Two-step random access procedure in wireless communication

Abstract

Aspects of the present disclosure relate to random access channel (RACH) procedures that allow a user equipment (UE) to achieve synchronization with a network and obtain network resources and services. The present disclosure provides various options for implementing a two-step RACH procedure, which can support various UE behaviors related to monitoring of a physical downlink control channel (PDCCH) during the two-step RACH procedure.

Description

Technical Field

[0001] The techniques discussed below generally relate to wireless communication systems, and more specifically to random access procedures within wireless communication systems. Background Technology

[0002] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, message sending and receiving, and broadcasting. These systems can be accessed by various types of devices suitable for facilitating wireless communication, with multiple devices sharing available system resources (e.g., time, frequency, and power). In a communication network, a user equipment (UE) can use a procedure called random access (RA) to obtain uplink synchronization and a designated network identifier for radio access communication with the network.

[0003] With the increasing demand for mobile broadband access, research and development are constantly advancing wireless communication technologies, not only to meet the growing demand for mobile broadband access, but also to improve and enhance the user experience of mobile communications. For example, the 3rd Generation Partnership Project (3GPP) is an organization that develops telecommunications standards for new 5G radio networks. Summary of the Invention

[0004] The following provides an overview of one or more aspects of this disclosure in order to provide a basic understanding of such aspects. This overview is not an exhaustive summary of all intended features of this disclosure, nor is it intended to identify key or essential elements of all aspects of this disclosure or to describe the scope of any or all aspects of this disclosure. Its sole purpose is to present some concepts of one or more aspects of this disclosure in one form as a prelude to the more detailed description that follows.

[0005] This disclosure relates to a random access channel (RACH) procedure that allows a user equipment (UE) to synchronize with the network and obtain network resources and services. This disclosure provides various options for implementing a two-step RACH procedure that can support various UE behaviors related to monitoring of the physical downlink control channel (PDCCH) during the two-step RACH procedure.

[0006] One aspect of this disclosure provides a method for wireless communication for a random access procedure at a scheduling entity. The scheduled entity sends a first message to the scheduling entity during the random access procedure. The first message includes a Physical Random Access Channel (PRACH) preamble sequence for the random access procedure. If the first message includes information for determining the device-specific network identifier (e.g., C-RNTI) of the scheduled entity, the scheduled entity monitors the Physical Downlink Control Channel (PDCCH) of a second message sent by the scheduling entity in response to the first message, and the second message is scrambled with the device-specific network identifier of the scheduled entity.

[0007] Another aspect of this disclosure provides a method for wireless communication for a random access procedure at a scheduled entity. The scheduled entity sends a first message to a scheduling entity during the random access procedure. The first message includes a PRACH preamble sequence for the random access procedure. Regardless of whether the first message includes information for determining the device-specific network identifier of the scheduled entity, the scheduled entity monitors the PDCCH of a second message sent by the scheduling entity in response to the first message, and the second message is scrambled by the device-specific network identifier of the scheduled entity.

[0008] Another aspect of this disclosure provides a method for wireless communication for random access procedures at a scheduled entity. The scheduled entity receives configuration information from a scheduling entity for configuring the scheduled entity in relation to the random access procedure. The scheduled entity sends a first message to the scheduling entity, the first message including at least a PRACH preamble sequence for the random access procedure. The scheduled entity monitors a PDCCH in response to the first message based on the configuration information. The second message may be scrambled by a device-specific network identifier of the scheduled entity.

[0009] The configuration information can configure the scheduled entity to monitor the PDCCH of the second message based on at least one of the following: the type of random access procedure, the scheduled event of the random access procedure, the spectrum used to transmit the first transmission, or the radio conditions between the scheduled entity and the scheduling entity.

[0010] Another aspect of this disclosure provides a user equipment (UE) for wireless communication. The UE includes a communication interface configured for wireless communication with a scheduling entity, a memory, and a processor operatively coupled to the communication interface and the memory. The processor and memory are configured to send a first message to the scheduling entity including a PRACH preamble sequence for a random access procedure. The processor and memory are also configured to: if the first message includes information for determining a device-specific network identifier (PSI) of the UE, monitor the PDCCH of a second message sent by the scheduling entity in response to the first message, and scramble the second message with the PDI of the UE.

[0011] Another aspect of this disclosure provides a user equipment (UE) for wireless communication. The UE includes a communication interface configured for wireless communication with a scheduling entity, a memory, and a processor operatively coupled to the communication interface and the memory. The processor and memory are configured to send a first message to the scheduling entity including a PRACH preamble sequence for a random access procedure. The processor and memory are also configured to monitor the PDCCH of a second message sent by the scheduling entity in response to the first message, regardless of whether the first message includes information for determining the UE's device-specific network identifier, the second message being scrambled with the UE's device-specific network identifier.

[0012] Another aspect of this disclosure provides a user equipment (UE) for wireless communication. The UE includes a communication interface configured for wireless communication with a scheduling entity, a memory, and a processor operatively coupled to the communication interface and the memory. The processor and memory are also configured to receive configuration information from the scheduling entity for configuring the UE in relation to a random access procedure. The processor and memory are further configured to send a first message to the scheduling entity, the first message including at least a PRACH preamble sequence for the random access procedure. The processor and memory are also configured to monitor a PDCCH in response to a second message based on the configuration information.

[0013] These and other aspects of the invention will become more fully understood upon reading the following detailed description. Other aspects, features, and embodiments will be apparent to those skilled in the art after reading the following description of specific exemplary embodiments in conjunction with the accompanying drawings. Although features are discussed below with respect to certain embodiments and drawings, all embodiments may include one or more of the advantageous features discussed herein. In other words, while one or more embodiments may be discussed having certain advantageous features, one or more of such features may also be used according to the various embodiments discussed herein. Similarly, although exemplary embodiments may be discussed below as embodiments of an apparatus, system, or method, it should be understood that such exemplary embodiments may be implemented in various apparatuses, systems, and methods. Attached Figure Description

[0014] Figure 1 This is a schematic illustration of a wireless communication system based on some aspects of this disclosure.

[0015] Figure 2 This is a conceptual description of radio access networks based on some aspects of this disclosure.

[0016] Figure 3 This is a flowchart illustrating an example of a two-step random access procedure according to some aspects of this disclosure.

[0017] Figure 4 This is a block diagram that conceptually illustrates an example of a hardware implementation of a scheduling entity according to some aspects of this disclosure.

[0018] Figure 5 This is a block diagram that conceptually illustrates an example of a hardware implementation of a scheduled entity according to some aspects of this disclosure.

[0019] Figure 6 This is a flowchart illustrating a first exemplary process for a two-step random access procedure according to some aspects of this disclosure.

[0020] Figure 7 This is a flowchart illustrating a second exemplary process for a two-step random access procedure according to some aspects of this disclosure.

[0021] Figure 8 This is a flowchart illustrating a third exemplary process for a two-step random access procedure according to some aspects of this disclosure. Detailed Implementation

[0022] The detailed description that follows, taken in conjunction with the accompanying drawings, is intended as a description of various configurations and not as representing the only configuration in which the concepts described herein can be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts can be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form to avoid obscuring such concepts.

[0023] While aspects and embodiments of this application are described through the illustration of a few examples, those skilled in the art will understand that additional implementations and use cases may arise in many different arrangements and scenarios. The innovations described herein can be implemented across many different platform types, devices, systems, shapes, sizes, and package arrangements. For example, embodiments and / or use cases may arise via integrated chip embodiments and other devices based on non-modular components (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchase devices, medical devices, AI-enabled devices, etc.). While some examples may or may not be specific to particular use cases or applications, broad applicability of the described innovations can emerge. The range of implementations can extend from chip-level or modular components to non-modular, non-chip-level implementations, and further to aggregated, distributed, or OEM devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating the described aspects and features may also necessary include additional components and features for implementing and practicing the claimed and described embodiments. For example, the transmission and reception of wireless signals require multiple components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors (multiple), interleavers, adders / summers, etc.). The innovations described herein are intended to be implemented in a wide variety of devices, chip-level components, systems, distributed deployments, end-user devices, etc., of various sizes, shapes, and configurations.

[0024] This disclosure relates to a random access channel (RACH) procedure that allows a user equipment (UE) to synchronize with the network and obtain network resources and services. This disclosure provides various options for implementing a two-step RACH procedure that can support various UE behaviors related to monitoring of the physical downlink control channel (PDCCH) during the two-step RACH procedure.

[0025] The various concepts presented herein can be implemented across a wide variety of telecommunications systems, network architectures, and communication standards. References are now available. Figure 1 By way of illustrative example and not limitation, reference is made to a wireless communication system 100 to illustrate various aspects of this disclosure. The wireless communication system 100 includes three interaction domains: a core network 102, a radio access network (RAN) 104, and a user equipment (UE) 106. Through the wireless communication system 100, the UE 106 can be enabled to perform data communication with an external data network 110 (such as, but not limited to, the Internet).

[0026] RAN 104 can implement any suitable wireless communication technology or multiple technologies to provide radio access to UE 106. As an example, RAN 104 can operate according to the 3rd Generation Partnership Project (3GPP) New Radio (NR) specification (commonly referred to as 5G). As another example, RAN 104 can operate under a hybrid of 5G NR and the Evolved Universal Terrestrial Radio Access Network (eUTRAN) standard (commonly referred to as LTE). 3GPP refers to this hybrid RAN as Next Generation RAN, or NG-RAN. Of course, many other examples can be utilized within the scope of this disclosure.

[0027] As shown, RAN 104 includes multiple base stations 108. Broadly speaking, a base station is a network element in a radio access network responsible for radio transmission and reception to or from a UE in one or more cells. In different technologies, standards, or contexts, a base station may also be referred to by those skilled in the art as a base transceiver station (BTS), radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), access point (AP), node B (NB), eNode B (eNB), gNode B (gNB), or some other suitable term.

[0028] Radio access network 104 is further shown to support wireless communication for multiple mobile devices. A mobile device may be referred to as a User Equipment (UE) in the 3GPP standard, but may also be referred to by those skilled in the art as a Mobile Station (MS), Subscriber Station, Mobile Unit, Subscriber Unit, Radio Unit, Remote Unit, Mobile Device, Radio Device, Wireless Communication Device, Remote Device, Mobile Subscriber Station, Access Terminal (AT), Mobile Terminal, Radio Terminal, Remote Terminal, Handheld Device, Terminal, User Agent, Mobile Client, Client, or any other suitable term. A UE may be an apparatus (e.g., a mobile device) that provides access to network services to a user.

[0029] Within this document, a “mobile” device does not necessarily need to be mobile and can be stationary. The term mobile device or mobile equipment refers to a wide variety of devices and technologies. A UE can include multiple hardware structural components of a size and shape designed and arranged to facilitate communication; such components can include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc., electrically coupled to each other. For example, some non-limiting examples of mobile devices include mobile devices, cellular phones, smartphones, Session Initiation Protocol (SIP) phones, laptops, personal computers (PCs), laptops, netbooks, smartbooks, tablets, personal digital assistants (PDAs), and a wide variety of embedded systems, such as those corresponding to the “Internet of Things” (IoT). A mobile device can also be an autonomous or other transport vehicle, a remote sensor or actuator, a robot or robotic device, a satellite radio, a Global Positioning System (GPS) device, an object tracking device, a drone, a multi-rotor aircraft, a quadcopter, a remotely controlled device, consumer and / or wearable devices (such as glasses, wearable cameras, virtual reality devices, smartwatches, health or fitness trackers), digital audio players (e.g., MP3 players), cameras, game consoles, etc. Mobile devices can also be digital home or smart home devices (such as home audio, video and / or multimedia devices), appliances, vending machines, smart lighting, home security systems, smart meters, and so on. Mobile devices can also be smart energy devices, security devices, solar panels or solar arrays, urban infrastructure devices controlling electrical power (e.g., smart grids), lighting, water, etc.; industrial automation and enterprise equipment; logistics controllers; agricultural equipment; military defense equipment, vehicles, aircraft, ships, and weapons, etc. Furthermore, mobile devices can provide networked or telemedicine support, such as remote healthcare. Remote healthcare devices can include remote healthcare monitoring devices and remote healthcare supervision devices, whose communications can be prioritized, for example, through priority access to critical service data transmission and / or related QoS for critical service data transmission, or prioritized over other types of information.

[0030] Wireless communication between RAN 104 and UE 106 can be described as utilizing an air interface. Transmissions over the air interface from a base station (e.g., base station 108) to one or more UEs (e.g., UE 106) can be referred to as downlink (DL) transmissions. According to certain aspects of this disclosure, the term downlink can refer to point-to-multipoint transmissions originating at a scheduling entity (further described below; e.g., base station 108). Another way to describe this scheme is to use the term broadcast channel multiplexing. Transmissions from a UE (e.g., UE 106) to a base station (e.g., base station 108) can be referred to as uplink (UL) transmissions. According to a further aspect of this disclosure, the term uplink can refer to point-to-point transmissions originating at a scheduled entity (further described below; e.g., UE 106).

[0031] In some examples, access to the air interface can be scheduled, where a scheduling entity (e.g., base station 108) allocates resources for communication between some or all devices and equipment within its service area or cell. Within this disclosure, as further discussed below, the scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more scheduled entities. That is, for scheduled communication, UE 106 (which may be a scheduled entity) can utilize the resources allocated by scheduling entity 108.

[0032] Base station 108 is not the only entity that can be used as a scheduling entity. That is, in some examples, a UE can be used as a scheduling entity to schedule resources for one or more scheduled entities (e.g., one or more other UEs).

[0033] like Figure 1 As shown, scheduling entity 108 can broadcast downlink service 112 to one or more scheduled entities 106. Broadly speaking, scheduling entity 108 is a node or device responsible for scheduling services (including downlink service 112 and, in some examples, uplink service 116 from one or more scheduled entities 106 to scheduling entity 108) in a wireless communication network. On the other hand, scheduled entity 106 is a node or device that receives downlink control information 114 (including but not limited to scheduling information (e.g., authorization), synchronization or timing information), or other control information from another entity in the wireless communication network (such as scheduling entity 108).

[0034] Generally, base station 108 may include a backhaul interface for communicating with the backhaul section 120 of a wireless communication system. Backhaul 120 provides a link between base station 108 and core network 102. Furthermore, in some examples, the backhaul network may provide interconnection between the respective base stations 108. Various types of backhaul interfaces can be employed, such as a direct physical connection using any suitable transport network, a virtual network, etc.

[0035] The core network 102 may be part of the wireless communication system 100 and may be independent of the radio access technology used in the RAN 104. In some examples, the core network 102 may be configured according to a 5G standard (e.g., 5GC). In other examples, the core network 102 may be configured according to a 4G evolved packet core (EPC) or any other suitable standard or configuration.

[0036] Now for reference Figure 2 The RAN 200 is provided as an illustrative example rather than a limitation. In some examples, the RAN 200 may be described above and... Figure 1 The same as RAN 104 shown. The geographical area covered by RAN 200 can be divided into cellular areas (cells), which can be uniquely identified by user equipment (UE) based on an identifier broadcast from an access point or base station. Figure 2 Macro cells 202, 204, and 206, and small cell 208 are shown, each of which may include one or more sectors (not shown). A sector is a sub-area of ​​a cell. All sectors within a cell are served by the same base station. Radio links within a sector can be identified by a single logical identifier belonging to that sector. In a cell divided into sectors, multiple sectors within the cell can be formed by separate antenna groups, where each antenna is responsible for communication with UEs in a portion of the cell.

[0037] exist Figure 2 In the illustration, two base stations 210 and 212 are shown in cells 202 and 204; and a third base station 214 is shown as a remote radio head (RRH) 216 in control cell 206. That is, the base stations can have integrated antennas, or they can be connected to the antenna or RRH via feed cables. In the illustrated example, cells 202, 204, and 216 can be referred to as macro cells because base stations 210, 212, and 214 support cells with large sizes. Furthermore, base station 218 is shown in small cell 208 (e.g., microcell, picocell, femtocell, home base station, home Node B, home eNode B, etc.), which may overlap with one or more macro cells. In this example, cell 208 can be referred to as a small cell because base station 218 supports cells with relatively small sizes. Cell size design can be accomplished based on system design and component constraints.

[0038] It will be understood that the radio access network 200 may include any number of wireless base stations and cells. Furthermore, relay nodes may be deployed to extend the size or coverage area of ​​a given cell. Base stations 210, 212, 214, and 218 provide wireless access points to the core network for any number of mobile devices. In some examples, base stations 210, 212, 214, and / or 218 may be used in conjunction with those described above and in… Figure 1 The base station / scheduling entity 108 shown is the same.

[0039] Figure 2 It also includes a quadcopter or drone 220, which can be configured to be used as a base station. That is, in some examples, the cell does not have to be fixed, and the geographical area of ​​the cell can move depending on the location of the mobile base station (such as the quadcopter 220).

[0040] Within RAN 200, a cell may include UEs capable of communicating with one or more sectors of each cell. Furthermore, each base station 210, 212, 214, 218, and 220 may be configured to provide access to the core network 102 for all UEs within the corresponding cell (see [link to core network 102]). Figure 1 Access points. For example, UEs 222 and 224 can communicate with base station 210; UEs 226 and 228 can communicate with base station 212; UEs 230 and 232 can communicate with base station 214 via RRH 216; UE 234 can communicate with base station 218; and UE 236 can communicate with mobile base station 220. In some examples, UEs 222, 224, 226, 228, 230, 232, 234, 236, 238, 240 and / or 242 can communicate with the access points described above and in... Figure 1 The UE / scheduled entity 106 shown is the same.

[0041] In some examples, a mobile network node (e.g., quadcopter 220) can be configured to act as a UE. For example, quadcopter 220 can operate within cell 202 by communicating with base station 210.

[0042] In a further aspect of RAN 200, sidelink signals can be used between UEs without relying on scheduling or control information from a base station. For example, two or more UEs (e.g., UEs 226 and 228) can communicate with each other using peer-to-peer (P2P) or sidelink signal 227 without relaying the communication through a base station (e.g., base station 212). In a further example, UE 238 is shown communicating with UEs 240 and 242. Here, UE 238 can act as a scheduling entity or a primary sidelink device, and UEs 240 and 242 can act as scheduled entities or non-primary (e.g., secondary) sidelink devices. In yet another example, the UE can act as a scheduling entity in a device-to-device (D2D), peer-to-peer (P2P), or vehicle-to-vehicle (V2V) network, and / or a mesh network. In the mesh network example, UEs 240 and 242 can optionally communicate directly with each other in addition to communicating with scheduling entity 238. Therefore, in a wireless communication system with scheduled access to time-frequency resources and with cellular, P2P, or mesh configurations, the scheduling entity and one or more scheduled entities can use the scheduled resources to communicate.

[0043] In the radio access network 200, the ability of a UE to communicate independently of its location while on the move is referred to as mobility. The various physical channels between the UE and the radio access network are generally used in the Access and Mobility Management Function (AMF, not shown). Figure 1 The AMF is established, maintained, and released under the control of the core network 102 (part of the core network). The AMF may include the Security Context Management Function (SCMF) for managing the security contexts of both the control plane and user plane, and the Security Anchor Function (SEAF) for performing authentication.

[0044] In various aspects of this disclosure, radio access network 200 may utilize DL-based mobility or UL-based mobility to achieve mobility and handover (i.e., the UE's connection is transferred from one radio channel to another). In a network configured for DL-based mobility, during a call with a scheduling entity, or at any other time, the UE may monitor various parameters of the signal from its serving cell and various parameters of neighboring cells. Depending on the quality of these parameters, the UE may maintain communication with one or more of the neighboring cells. During this time, if the UE moves from one cell to another, or if the signal quality from a neighboring cell exceeds the signal quality from the serving cell for a given amount of time, the UE may perform a handover or handover from the serving cell to a neighboring (target) cell. For example, UE 224 (shown as a vehicle, but any suitable form of UE may be used) may move from a geographic area corresponding to its serving cell 202 to a geographic area corresponding to a neighboring cell 206. When the signal strength or quality from neighboring cell 206 exceeds the signal strength or quality from its serving cell 202 for a given amount of time, UE 224 may send a report message indicating this condition to its serving base station 210. In response, UE 224 may receive a handover command, and the UE may undergo a handover to cell 206.

[0045] In a network configured for UL-based mobility, a UL reference signal from each UE can be used by the network to select a serving cell for each UE. In some examples, base stations 210, 212, and 214 / 216 can broadcast unified synchronization signals (e.g., unified primary synchronization signal (PSS), unified secondary synchronization signal (SSS), and unified physical broadcast channel (PBCH)). UEs 222, 224, 226, 228, 230, and 232 can receive the unified synchronization signal, derive the carrier frequency and time slot timing from it, and transmit uplink pilots or reference signals in response to the derived timing. The uplink pilot signal transmitted by a UE (e.g., UE 224) can be received concurrently by two or more cells (e.g., base stations 210 and 214 / 216) within the radio access network 200. Each cell can measure the strength of the pilot signal, and the radio access network (e.g., one or more of base stations 210 and 214 / 216 and / or a central node within the core network) can determine the serving cell for UE 224. When UE 224 moves through radio access network 200, the network can continue to monitor the uplink pilot signal transmitted by UE 224. When the signal strength or quality of the pilot signal measured by a neighboring cell exceeds the signal strength or quality measured by the serving cell, network 200 can, with or without notification to UE 224, hand over UE 224 from the serving cell to that neighboring cell.

[0046] Although the synchronization signal transmitted by base stations 210, 212, and 214 / 216 can be uniform, it does not necessarily identify a specific cell. Instead, it can identify an area of ​​multiple cells operating on the same frequency and / or with the same timing. Using areas in 5G networks or other next-generation communication networks enables an uplink-based mobility framework and improves the efficiency of both the UE and the network, as the number of mobility messages that need to be exchanged between the UE and the network can potentially be reduced.

[0047] In various implementations, the air interface in the radio access network 200 can utilize licensed spectrum, unlicensed spectrum, or shared spectrum. Licensed spectrum generally provides exclusive use of a portion of the spectrum by means of a mobile network operator that has purchased a license from a government regulatory agency. Unlicensed spectrum provides shared use of a portion of the spectrum without a government-authorized license. For example, 5G NR-based access to unlicensed spectrum (NR-U) can use unlicensed spectrum, such as the 5GHz and 6GHz bands. While some technical rules generally still need to be followed to access unlicensed spectrum, any operator or device can obtain access. Shared spectrum can fall between licensed and unlicensed spectrum, where technical rules or restrictions may be required to access the spectrum, but the spectrum may still be shared by multiple operators and / or multiple RATs. For example, a licensee of a portion of licensed spectrum can provide license-shared access (LSA) to share that spectrum with other parties, for example, by obtaining access using conditions determined by a suitable licensee.

[0048] The air interface in the radio access network 200 can utilize one or more duplex algorithms. Duplex refers to a point-to-point communication link where both endpoints can communicate with each other in both directions. Full-duplex means that both endpoints can communicate with each other simultaneously. Half-duplex means that only one endpoint can send information to the other endpoint at a time. In a wireless link, a full-duplex channel generally relies on the physical isolation of the transmitter and receiver, as well as appropriate interference cancellation techniques. Full-duplex simulation for wireless links is typically achieved using Frequency Division Duplex (FDD) or Time Division Duplex (TDD). In FDD, transmissions in different directions operate at different carrier frequencies. In TDD, transmissions in different directions on a given channel are separated using time division multiplexing. That is, at some times, the channel is dedicated to transmission in one direction, and at other times, the channel is dedicated to transmission in the other direction, where the direction can change very rapidly, for example, several times per time slot.

[0049] The air interface in the radio access network 200 can utilize one or more multiplexing and multiple access algorithms to enable simultaneous communication between individual devices. For example, the 5G NR specification utilizes Orthogonal Frequency Division Multiplexing (OFDM) with a Cyclic Prefix (CP) to provide multiple access for UL transmissions from UEs 222 and 224 to base station 210, and to provide multiplexing for DL ​​transmissions from base station 210 to one or more UEs 222 and 224. Additionally, for UL transmissions, the 5G NR specification provides support for Discrete Fourier Transform Extended OFDM (DFT-s-OFDM) with CP (also known as Single-Carrier FDMA (SC-FDMA)). However, within the scope of this disclosure, multiplexing and multiple access are not limited to the above schemes and can be provided using Time Division Multiple Access (TDMA), Code Division Multiple Access (CDMA), Frequency Division Multiple Access (FDMA), Sparse Code Multiple Access (SCMA), Resource Extended Multiple Access (RSMA), or other suitable multiple access schemes. In addition, multiplexing of DL transmissions from base station 210 to UEs 222 and 224 can be provided using time division multiplexing (TDM), code division multiplexing (CDM), frequency division multiplexing (FDM), orthogonal frequency division multiplexing (OFDM), sparse code multiplexing (SCM), or other suitable multiplexing schemes.

[0050] In downlink (DL) transmission, the transmitting device (e.g., scheduling entity 108) may allocate one or more resource elements (REs) (e.g., time, frequency, and / or spatial resources) to carry DL control information 114 to one or more scheduled entities 106. This DL control information 114 includes one or more DL control channels, typically carrying information originating from higher layers, such as the Physical Broadcast Channel (PBCH), Physical Downlink Control Channel (PDCCH), etc. Additionally, DL REs may be allocated to carry DL physical signals, which typically do not carry information originating from higher layers. These DL physical signals may include a primary synchronization signal (PSS); a secondary synchronization signal (SSS); a demodulation reference signal (DM-RS); a phase tracking reference signal (PT-RS); a channel state information reference signal (CSI-RS); and so on. The PDCCH may carry downlink control information (DCI) for one or more UEs in the cell. This may include, but is not limited to, power control commands, scheduling information, grants, and / or the assignment of REs for DL ​​and UL transmission.

[0051] In UL transmission, the transmitting device (e.g., the scheduled entity 106) can use one or more REs to carry UL control information 118 (UCI). The UCI can be initiated from a higher layer to the scheduling entity 108 via one or more UL control channels (such as the Physical Uplink Control Channel (PUCCH), Physical Random Access Channel (PRACH), etc.). Furthermore, the UL RE can carry UL physical signals, which typically do not carry information originating from higher layers, such as demodulation reference signals (DM-RS), phase tracking reference signals (PT-RS), sounding reference signals (SRS), etc. In some examples, the control information 118 may include a scheduling request (SR), i.e., a request to the scheduling entity 108 to schedule uplink transmission. Here, in response to an SR transmitted on control channel 118, the scheduling entity 108 can send downlink control information 114 indicating resources that can be scheduled for uplink packet transmission.

[0052] UL control information may also include Hybrid Automatic Repeat Request (HARQ) feedback, such as Acknowledgment (ACK) or Negative Acknowledgment (NACK), Channel State Information (CSI), or any other suitable UL control information. HARQ is a technique well-known to those skilled in the art, where the integrity of packet transmission can be checked at the receiving side to ensure accuracy, for example, using any suitable integrity checking mechanism, such as checksum or Cyclic Redundancy Check (CRC). If the integrity of the transmission is acknowledged, an ACK can be sent; otherwise, a NACK can be sent. In response to a NACK, the transmitting device can send a HARQ retransmission, which enables chase combining, incremental redundancy, etc.

[0053] In addition to control information, one or more REs can be allocated for user data or service data. Such services can be carried on one or more service channels, such as the Physical Downlink Shared Channel (PDSCH) for DL ​​transmissions, or the Physical Uplink Shared Channel (PUSCH) for UL transmissions.

[0054] To enable a UE to gain initial access to a cell, the RAN can provide system information (SI) characterizing the cell. This system information can be provided using minimum system information (MSI) and other system information (OSI). The MSI can be periodically broadcast on the cell to provide the most basic information required for initial cell access, as well as any OSIs that can be periodically broadcast or sent on demand. In some examples, the MSI can be provided through two different downlink channels. For example, the PBCH can carry a Master Information Block (MIB), and the PDSCH can carry System Information Block Type 1 (SIB1). In this art, SIB1 can be referred to as Residual Minimal System Information (RMSI). The OSI can include any SIs not broadcast in the MSI. In some examples, the PDSCH can carry multiple SIBs, not limited to SIB1 discussed above. Here, the OSI can be provided in these SIBs, for example, SIB2 and above.

[0055] The above description and in Figure 1 and Figure 2 The channels or carriers shown are not necessarily all channels or carriers that can be used between the scheduling entity 108 and the scheduled entity 106, and those skilled in the art will recognize that other channels or carriers, such as other service, control and feedback channels, may be used in addition to those shown.

[0056] These physical channels are typically multiplexed and mapped to transport channels for processing at the Media Access Control (MAC) layer. The transport channel carries blocks of information called transport blocks (TBs). The transport block size (TBS), which corresponds to the number of bits of information, can be a controlled parameter based on the modulation and decoding scheme (MCS) and the number of redundancies (RBs) in a given transmission.

[0057] Figure 3 This is a flowchart illustrating an example of a two-step RACH procedure according to some aspects of this disclosure. The two-step RACH procedure can be implemented as a contention-based RACH procedure or a contention-free RACH procedure. In this example, UE 302 is shown communicating with base station 304 using licensed or shared / unlicensed spectrum. When using shared or unlicensed spectrum, the UE can use a Listen-Before-Speak (LBT) procedure to determine whether another device is using the same spectrum before the UE sends a RACH message. It should be understood that aspects of this disclosure can be employed between the scheduled entity (e.g., UE 302) and the scheduling entity (e.g., base station 304 or gNB).

[0058] As shown in the figure, UE 302 sends a first message (e.g., MsgA 306) to base station 304. The MsgA 306 transmission may include both PRACH and PUSCH transmissions. The PRACH transmission may include a PRACH preamble sequence. In one example of a contention-based RACH procedure, the UE may select a PRACH preamble sequence from a set of available preamble sequences. In another example of a contention-free RACH procedure, base station 304 may assign a PRACH preamble to the UE. In some examples, the MsgAPUSCH transmission may include a Radio Network Temporary Identifier (RNTI) and / or other information. In some examples, the PUSCH may include information associated with a UE-specific Cell RNTI (C-RNTI). Base station 304 may use the C-RNTI in subsequent transmissions addressed to UE 302. For example, the base station may scramble the UE's PDCCH with a UE-specific C-RNTI.

[0059] When base station 304 receives MsgA 306, it detects the PRACH preamble in step 308. If the MsgA 306 received by base station 304 includes PUSCH information, base station 304 can decode the PUSCH in step 308. In some cases, the UE may fail to send the PUSCH due to invalid PUSCH resources (e.g., PUSCH timing) and / or Listen-After-Talk (LTB) failure, for example, in shared spectrum applications. In response to MsgA 306, base station 304 can send a second message (e.g., MsgB 310) to UE 302 in this two-step RACH procedure. MsgB 310 may include, for example, a Random Access Response (RAR). In a contention-based RACH example, MsgB 310 may also include a contention resolution message in the PDSCH.

[0060] The UE can monitor the PDCCH for a RAR that can be identified by the RNTI. In one example, the RNTI can be the MsgB-RNTI, which can be determined or calculated based on the resources (e.g., PRACH timing) that the UE uses to transmit MsgA 306. The PRACH timing is the time-frequency resource allocated by the network for transmitting PRACH. In another example, the RNTI can be the C-RNTI when C-RNTI information (e.g., the C-RNTI or information from which the C-RNTI can be derived) is included in the MsgA PUSCH transmission. For example, if the base station receives C-RNTI information in MsgA 306, the PDCCH in MsgB 310 can include CRC bits scrambled with the UE-specific C-RNTI. MsgB 310 can also include messages transmitted in the PDSCH. The messages sent in the PDSCH may include UE-specific content, such as indications of PRACH preamble confirmation, timing advance values, backoff indicators, contention resolution messages, transmit power control (TPC) commands, uplink or downlink resource grants, and / or other information. Upon receiving the second message (MsgB 310), UE 302 attempts to decode the PDCCH and PDSCH in step 312.

[0061] In one example, UE 302 and base station 304 can generate a device-specific network identifier (e.g., C-RNTI) associated with the UE based on the UE's identifier (UE ID). For example, the UE and base station can utilize a predetermined number of bits from the UE identifier (UE ID) as the device-specific network identifier, or derive the device-specific network identifier from a predetermined number of bits from the UE ID. See again. Figure 3 When UE 302 includes a UE ID or at least a portion thereof in the first message 306, base station 304 may determine the device-specific network identifier (e.g., C-RNTI) based on the UE ID in the same manner as UE 302 determines the device-specific network identifier (e.g., C-RNTI) based on the UE ID. In this way, both entities can know the device-specific network identifier that will be associated with UE 302.

[0062] In another example, UE 302 and base station 304 may generate a device-specific network identifier (e.g., C-RNTI) based on one or more resource parameters associated with the resources used to transmit the first message 306. For example, resource parameters associated with the resources used to transmit the first message (Msg A 306) may include transmission time, frequency, preamble sequence (e.g., root, shift), etc. UE 302 and base station 304 may utilize one or more of these resource parameters to generate a device-specific network identifier for use by UE 302 as part of a random access procedure.

[0063] In another example, UE 302 and base station 304 can generate a device-specific network identifier (e.g., C-RNTI) based on at least a portion of the UE ID and a combination of one or more resource parameters associated with the resource selected for transmitting the first message 306. For example, the UE-specific network identifier can be generated by mapping at least a portion of the UE ID and one or more resource parameters associated with the resource selected for transmitting the first message 306 to a device-specific network identifier. In this example, the resource for transmitting the first message 306 can be randomly selected, similar to the reference... Figure 3 Example as described. Alternatively, one or more resource parameters for sending the first message 306 can be selected based on a predetermined number of bits from the UE ID. Additional bits of the UE ID can also be sent in the first message 306. Using the UE ID payload and one or more resource parameters associated with the resources used to send the first message 306, UE 302 and base station 304 can derive a device-specific network identifier unique to UE 302.

[0064] When the aforementioned two-step RACH procedure is used with unlicensed or shared spectrum, there is a possibility that a PRACH may be sent when the PUSCH for MsgA is not sent, due to factors such as invalid PUSCH resources and / or Listen-After-Talk (LBT) failure. In this case, if the UE fails to send the PUSCH for MsgA, the UE may not monitor the PDCCH for MsgB (e.g., DCI format 1_0 with a CRC scrambled by C-RNTI). In some examples, when the UE fails to send the PUSCH for MsgA in a contention-based two-step RACH procedure (CBRA), the UE may not monitor the PDCCH for MsgB. When the UE does not send or fails to send the MsgAPUSCH including C-RNTI information, the base station (e.g., gNB) may not be able to obtain the UE's C-RNTI during the MsgA transmission. As a result, the base station may send a random access response with a CRC scrambled by the UE's C-RNTI in the PDCCH for MsgB.

[0065] However, the above scenario may not apply to the two-step contention-free RACH procedure (CFRA) that can be used in 5G NR networks. In CFRA, the network (e.g., the base station) can assign different PRACH preambles to different UEs to avoid PRACH collisions. In this case, even if the UE fails to send the MsgA PUSCH, the base station (e.g., the gNB) may still be able to determine the identifier of the UE that has successfully sent only the PRACH preamble. As a result, even if the UE fails to send C-RNTI information in MsgA, the base station can still send a random access response scrambled by the UE's C-RNTI.

[0066] This disclosure provides various options for configuring UE behavior in a two-step RACH procedure using either a contention-free RACH procedure (CFRA) or a contention-based RACH procedure (CBRA).

[0067] In one example, the UE monitors the MsgB PDCCH of the Random Access Response (RAR) identified by the C-RNTI only if the UE has actually sent a MsgA PUSCH including C-RNTI information (e.g., a C-RNTI MAC (control element) CE). If the UE has not sent C-RNTI information, the UE can monitor the Random Access Response identified by the MsgB-RNTI. In some examples, the UE can monitor the RAR in a special cell (SpCell), which may correspond to the primary cell of the Primary Cell Group (MSG) or the primary / secondary cell of the Secondary Cell Group (SCG), depending on whether the MAC entity is associated with the MCG or SCG.

[0068] This UE behavior can be used when the UE is operating in licensed and / or unlicensed spectrum. In licensed spectrum operation, PUSCH resources may be invalid or unavailable for PUSCH transmission. As a result, the UE only transmits PRACH and not PUSCH. In unlicensed spectrum operation, the UE may not transmit MsgA PUSCH, for example, due to invalid PUSCH resources and / or LBT failure for PUSCH transmission. In CBRA applications, UE overhead can be reduced by not monitoring MsgA PDCCH scrambled with C-RNTI. However, in CFRA applications, if the UE does not monitor MsgA PDCCH, the UE may not receive RAR identified by PDCCH scrambled with C-RNTI when the base station can determine C-RNTI even if the UE does not transmit MsgAPUSCH.

[0069] In another example, the UE monitors the MsgB PDCCH of SpCell for a random access response identified by the C-RNTI, as long as the UE includes C-RNTI information (e.g., C-RNTI MAC CE) in the data it sends as the MsgA PUSCH, regardless of whether the UE actually sends a PUSCH including the C-RNTI information (e.g., due to LBT failure or invalid PUSCH resources). In CFRA applications, this implementation allows the UE to receive RAR within a PDCCH scrambled with the C-RNTI, even if the UE has not yet sent the MsgA PUSCH. However, in CBRA applications, the UE may not need to monitor a PDCCH scrambled with the C-RNTI, because the base station cannot send a PDCCH scrambled with the C-RNTI without receiving the C-RNTI information in the MsgA. In one example, as a UE implementation, the UE can choose not to monitor a PDCCH scrambled with the C-RNTI when the UE has not actually sent the MsgA PUSCH including the C-RNTI MAC CE. In this scenario, not monitoring the PDCCH should not have a significant impact, because regardless of whether the UE sends its C-RNTI information (e.g., C-RNTI MAC CE), the base station (e.g., gNB) will be unable to send the PDCCH scrambled by the C-RNTI.

[0070] In another example, the UE may behave differently in CBRA and CFRA. In CBRA, the UE monitors the SpCell PDCCH for the Random Access Response (RAR) identified by the C-RNTI only if the UE has actually sent the MsgA PUSCH including the C-RNTI MAC CE. In CFRA, the UE monitors the PDCCH identified by the C-RNTI, regardless of whether the MsgA PUSCH was sent successfully or not. For example, the UE may include the C-RNTI information for transmission in the MsgA PUSCH, but for the reasons mentioned above, the UE may only send the MsgA PRACH portion if the PUSCH does not include C-RNTI information.

[0071] In another example, the base station (e.g., gNB) can configure different UE PDCCH monitoring behaviors in various configurations. In one example, even when the UE fails to send the MsgA PUSCH for CFRA, the base station can configure the UE to monitor the MsgB PDCCH identified by the C-RNTI. In another example using CBRA, when the base station intends to send a Random Access Response (RAR) identified by the C-RNTI, the base station can configure the UE to monitor the MsgB PDCCH identified by the C-RNTI. In this example, the base station can obtain knowledge of the UE's C-RNTI through MsgA PUSCH detection or the timing of the PRACH used to send MsgA. In another example, if the base station does not configure the UE to monitor the PDCCH identified by the C-RNTI, the UE can alternatively monitor the MsgB-RNTI in the PDCCH. In some examples, this configuration can be specific to UEs using shared spectrum or UEs using both licensed and shared spectrum. This configuration can also restrict the use of PDCCH C-RNTI monitoring for certain RACH events (e.g., handover, beam failure recovery (BFR)) and / or radio conditions (e.g., when the reference signal received power (RSRP) is above a predetermined threshold and / or for certain beams).

[0072] Figure 4 This is a block diagram illustrating an example of a hardware implementation of a scheduling entity 400 employing a processing system 414. For example, the scheduling entity 400 may be as shown in... Figure 1 and / or Figure 2 The user equipment (UE) shown in any one or more of the examples. In another example, the scheduling entity 400 may be as shown in... Figure 1 , Figure 2 and / or Figure 3 Any one or more of the base stations shown.

[0073] The scheduling entity 400 may be implemented using a processing system 414 including one or more processors 404. Examples of processors 404 include microprocessors, microcontrollers, digital signal processors (DSPs), field-programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gate logic, discrete hardware circuitry, and other suitable hardware configured to perform the various functionalities described throughout this disclosure. In various examples, the scheduling entity 400 may be configured to perform any one or more of the functions described herein. That is, the processor 404 utilized in the scheduling entity 400 may be used to implement any one or more of the processes and procedures described and shown in the included figures.

[0074] In this example, processing system 414 can be implemented with a bus architecture typically represented by bus 402. Depending on the specific application and overall design constraints of processing system 414, bus 402 can include any number of interconnect buses and bridges. Bus 402 communicatively couples together various circuits including one or more processors (typically represented by processor 404), memory 405, and computer-readable media (typically represented by computer-readable media 406). Bus 402 can also link various other circuits, such as timing sources, peripherals, pressure regulators, and power management circuits, which are well known in the art and therefore will not be described further. Bus interface 408 provides an interface between bus 402 and transceiver 410. Transceiver 410 provides a communication interface or component for communicating with various other devices over a transmitting medium. Depending on the characteristics of the device, a user interface 412 (e.g., keypad, display, speaker, microphone, joystick) may also be provided. Of course, such a user interface 412 is optional and may be omitted in some examples (such as base stations).

[0075] In some aspects of this disclosure, processor 404 may include circuitry configured for various functions (e.g., random access procedures). For example, the circuitry may be configured to implement throughout this disclosure, including... Figures 3 to 7 The circuit system may include one or more of the functions described in the accompanying drawings. The circuit system may include processing circuitry 440 and communication circuitry 442. Processing circuitry 440 may be configured to perform various data processing functions and algorithms, including those for implementing the various concepts and designs described in this disclosure. Communication circuitry 442 may be configured to perform various communication functions and algorithms, including those for implementing the various concepts and designs described in this disclosure.

[0076] Processor 404 is responsible for managing bus 402 and general processing, including the execution of software stored on computer-readable medium 406. When executed by processor 404, the software causes processing system 414 to perform various functions described below for any particular device. Computer-readable medium 406 and memory 405 may also be used to store data manipulated by processor 404 during software execution.

[0077] One or more processors 404 in the processing system can execute software. Software should be broadly interpreted as instructions, instruction sets, code, code segments, program code, programs, subroutines, software modules, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether described using terms such as software, firmware, middleware, microcode, hardware description languages, or other terms. Software may reside on a computer-readable medium 406. The computer-readable medium 406 may be a non-transitory computer-readable medium. As examples, non-transitory computer-readable media include magnetic storage devices (e.g., hard disks, floppy disks, magnetic tapes), optical discs (e.g., compact discs (CDs) or digital universal discs (DVDs)), smart cards, flash memory devices (e.g., cards, sticks, or key drives), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, and any other suitable media for storing software and / or instructions that can be accessed and read by a computer. Computer-readable medium 406 may reside in processing system 414, be external to processing system 414, or be distributed across multiple entities including processing system 414. Computer-readable medium 406 may be implemented in a computer program product. As an example, a computer program product may include a computer-readable medium within encapsulation material. Those skilled in the art will recognize how the functionality described throughout this disclosure is best implemented depending on the specific application and the overall design constraints imposed on the system as a whole.

[0078] In one or more examples, computer-readable storage medium 406 may include software configured for various functions (e.g., processing instructions 452 and communication instructions 454). For example, the software may be configured to implement throughout this disclosure with respect to the included drawings (e.g., Figures 3 to 7 () describes one or more of the functions of the random access procedure.

[0079] Figure 5 This is a conceptual diagram illustrating an example hardware implementation of an exemplary scheduled entity 500 using a processing system 514. According to various aspects of this disclosure, an element, any part of an element, or any combination of elements can be implemented using a processing system 514 including one or more processors 504. For example, the scheduled entity 500 can be as follows: Figure 1 , Figure 2 and / Figure 3 Any one or more of the user equipment (UE) shown.

[0080] Processing system 514 can be with Figure 4The processing system 414 shown is essentially the same, including a bus interface 508, a bus 502, a memory 505, a processor 504, and a computer-readable medium 506. Furthermore, the scheduled entity 500 may include a user interface 512 and a transceiver 510, which are similar to those described above. Figure 4 The processes described herein are substantially the same. That is, the processor 504 used in the scheduled entity 500 can be used to implement any one or more of the processes described in this disclosure and shown in the included figures. In some aspects of this disclosure, the processor 504 may include circuitry configured for various functions. For example, the circuitry may be configured to implement one or more of the functions described in this disclosure with respect to the included figures. The circuitry may include processing circuitry 540 and communication circuitry 542. Processing circuitry 540 may be configured to perform various data processing functions and algorithms for the random access procedure, including those functions and algorithms for implementing the various concepts and designs described in this disclosure. Communication circuitry 542 may be configured to perform various functions and algorithms for wireless communication and the random access procedure. In one or more examples, computer-readable storage medium 506 may include software configured for various functions (e.g., processing instructions 552 and communication instructions 554). For example, the software may be configured to implement one or more of the functions and algorithms of the random access procedure described in this disclosure with respect to the included figures.

[0081] Figure 6 This is a flowchart illustrating an exemplary process 600 for a two-step random access procedure according to some aspects of this disclosure. As described below, within the scope of this disclosure, some or all of the illustrated features may be omitted in certain implementations, and some illustrated features may not be necessary for implementing all embodiments. In some examples, process 600 may be... Figure 5 The scheduled entity 500 shown is executed. In some examples, process 600 may be executed by any suitable means or component for performing the functions or algorithms described below.

[0082] In box 602, the scheduled entity (e.g., UE 302) sends a first message to the scheduling entity. The first message includes a Physical Random Access Channel (PRACH) preamble sequence for a random access procedure. For example, the scheduled entity may use processing circuitry 540 to prepare data to be included in the first message. For example, the first message may be MsgA 306 for a two-step random access procedure. The first message may also include a PUSCH containing information for determining the device-specific network identifier (PUSCH) of the scheduled entity. In one example, the PUSCH may be a C-RNTI or other suitable PUSCH. In one example, the first message may include a C-RNTI MAC CE. However, in some cases, even if the scheduled entity has included the C-RNTI MAC CE information in the data to be sent as the first message, the scheduled entity may fail to send the C-RNTI MAC CE in the PUSCH of the first message (e.g., due to LBT failure or invalid PUSCH resources). The scheduled entity can use communication circuit 542 to send the first message via transceiver 510 using communication resources allocated for the random access procedure (e.g., PRACH timing and PUSCH timing).

[0083] In box 604, if the first message includes information for determining the device-specific network identifier (e.g., C-RNTI) of the scheduled entity, the scheduled entity monitors the physical downlink control channel (PDCCH) of the second message in response to the first message from the scheduling entity. The second message may be scrambled by the device-specific network identifier of the scheduled entity. For example, the second message may be MsgB 310 of a two-step random access procedure. The scheduled entity may use communication circuitry 542 to monitor the PDCCH of the second message via transceiver 510.

[0084] In one example, if the scheduled entity has actually sent a PUSCH that includes C-RNTI MAC CE, the scheduled entity can determine that the first message includes C-RNTI information.

[0085] Figure 7 This is a flowchart illustrating an exemplary process 700 for a two-step random access procedure according to some aspects of this disclosure. As described below, some or all of the illustrated features may be omitted in certain implementations within the scope of this disclosure, and some illustrated features may not be necessary for implementing all embodiments. In some examples, process 700 may be... Figure 5 The scheduled entity 500 shown is executed. In some examples, process 700 may be executed by any suitable means or component for performing the functions or algorithms described below.

[0086] In block 702, the scheduled entity (e.g., UE 302) sends a first message to the scheduling entity. The first message includes a Physical Random Access Channel (PRACH) preamble sequence for the random access procedure. For example, the scheduled entity may use processing circuitry 540 to prepare data to be sent as the first message. For example, the first message may be MsgA 306 for a two-step random access procedure. The first message may also include a PUSCH containing information for determining the device-specific network identifier (DPI) of the scheduled entity. In one example, the DPI may be a C-RNTI or other suitable DPI. In one example, the data to be sent as the first message may include a C-RNTI MAC CE. The scheduled entity may use communication circuitry 542 to send the first message via transceiver 510 using communication resources allocated for the random access procedure (e.g., PRACH timing and PUSCH timing). However, in some cases, the scheduled entity may fail to send the C-RNTI information in the PUSCH of the first message.

[0087] In block 704, the scheduled entity monitors the Physical Downlink Control Channel (PDCCH) of the second message in response to the first message from the scheduling entity, regardless of whether the first message includes information for determining the device-specific network identifier (e.g., C-RNTI) of the scheduled entity. For example, the scheduled entity may include C-RNTI information in the PUSCH data for transmission of the first message. In this case, the scheduled entity may successfully transmit the PRACH portion of the first message, but fails to transmit the PUSCH including the C-RNTI information due to invalid PUSCH resources and / or LBT failure. In one example, the scheduled entity monitors the PDCCH of the second message regardless of whether the first message includes a C-RNTI MAC CE for determining the device-specific network identifier of the scheduled entity. The second message may be scrambled by the device-specific network identifier of the scheduled entity. For example, the second message may be MsgB 310 of a two-step random access procedure. The scheduled entity may use communication circuitry 542 to monitor the PDCCH of the second message via transceiver 510.

[0088] Figure 8 This is a flowchart illustrating an exemplary process 800 for a two-step random access procedure according to some aspects of this disclosure. As described below, some or all of the illustrated features may be omitted in certain implementations within the scope of this disclosure, and some illustrated features may not be necessary for implementing all embodiments. In some examples, process 800 may be... Figure 5 The scheduled entity 500 shown is executed. In some examples, process 800 may be executed by any suitable means or component for performing the functions or algorithms described below.

[0089] In box 802, the scheduled entity (e.g., UE 302) receives configuration information from the scheduling entity (e.g., base station 304) for configuring the scheduled entity in relation to a random access procedure. The configuration information configures the behavior of the scheduled entity during the random access procedure. For example, the scheduled entity may use communication circuitry 542 to receive the configuration information via transceiver 510. In one example, the configuration information may be included in radio resource control (RRC) configuration received from the scheduling entity (e.g., base station 304).

[0090] In block 804, the scheduled entity sends a first message for the random access procedure to the scheduling entity. The first message includes at least a Physical Random Access Channel (PRACH) preamble sequence for the random access procedure. For example, the first message may be a first message for a two-step random access procedure (e.g., MsgA 306). In one example, the scheduled entity may use processing circuitry 540 to prepare data to be sent as the first message. The scheduled entity may use communication circuitry 542 to send the first message via transceiver 510 using communication resources allocated for the random access procedure (e.g., PRACH timing and PUSCH timing). The first message may or may not include information used to determine the device-specific network identifier of the scheduled entity. For example, the scheduled entity may include C-RNTI MAC CE in the data to be sent as the first message. However, in some cases, such as due to invalid PUSCH resources and / or LBT failure in the shared spectrum, the scheduled entity may fail to send C-RNTI MAC CE in the PUSCH of the first message.

[0091] In block 806, the scheduled entity monitors the PDCCH of a second message in response to the first message based on configuration information. For example, the scheduled entity can use communication circuitry 542 to monitor the PDCCH of the second message, which may be scrambled by the scheduled entity's device-specific network identifier (e.g., C-RNTI) or MsgB-RNTI. For example, the second message may be a MsgB 310 with a two-step random access procedure. The scheduled entity can use communication circuitry 542 to monitor the PDCCH of the second message via transceiver 510.

[0092] In one example, the configuration information can configure the scheduled entity to monitor the PDCCH of a second message scrambled by the scheduled entity’s device-specific network identifier, regardless of whether the first message sent actually includes information for determining the device-specific network identifier (e.g., C-RNTI) of the scheduled entity (e.g., C-RNTI MAC CE).

[0093] In one example, configuration information may configure a scheduled entity to monitor the PDCCH of a second message scrambled by the scheduled entity's device-specific network identifier (e.g., C-RNTI) based on at least one of the following: the type of random access procedure (e.g., CBRA or CFRA), a predetermined event of the random access procedure, the spectrum used to transmit the first transmission, or radio conditions between the scheduled entity and the scheduling entity. Examples of predetermined events of the random access procedure may include handover and beam failure recovery. In some examples, the configuration information may be used only for CBRA. In some examples, the configuration information may be used for licensed and shared spectrum situations.

[0094] In one configuration, the means 400 and / or 500 for wireless communication each include various components for performing the various functions, processes, and programs described in this disclosure. In one aspect, the aforementioned components may be... Figure 4 or Figure 5 The processor 404 / 504 shown is configured to perform the functions mentioned in the aforementioned components. In another aspect, the aforementioned components may be circuitry or any device configured to perform the functions mentioned in the aforementioned components.

[0095] Of course, in the above examples, the circuitry included in processor 404 / 504 is provided merely as an example, and other components for performing the described functions may be included within various aspects of this disclosure, including but not limited to instructions stored in computer-readable storage medium 406 / 506, or... Figure 1 , Figure 2 And / or any of 3, as described and utilized, for example, in this article regarding Figure 3 , Figure 6 and / or Figure 7 Any other suitable device or component of the described process and / or algorithm.

[0096] Several aspects of wireless communication networks have been presented with reference to exemplary implementations. As will be readily understood by those skilled in the art, the various aspects described herein can be extended to other telecommunications systems, network architectures, and communication standards.

[0097] As examples, these aspects can be implemented within other systems defined by 3GPP, such as Long Term Evolution (LTE), Evolved Packet System (EPS), Universal Mobile Telecommunications System (UMTS), and / or Global System for Mobile Communications (GSM). These aspects can also be extended to systems defined by 3GPP2 (3GPP2), such as CDMA2000 and / or Evolved Data Optimized (EV-DO). Other examples can be implemented within systems employing IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Ultra Wideband (UWB), Bluetooth, and / or other suitable systems. The actual telecommunications standards, network architecture, and / or communication standards employed will depend on the specific application and the overall design constraints imposed on the system.

[0098] Within this disclosure, the term “exemplary” is used to mean “serving as an example, instance, or illustration.” Any implementation or aspect described herein as “exemplary” is not necessarily to be construed as superior to or better than other aspects of this disclosure. Similarly, the term “aspect” does not require that all aspects of this disclosure include the features, advantages, or modes of operation discussed. The term “coupled” is used herein to refer to direct or indirect coupling between two objects. For example, if object A physically contacts object B, and object B contacts object C, then objects A and C can still be considered coupled to each other—even if they are not in direct physical contact. For example, a first object can be coupled to a second object, even if the first object never directly contacts the second object. The terms “circuit” and “circuit system” are used broadly and are intended to include both hardware implementations of electronic devices and conductors, and software implementations of information and instructions, which, when connected and configured, enable the performance of the functions described in this disclosure without limitation on the type of electronic circuit, and which, when executed by a processor, enable the performance of the functions described in this disclosure.

[0099] Figures 1 to 7 One or more of the components, steps, features, and / or functions shown may be rearranged and / or combined into a single component, step, feature, or function, or may be implemented in several components, steps, or functions. Additional elements, components, steps, and / or functions may also be added without departing from the novel features disclosed herein. Figures 1 to 7 The apparatus, devices, and / or components shown can be configured to perform one or more of the methods, features, or steps described herein. The novel algorithms described herein can also be efficiently implemented in software and / or embedded in hardware.

[0100] It should be understood that the specific order or hierarchy of steps in the disclosed method is an illustration of an exemplary process. Based on design preferences, it should be understood that the specific order or hierarchy of steps in the method can be rearranged. The appended method claims present elements of various steps in a sample order and are not intended to be limited to the presented specific order or hierarchy, unless specifically stated herein.

[0101] The foregoing description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects. Therefore, the claims are not intended to be limited to the aspects shown herein, but are given the full scope consistent with the text of the claims, wherein, unless specifically stated otherwise, references to elements in the singular form are not intended to mean “one and only one,” but rather “one or more.” Unless otherwise expressly stated, the term “some” refers to one or more. The phrase “at least one” in the list of reference items means any combination of those items, including a single member. As an example, “at least one of a, b, or c” is intended to cover a; b; c; a and b; a and c; b and c; and a and b and c. All structural and functional equivalents of the elements throughout the various aspects described in this disclosure are expressly incorporated herein by reference and intended to be included by the claims, and are known or to be known by those skilled in the art. Furthermore, nothing disclosed herein is intended to be offered to the public, whether or not such disclosure is expressly stated in the claims.

Claims

1. A method for wireless communication at a scheduled entity, comprising: Receive configuration information from the scheduling entity for configuring the scheduled entity in relation to the random access procedure; Send a first message to the scheduling entity, which includes at least a sequence of Physical Random Access Channel (PRACH) preambles for the random access procedure; Based on the configuration information, the Physical Downlink Control Channel (PDCCH) of the second message in response to the first message is monitored. The configuration information configures the scheduled entity to: monitor the PDCCH of the second message scrambled by the device-specific network identifier (PSI) of the scheduled entity for a contention-free RACH (CFRA) procedure, even when the scheduled entity fails to send the Physical Uplink Shared Channel (PUSCH) of the first message; and configures the scheduled entity to: monitor the PDCCH of the second message scrambled by the PSI of the device-specific network identifier for a contention-based RACH (CBRA) procedure, when the scheduling entity intends to send the second message scrambled by the PSI obtained through detection via the first message PUSCH or PRACH timing.

2. The method according to claim 1, wherein, The configuration information configures the scheduled entity to further restrict monitoring of the PDCCH of the second message scrambled by the device-specific network identifier based on at least one of the type of random access procedure, a predetermined event of the random access procedure, or radio conditions between the scheduled entity and the scheduling entity.

3. A scheduled entity for wireless communication, comprising: Memory; as well as Processor, the processor being coupled to the memory, The processor is configured as follows: Receive configuration information from the scheduling entity for configuring the scheduled entity in relation to the random access procedure; Send a first message to the scheduling entity, which includes at least a sequence of Physical Random Access Channel (PRACH) preambles for the random access procedure; Based on the configuration information, the Physical Downlink Control Channel (PDCCH) in response to the second message in response to the first message is monitored. The configuration information configures the scheduled entity as follows: for a contention-free RACH procedure (CFRA), even when the scheduled entity fails to send the first message physical uplink shared channel (PUSCH), it monitors the PDCCH of the second message scrambled by the device-specific network identifier (PDCCH) of the scheduled entity; and for a contention-based RACH procedure (CBRA), when the scheduling entity intends to send the second message scrambled by the device-specific network identifier (PDCCH) obtained through the first message PUSCH detection or PRACH timing, it monitors the PDCCH of the second message scrambled by the device-specific network identifier (PDCCH).

4. The scheduled entity according to claim 3, wherein, The configuration information configures the scheduled entity to further restrict monitoring of the PDCCH of the second message scrambled by the device-specific network identifier based on at least one of the type of random access procedure, a predetermined event of the random access procedure, or radio conditions between the scheduled entity and the scheduling entity.

5. An apparatus for wireless communication performed at a scheduled entity, the apparatus comprising: A component for receiving configuration information from a scheduling entity for configuring the scheduled entity in relation to a random access procedure; A component for sending to the scheduling entity a first message comprising at least a Physical Random Access Channel (PRACH) preamble sequence for the random access procedure; A component used to monitor the Physical Downlink Control Channel (PDCCH) in response to a second message in response to the first message, based on the configuration information. The configuration information configures the scheduled entity as follows: for a contention-free RACH procedure (CFRA), even when the scheduled entity fails to send the first message physical uplink shared channel (PUSCH), it monitors the PDCCH of the second message scrambled by the device-specific network identifier (PDCCH) of the scheduled entity; and for a contention-based RACH procedure (CBRA), when the scheduling entity intends to send the second message scrambled by the device-specific network identifier (PDCCH) obtained through the first message PUSCH detection or PRACH timing, it monitors the PDCCH of the second message scrambled by the device-specific network identifier (PDCCH).

6. The apparatus according to claim 5, wherein, The configuration information configures the scheduled entity to further restrict monitoring of the PDCCH of the second message scrambled by the device-specific network identifier based on at least one of the type of random access procedure, a predetermined event of the random access procedure, or radio conditions between the scheduled entity and the scheduling entity.

7. A computer-readable medium having program code recorded thereon, wherein the program code is executable by one or more processors of a scheduled entity to cause the one or more processors to perform the method of claim 1 or 2.

Images