a dedicated, contention-free RA resource for the 4-step RA type, the process proceeds to box 814. If the active BWP is not configured with a dedicated, contention-free RA resource for the 4-step RA type, the process proceeds to box 815.

[0144] At box 814, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0145] At block 815, the device determines whether the BWP is configured with a dedicated, contention-free RA resource for the 2-step RA type. If the BWP is configured with a dedicated, contention-free RA resource for the 2-step RA type, the process proceeds to block 816. If the BWP is not configured with a dedicated, contention-free RA resource for the 2-step RA type, the process proceeds to block 817.

[0146] At box 816, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0147] At box 817, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0148] At box 818, the device performs RA based on an RA type determined by other standards. For example, the device may be based on a different type than the one specified in the standard. Figure 8 The standards discussed are used to determine the RA type.

[0149] As previously discussed, LTM uses low-layer signaling for reconfiguration while maintaining upper-layer configuration. To avoid higher-layer signaling, it may be desirable for the base station to invoke the LTM RA procedure via the LTM Cell Handover Media Access Control (MAC) control element (CE). In at least one example embodiment, the LTM Cell Handover MAC CE is the CE that commands the UE to perform an LTM cell handover. In at least one example embodiment, LTM cell handover involves the UE performing an RA procedure. Given that the LTM Cell Handover MAC CE is designed for fast UE synchronization, it may be desirable to utilize a 4-step RA type procedure to avoid potential delays due to reliability issues associated with 2-step RA type procedures. However, the LTM Cell Handover MAC CE may or may not indicate contention-free resources for the associated RA procedure. In at least one example embodiment, when the LTM Cell Handover MAC CE indicates contention-free random access resources, the UE uses the contention-free resources indicated by the LTM Cell Handover MAC CE to perform the 4-step RA. However, when the LTM Cell Handover MAC CE does not indicate contention-free random access resources, the UE determines the RA type based on RA resource configuration information external to the LTM Cell Handover MAC CE.

[0150] Figure 9 This is a flowchart illustrating activities associated with a random access procedure according to at least one example embodiment. In at least one example embodiment, there is a... Figure 9 The set of operations corresponding to the activities. Devices (e.g.) Figure 1The electronic device 100, or a portion thereof, may utilize the set of operations. The device may include components for performing such operations, including, for example... Figure 1 The processor 110. In an example embodiment, by enabling the memory (e.g. Figure 1 The memory 140 includes computer code to transform the device (e.g., Figure 1 Electronic device 100), the computer code is configured to work with a processor (e.g., Figure 1 The processor 110) works together to enable the device to perform Figure 9 The set of operations.

[0151] At frame 901, the device initiates the RA process for the BWP.

[0152] At box 902, the device determines whether the RA procedure is initiated by a synchronized reconfiguration. If the UE determines that the RA procedure is initiated by a synchronized reconfiguration, the process continues to box 903. If the UE determines that the RA procedure is not initiated by a synchronized reconfiguration, the process continues to box 916.

[0153] At block 903, the device determines whether a synchronous reconfiguration for recovery was initiated using an LTM candidate configuration. If a synchronous reconfiguration for recovery was not initiated using an LTM candidate configuration, the process proceeds to block 915. If a synchronous reconfiguration for recovery was initiated using an LTM candidate configuration, the process proceeds to block 904.

[0154] At block 904, the device determines whether the BWP is configured with RA resources for the 2-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 2-step RA type includes determining whether the BWP is configured with public RA resources for the 2-step RA type. If the BWP is configured with RA resources for the 2-step RA type, the process continues to block 905. If the BWP is not configured with RA resources for the 2-step RA type, the process continues to block 906.

[0155] At box 905, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0156] At block 906, the device determines whether the BWP is configured with RA resources for the 4-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 4-step RA type includes determining whether the BWP is configured with public RA resources for the 4-step RA type. If the BWP is not configured with RA resources for 4-step RA type random access, the process continues to block 910. If the BWP is configured with RA resources for the 4-step RA type, the process continues to block 907.

[0157] At block 907, the device determines whether the measured reference received power (RSRP) of the downlink path loss reference is higher than the message A threshold. If the measured RSRP of the downlink path loss reference is higher than the message A threshold, the procedure continues to block 908. If the measured RSRP of the downlink path loss reference is not higher than the message A threshold, the procedure continues to block 909.

[0158] At box 908, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0159] At box 909, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0160] At box 910, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0161] At block 911, the device determines whether the BWP is configured with a dedicated, contention-free RA resource for the 4-step RA type. If the BWP is configured with a dedicated, contention-free RA resource for the 4-step RA type, the process continues to block 912. If the active BWP is not configured with a dedicated, contention-free RA resource for the 4-step RA type, the process continues to block 913.

[0162] At box 912, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0163] At block 913, the device determines whether the BWP is configured with a dedicated, contention-free RA resource for the 2-step RA type. If the BWP is configured with a dedicated, contention-free RA resource for the 2-step RA type, the process proceeds to block 914. If the BWP is not configured with a dedicated, contention-free RA resource for the 2-step RA type, the process proceeds to block 915.

[0164] At box 914, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0165] At box 915, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0166] At box 916, the device determines whether the RA procedure is initiated by the LTM cell handover media access control (MAC) element (CE). If the device determines that the RA procedure is initiated by the LTM cell handover media access control (MAC) element (CE), the procedure continues to box 917. If the device determines that the RA procedure is not initiated by the LTM cell handover media access control (MAC) element (CE), the procedure continues to box 926.

[0167] At box 917, the device determines whether the LTM cell handover MAC CE indicates contention-free random access resources. If the LTM cell handover MAC CE indicates contention-free random access resources, the procedure continues to box 918. If the LTM cell handover MAC CE does not indicate contention-free random access resources, the procedure continues to box 919.

[0168] At box 918, the device performs a 4-step RA using contention-free resources indicated by the LTM cell handover MAC CE.

[0169] At block 919, the device determines whether the BWP is configured with RA resources for the 2-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 2-step RA type includes determining whether the BWP is configured with public RA resources for the 2-step RA type. If the BWP is configured with RA resources for the 2-step RA type, the process continues to block 920. If the BWP is not configured with RA resources for the 2-step RA type, the process continues to block 921.

[0170] At box 920, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0171] At block 921, the device determines whether the BWP is configured with RA resources for the 4-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 4-step RA type includes determining whether the BWP is configured with public RA resources for the 4-step RA type. If the BWP is not configured with RA resources for 4-step RA type random access, the process continues to block 925. If the BWP is configured with RA resources for the 4-step RA type, the process continues to block 922.

[0172] At block 922, the device determines whether the measured reference received power (RSRP) of the downlink path loss reference is higher than the message A threshold. If the measured RSRP of the downlink path loss reference is higher than the message A threshold, the procedure proceeds to block 923. If the measured RSRP of the downlink path loss reference is not higher than the message A threshold, the procedure proceeds to block 924.

[0173] At box 923, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0174] At box 924, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0175] At box 925, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0176] At box 926, the device performs the RA based on the RA type determined by other standards. For example, the device may be based on a different type than the one specified in the standard. Figure 9 The standards discussed are used to determine the RA type.

[0177] Figure 10 This is a flowchart illustrating activities associated with a random access procedure according to at least one example embodiment. In at least one example embodiment, there is a... Figure 10 The set of operations corresponding to the activities. Devices (e.g.) Figure 1 The electronic device 100, or a portion thereof, may utilize the set of operations. The device may include components for performing such operations, including, for example... Figure 1 The processor 110. In an example embodiment, by enabling the memory (e.g. Figure 1 The memory 140 includes computer code to transform the device (e.g., Figure 1 Electronic device 100), the computer code is configured to work with a processor (e.g., Figure 1The processor 110) works together to enable the device to perform Figure 10 The set of operations.

[0178] At box 1001, the device initiates the RA process for the BWP by reconfiguring with synchronization.

[0179] At box 1002, the device determines whether the RA process is initiated by a PDCCH command. If the RA process is initiated by a PDCCH command, the process continues to box 1003. If the RA process is not initiated by a PDCCH command, the process continues to box 1004.

[0180] At box 1003, the device performs a 4-step RA using the RA resources indicated by the PDCCH command. In at least one example embodiment, the UE selects a set of RA resources configured in the early uplink synchronization configuration, which corresponds to the cell indicated by the cell indicator field, and performs a 4-step RA using the selected RA resources.

[0181] At box 1004, the device determines whether the RA procedure is initiated by a synchronized reconfiguration. If the UE determines that the RA procedure is initiated by a synchronized reconfiguration, the process continues to box 1005. If the UE determines that the RA procedure is not initiated by a synchronized reconfiguration, the process continues to box 1019.

[0182] At box 1005, the device determines whether a synchronous reconfiguration for recovery was initiated using an LTM candidate configuration. If a synchronous reconfiguration for recovery was not initiated using an LTM candidate configuration, the process proceeds to box 1014. If a synchronous reconfiguration for recovery was initiated using an LTM candidate configuration, the process proceeds to box 1006.

[0183] At block 1006, the device determines whether the BWP is configured with RA resources for the 2-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 2-step RA type includes determining whether the BWP is configured with public RA resources for the 2-step RA type. If the BWP is configured with RA resources for the 2-step RA type, the process continues to block 1008. If the BWP is not configured with RA resources for the 2-step RA type, the process continues to block 1009.

[0184] At box 1008, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0185] At block 1009, the device determines whether the BWP is configured with RA resources for the 4-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 4-step RA type includes determining whether the BWP is configured with public RA resources for the 4-step RA type. If the BWP is not configured with RA resources for 4-step RA type random access, the process continues to block 1013. If the BWP is configured with RA resources for the 4-step RA type, the process continues to block 1010.

[0186] At block 1010, the device determines whether the measured reference received power (RSRP) of the downlink path loss reference is higher than the message A threshold. If the measured RSRP of the downlink path loss reference is higher than the message A threshold, the procedure proceeds to block 1011. If the measured RSRP of the downlink path loss reference is not higher than the message A threshold, the procedure proceeds to block 1012.

[0187] At box 1011, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0188] At box 1012, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0189] At box 1013, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0190] At box 1014, the device determines whether the BWP is configured with a dedicated, contention-free RA resource for the 4-step RA type. If the BWP is configured with a dedicated, contention-free RA resource for the 4-step RA type, the process proceeds to box 1015. If the active BWP is not configured with a dedicated, contention-free RA resource for the 4-step RA type, the process proceeds to box 1016.

[0191] At box 1015, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0192] At block 1016, the device determines whether the BWP is configured with a dedicated, contention-free RA resource for the 2-step RA type. If the BWP is configured with a dedicated, contention-free RA resource for the 2-step RA type, the process proceeds to block 1017. If the BWP is not configured with a dedicated, contention-free RA resource for the 2-step RA type, the process proceeds to block 1018.

[0193] At box 1017, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0194] At box 1018, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0195] At box 1019, the device determines whether the RA procedure is initiated by the LTM cell handover media access control (MAC) element (CE). If the device determines that the RA procedure is initiated by the LTM cell handover media access control (MAC) element (CE), the process continues to box 1020. If the device determines that the RA procedure is not initiated by the LTM cell handover media access control (MAC) element (CE), the process continues to box 1029.

[0196] At box 1020, the device determines whether the LTM cell handover MAC CE indicates contention-free random access resources. If the LTM cell handover MAC CE indicates contention-free random access resources, the procedure continues to box 1021. If the LTM cell handover MAC CE does not indicate contention-free random access resources, the procedure continues to box 1022.

[0197] At box 1021, the device performs a 4-step RA using contention-free resources indicated by the LTM cell handover MAC CE.

[0198] At block 1022, the device determines whether the BWP is configured with RA resources for the 2-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 2-step RA type includes determining whether the BWP is configured with public RA resources for the 2-step RA type. If the BWP is configured with RA resources for the 2-step RA type, the process continues to block 1023. If the BWP is not configured with RA resources for the 2-step RA type, the process continues to block 1024.

[0199] At box 1023, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0200] At block 1024, the device determines whether the BWP is configured with RA resources for the 4-step RA type. In at least one example embodiment, determining whether the BWP is configured with RA resources for the 4-step RA type includes determining whether the BWP is configured with public RA resources for the 4-step RA type. If the BWP is not configured with RA resources for 4-step RA type random access, the process continues to block 1028. If the BWP is configured with RA resources for the 4-step RA type, the process continues to block 1025.

[0201] At box 1025, the device determines whether the measured reference received power (RSRP) of the downlink path loss reference is higher than the message A threshold. If the measured RSRP of the downlink path loss reference is higher than the message A threshold, the procedure continues to box 1026. If the measured RSRP of the downlink path loss reference is not higher than the message A threshold, the procedure continues to box 1027.

[0202] At box 1026, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0203] At box 1027, the device performs a 4-step RA type. The performance of the 4-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0204] At box 1028, the device performs a 2-step RA type. The performance of the 2-step RA type can be similar to that of the device described above. Figures 5A-5B The performance described.

[0205] At box 1029, the device performs the RA based on the RA type determined by other standards. For example, the device may be based on a different RA type than that specified in the standard. Figure 10 The standard discussed is used to determine the RA type.

[0206] Embodiments of the present invention can be implemented in software, hardware, application logic, or a combination of software, hardware, and application logic. The software, application logic, and / or hardware can reside on a device, a separate device, or multiple separate devices. Depending on the need, a portion of the software, application logic, and / or hardware can reside on a device, a portion of the software, application logic, and / or hardware can reside on a separate device, or a portion of the software, application logic, and / or hardware can reside on multiple separate devices. In exemplary embodiments, the application logic, software, or instruction set is maintained on any of a variety of conventional computer-readable media.

[0207] Although various aspects of the invention are set forth in the independent claims, other aspects of the invention include other combinations of features from the described embodiments and / or dependent claims having features of the independent claims, and not only the combinations expressly stated in the claims.

[0208] It should also be noted in this document that although exemplary embodiments of the invention have been described above, these descriptions should not be considered limiting. Rather, various changes and modifications can be made without departing from the scope of the invention as defined by the appended claims.

Claims

1. A method executed by a UE, the method comprising: Initiate a random access (RA) procedure for the bandwidth portion (BWP) by reconfiguring with synchronization; Determine whether to initiate the synchronized reconfiguration for recovery using the Low-Level Triggered Mobility (LTM) candidate configuration; Without initiating the synchronized reconfiguration for recovery using the LTM candidate configuration: Determine whether the BWP is configured with a dedicated, non-contested RA resource for the 4-step RA type; When the BWP is configured with the dedicated, non-contending RA resource for the 4-step RA type, perform the 4-step RA. In the case where the BWP is not configured with the dedicated, non-contested RA resource for the 4-step RA type: Determine whether the BWP is configured with a dedicated, non-contested RA resource for the 2-step RA type; When the BWP is configured with the dedicated, non-contact RA resource for the 2-step RA type, the 2-step RA is performed. If the BWP is not configured with the dedicated, non-contested RA resource for the 2-step RA type, perform a 4-step RA. as well as In the case of initiating the synchronous reconfiguration for recovery using the LTM candidate configuration: It was determined that the BWP was not configured with RA resources for the 2-step RA type; Determine whether the BWP is configured with RA resources for the 4-step RA type; If the BWP is not configured with RA resources for 4-step RA type random access, perform 2-step RA; In the case where the BWP is configured with RA resources for a 4-step RA type: Determine whether the measured reference received power (RSRP) for downlink path loss reference is higher than the threshold of message A; If the measured RSRP of the downlink path loss reference is higher than the threshold of message A, perform a 2-step RA. as well as If the measured RSRP of the downlink path loss reference is not higher than the threshold of message A, perform a 4-step RA.

2. The method of claim 1, wherein the dedicated, contention-free RA resource is received in the rach-configDedicated information element.

3. The method of claim 1, wherein determining whether the BWP is configured with RA resources for the 2-step RA type includes determining whether the BWP is configured with public RA resources for the 2-step RA type.

4. The method of claim 1, wherein determining whether the BWP is configured with RA resources for the 4-step RA type includes determining whether the BWP is configured with public RA resources for the 4-step RA type.

5. The method of claim 1, wherein initiating the synchronized reconfiguration for recovery using the LTM candidate configuration includes: The previous synchronous reconfiguration failed, and the UE is configured with a stored conditional RRC reconfiguration associated with the LTM candidate configuration.

6. The method of claim 1, wherein performing a 2-step RA includes setting the RA type to be performed as a 2-step RA type and performing the RA process based on the set RA type to be performed, and wherein performing a 4-step RA includes setting the RA type to be performed as a 4-step RA type and performing the RA process based on the set RA type to be performed.

7. The method of claim 1, wherein performing the 2-step RA includes selecting an RA resource set and performing the RA process based on the RA type specified by the selected RA resource set, and wherein performing the 4-step RA includes selecting a different RA resource set and performing the RA process based on the RA type specified by the different selected RA resource set.

8. A UE, comprising: At least one processor, and At least one memory, the memory including machine-readable instructions, which, when executed by the processor, cause the UE to perform: Initiate a random access (RA) procedure for the bandwidth portion (BWP) by reconfiguring with synchronization; Determine whether the synchronized reconfiguration for recovery was initiated using a low-level triggered mobility (LTM) candidate configuration; Without initiating the synchronized reconfiguration for recovery using the LTM candidate configuration: Determine whether the BWP is configured with a dedicated, non-contested RA resource for the 4-step RA type; When the BWP is configured with the dedicated, non-contending RA resource for the 4-step RA type, perform the 4-step RA. In the case where the BWP is not configured with the dedicated, non-contested RA resource for the 4-step RA type: Determine whether the BWP is configured with a dedicated, non-contested RA resource for the 2-step RA type; When the BWP is configured with the dedicated, non-contact RA resource for the 2-step RA type, the 2-step RA is performed. If the BWP is not configured with the dedicated, non-contested RA resource for the 2-step RA type, perform a 4-step RA. as well as In the case of initiating the synchronous reconfiguration for recovery using the LTM candidate configuration: It was determined that the BWP was not configured with RA resources for the 2-step RA type; Determine whether the BWP is configured with RA resources for the 4-step RA type; If the BWP is not configured with RA resources for 4-step RA type random access, perform 2-step RA; In the case where the BWP is configured with RA resources for a 4-step RA type: Determine whether the measured reference received power (RSRP) for downlink path loss reference is higher than the threshold of message A; If the measured RSRP of the downlink path loss reference is higher than the threshold of message A, perform a 2-step RA. as well as If the measured RSRP of the downlink path loss reference is not higher than the threshold of message A, perform a 4-step RA.

9. The UE of claim 8, wherein the dedicated, contention-free RA resource is received in the rach-configDedicated information element.

10. The UE of claim 8, wherein determining whether the BWP is configured with RA resources for the 2-step RA type includes determining whether the BWP is configured with public RA resources for the 2-step RA type.

11. The UE of claim 8, wherein determining whether the BWP is configured with RA resources for the 4-step RA type includes determining whether the BWP is configured with public RA resources for the 4-step RA type.

12. The UE of claim 8, wherein initiating the synchronized reconfiguration for recovery using an LTM candidate configuration includes: The previous synchronous reconfiguration failed, and the UE is configured with a stored conditional RRC reconfiguration associated with the LTM candidate configuration.

13. The UE of claim 8, wherein performing a 2-step RA includes setting the RA type to be performed as a 2-step RA type and performing the RA process based on the set RA type to be performed, and wherein performing a 4-step RA includes setting the RA type to be performed as a 4-step RA type and performing the RA process based on the set RA type to be performed.

14. The UE of claim 8, wherein performing a 2-step RA includes selecting an RA resource set and performing the RA procedure based on the RA type specified by the selected RA resource set, and wherein performing a 4-step RA includes selecting a different RA resource set and performing the RA procedure based on the RA type specified by the different selected RA resource set.

15. At least one non-transitory computer-readable medium, the non-transitory computer-readable medium comprising instructions that, when executed by a UE, perform: Initiate a random access (RA) procedure for the bandwidth portion (BWP) by reconfiguring with synchronization; Determine whether the synchronized reconfiguration for recovery was initiated using a low-level triggered mobility (LTM) candidate configuration; Without initiating the synchronized reconfiguration for recovery using the LTM candidate configuration: Determine whether the BWP is configured with a dedicated, non-contested RA resource for the 4-step RA type; When the BWP is configured with the dedicated, non-contending RA resource for the 4-step RA type, perform the 4-step RA. In the case where the BWP is not configured with the dedicated, non-contested RA resource for the 4-step RA type: Determine whether the BWP is configured with a dedicated, non-contested RA resource for the 2-step RA type; When the BWP is configured with the dedicated, non-contact RA resource for the 2-step RA type, the 2-step RA is performed. If the BWP is not configured with the dedicated, non-contested RA resource for the 2-step RA type, perform a 4-step RA. as well as In the case of initiating the synchronous reconfiguration for recovery using the LTM candidate configuration: It was determined that the BWP was not configured with RA resources for the 2-step RA type; Determine whether the BWP is configured with RA resources for the 4-step RA type; If the BWP is not configured with RA resources for 4-step RA type random access, perform 2-step RA; In the case where the BWP is configured with RA resources for a 4-step RA type: Determine whether the measured reference received power (RSRP) for downlink path loss reference is higher than the threshold of message A; If the measured RSRP of the downlink path loss reference is higher than the threshold of message A, perform a 2-step RA. as well as If the measured RSRP of the downlink path loss reference is not higher than the threshold of message A, perform a 4-step RA.

16. The medium of claim 15, wherein the dedicated, contention-free RA resource is received in the rach-configDedicated information element.

17. The medium of claim 15, wherein determining whether the BWP is configured with RA resources for the 2-step RA type includes determining whether the BWP is configured with public RA resources for the 2-step RA type.

18. The medium of claim 15, wherein determining whether the BWP is configured with RA resources for the 4-step RA type includes determining whether the BWP is configured with public RA resources for the 4-step RA type.

19. The medium of claim 15, wherein initiating the synchronized reconfiguration for recovery using an LTM candidate configuration includes: The previous synchronous reconfiguration failed, and the UE is configured with a stored conditional RRC reconfiguration associated with the LTM candidate configuration.

20. The medium of claim 15, wherein performing a two-step RA includes selecting an RA resource set and performing the RA process based on the RA type specified by the selected RA resource set, and wherein performing a four-step RA includes selecting a different RA resource set and performing the RA process based on the RA type specified by the different selected RA resource set.

Images