Discontinuous reception for two-step random access procedure

Abstract

A wireless device receives a response to a message comprising a preamble and a transport block during a discontinuous reception (DRX) active time of a DRX operation of the wireless device. The DRX active time is determined based on a time window of at least one symbol after a transmission occasion of the transport block.

Description

[0001] Divisional application

[0002] This application is a divisional application of the invention application filed on October 5, 2020, with application number 202080069461.8 and titled "Discontinuous reception for a two-step random access procedure".

[0003] Cross-reference to related applications

[0004] This application claims the benefit of U.S. Provisional Application No. 62 / 910,257, filed October 3, 2019, the entire contents of which are hereby incorporated by reference. Attached Figure Description

[0005] Examples of several embodiments of the various embodiments of this disclosure are described herein with reference to the accompanying drawings.

[0006] Figure 1A and Figure 1B An exemplary mobile communication network in which embodiments of the present disclosure may be implemented is shown.

[0007] Figure 2A and Figure 2B The new radio (NR) user plane and control plane protocol stacks are shown respectively.

[0008] Figure 3 It shows Figure 2A An example of the services provided between the protocol layers of the NR user plane protocol stack.

[0009] Figure 4A It shows the flow through Figure 2A An example downlink data stream of the NR user plane protocol stack.

[0010] Figure 4B An exemplary format of the MAC subheader in a MAC PDU is shown.

[0011] Figure 5A and Figure 5B The mappings between logical channels, transport channels, and physical channels used for downlink and uplink are shown respectively.

[0012] Figure 6 This is an example diagram illustrating the RRC state transition of the UE.

[0013] Figure 7 An exemplary configuration is shown in which OFDM symbols are grouped into NR frames.

[0014] Figure 8 An exemplary configuration of time slots in the time and frequency domains of an NR carrier is shown.

[0015] Figure 9 An example of bandwidth adaptation using three configured BWPs with NR carriers is shown.

[0016] Figure 10A Three carrier aggregation configurations with two component carriers are shown.

[0017] Figure 10B An example is shown of how aggregated cells can be configured into one or more PUCCH groups.

[0018] Figure 11A An example of the SS / PBCH block structure and location is shown.

[0019] Figure 11B An example of CSI-RS mapped in the time and frequency domains is shown.

[0020] Figure 12A and Figure 12B Examples of three downlink and uplink beam management procedures are shown respectively.

[0021] Figure 13A , Figure 13B and Figure 13C Four-step contention-based random access procedures, two-step contention-free random access procedures, and another two-step random access procedure are shown respectively.

[0022] Figure 14A An example of the CORESET configuration for the bandwidth portion is shown.

[0023] Figure 14B An example of CCE-to-REG mapping for DCI transport is shown on CORESET and PDCCH processing.

[0024] Figure 15 An example of a wireless device communicating with a base station is shown.

[0025] Figure 16A , Figure 16B , Figure 16C and Figure 16D An exemplary structure for uplink and downlink transmission is shown.

[0026] Figure 17A This is an example of the PRACH timing of an aspect of an exemplary embodiment of the present disclosure with respect to UL radio resources TDM.

[0027] Figure 17B This is an example of the PRACH timing of an aspect of an exemplary embodiment of the present disclosure with UL radio resources FDM.

[0028] Figure 17CThis is an example of the PRACH timing of UL radio resources TDM and FDM according to an exemplary embodiment of this disclosure.

[0029] Figure 18 An example of the ra-ssb-OccasionMaskIndex value for an aspect according to an exemplary embodiment of this disclosure is shown.

[0030] Figure 19A RARs of exemplary embodiments according to this disclosure are shown.

[0031] Figure 19B The MAC subheader of an aspect according to an exemplary embodiment of this disclosure is shown.

[0032] Figure 19C RARs of exemplary embodiments according to this disclosure are shown.

[0033] Figure 20 The MAC RAR format of an exemplary embodiment according to this disclosure is shown.

[0034] Figure 21 The RAR format of an exemplary embodiment according to this disclosure is shown.

[0035] Figure 22A The RAR format of an exemplary embodiment according to this disclosure is shown.

[0036] Figure 22B The RAR format of an exemplary embodiment according to this disclosure is shown.

[0037] Figure 23 This is a diagram illustrating a two-step RA procedure according to an exemplary embodiment of the present disclosure.

[0038] Figure 24A This is a diagram of a two-step RA procedure according to an exemplary embodiment of this disclosure.

[0039] Figure 24B This is a diagram of a two-step RA procedure according to an exemplary embodiment of this disclosure.

[0040] Figure 25 This is a diagram illustrating a two-step RA procedure according to an exemplary embodiment of the present disclosure.

[0041] Figure 26 A two-step RA procedure is shown according to an exemplary embodiment of this disclosure.

[0042] Figure 27 A two-step RA procedure is shown according to an exemplary embodiment of this disclosure.

[0043] Figure 28 DRX operation is illustrated in an exemplary embodiment according to this disclosure.

[0044] Figure 29A The active time of DRX operation according to an exemplary embodiment of this disclosure is shown.

[0045] Figure 29B The active time of DRX operation according to an exemplary embodiment of this disclosure is shown.

[0046] Figure 30A DRX operation is illustrated in an exemplary embodiment according to this disclosure.

[0047] Figure 30B DRX operation is illustrated in an exemplary embodiment according to this disclosure.

[0048] Figure 31 DRX operation is illustrated in an exemplary embodiment according to this disclosure.

[0049] Figure 32 DRX operation is illustrated in an exemplary embodiment according to this disclosure.

[0050] Figure 33 DRX operation is illustrated in an exemplary embodiment according to this disclosure.

[0051] Figure 34 DRX operation is illustrated in an exemplary embodiment according to this disclosure.

[0052] Figure 35 This is a flowchart of an exemplary embodiment according to this disclosure.

[0053] Figure 36 This is a flowchart of an exemplary embodiment according to this disclosure. Detailed Implementation

[0054] In this disclosure, various embodiments are presented as examples of how the disclosed techniques can be implemented and / or how they can be practiced in various environments and scenarios. It will be apparent to those skilled in the art that various changes in form and detail can be made therein without departing from the scope of the invention. Indeed, after reading this specification, it will be apparent to those skilled in the art how to implement alternative embodiments. Embodiments of the invention should not be limited to any of the described exemplary embodiments. Embodiments of this disclosure will be described with reference to the accompanying drawings. Limitations, features, and / or elements from the disclosed exemplary embodiments can be combined to create additional embodiments within the scope of this disclosure. Any drawings highlighting features and advantages are presented for illustrative purposes only. The disclosed architecture is flexible and configurable enough that it can be utilized in ways other than those shown. For example, any actions listed in the flowcharts can be reordered or optionally used only in certain embodiments.

[0055] The implementation scheme can be configured to operate as needed. The disclosed mechanisms can be executed when certain criteria are met, such as in wireless devices, base stations, radio environments, networks, combinations thereof, etc. Exemplary criteria may be based at least in part on, for example, wireless device or network node configuration, traffic load, initial system setup, packet size, service characteristics, combinations thereof, etc. Various exemplary implementation schemes can be applied when one or more criteria are met. Therefore, exemplary implementation schemes that selectively implement the disclosed protocols can be implemented.

[0056] A base station can communicate with a mixture of wireless devices. The wireless devices and / or base stations can support multiple technologies and / or multiple versions of the same technology. Wireless devices may have certain specific capabilities, depending on the type and / or capability of the wireless device. When this disclosure refers to a base station communicating with multiple wireless devices, this disclosure may refer to a subset of the total number of wireless devices in the coverage area. For example, this disclosure may refer to multiple wireless devices having a given capability and a given LTE or 5G version in a given sector of a base station. Multiple wireless devices in this disclosure may refer to a selected set of wireless devices, and / or a subset of the total number of wireless devices in the coverage area performing according to the disclosed method, etc. Multiple base stations or multiple wireless devices may exist in the coverage area that may not conform to the disclosed method; for example, these wireless devices or base stations may be based on older versions of LTE or 5G technology.

[0057] In this disclosure, “a” (“a” and “an”) and similar phrases will be interpreted as “at least one” and “one or more”. Similarly, any term ending with the suffix “(s)” will be interpreted as “at least one” and “one or more”. In this disclosure, the term “may” is interpreted as “may, for example”. In other words, the term “may” indicates that the statement following the term “may” is an example of one of a number of suitable possibilities that one or more embodiments in various implementations may or may not be adopted. As used herein, the terms “comprises” and “consists of” enumerate one or more components of the element being described. The term “comprises” is interchangeable with “includes” and does not exclude the inclusion of unlisted components in the element being described. In contrast, “consists of” provides a complete enumeration of the one or more components of the element being described. As used herein, the term “based on” should be interpreted as “at least partially based on”, rather than, for example, “based on only”. As used herein, the term “and / or” indicates any possible combination of the enumerated elements. For example, "A, B and / or C" can mean: A; B; C; A and B; A and C; B and C; or A, B and C.

[0058] If A and B are sets, and every element of A is also an element of B, then A is called a subset of B. In this specification, only non-empty sets and subsets are considered. For example, possible subsets of B = {cell1, cell2} are: {cell1}, {cell2}, and {cell1, cell2}. The phrase “based on” (or equivalently “at least based on”) indicates that the phrase following the term “based on” is an example of a suitable possibility among a variety of suitable possibilities that may or may not be used for one or more different implementations. The phrase “in response to” (or equivalently “at least in response to”) indicates that the phrase following the phrase “in response to” is an example of a suitable possibility among a variety of suitable possibilities that may or may not be used for one or more different implementations. The phrase “depends on” (or equivalently “at least depends on”) indicates that the phrase following the phrase “depends on” is an example of a suitable possibility among a variety of suitable possibilities that may or may not be used for one or more different implementations. The phrase “adopt / use” (or equivalently “at least adopt / use”) indicates that the phrase following “adopt / use” is an example of one of a variety of suitable possibilities that may or may not be used for one or more different implementation schemes.

[0059] The term "configurable" can refer to the capabilities of a device, whether the device is in an operational or non-operational state. "Configurable" can mean specific settings within the device that affect its operational characteristics, regardless of whether the device is in an operational or non-operational state. In other words, hardware, software, firmware, registers, memory values, etc., can be "configured" within the device to provide specific characteristics to the device, whether the device is in an operational or non-operational state. Similarly, the term "control messages generated in the device" can mean that the control messages have parameters that can be used to configure specific characteristics in the device or to implement certain actions in the device, regardless of whether the device is in an operational or non-operational state.

[0060] In this disclosure, a parameter (or equivalently referred to as a field or information element: IE) may include one or more information objects, and an information object may include one or more other objects. For example, if parameter (IE)N includes parameter (IE)M, and parameter (IE)M includes parameter (IE)K, and parameter (IE)K includes parameter (information element)J, then, for example, N includes K, and N includes J. In an exemplary embodiment, when one or more messages include multiple parameters, it means that a parameter among the multiple parameters is in at least one of the one or more messages, but not necessarily in every one of the one or more messages.

[0061] Many of the proposed features are described as optional by using the word "may" or parentheses. For brevity and readability, this disclosure does not explicitly describe every permutation that can be obtained by selecting from the group of optional features. This disclosure should be interpreted as explicitly disclosing all such permutations. For example, a system described as having three optional features can be embodied in seven ways: having only one of the three possible features, having any two of the three possible features, or having three of the three possible features.

[0062] Many elements described in the disclosed embodiments can be implemented as modules. A module is defined herein as an element that performs the defined function and has defined interfaces to other elements. Modules described in this disclosure can be implemented in the form of hardware, software combined with hardware, firmware, wet hardware (i.e., hardware with biological elements), or combinations thereof (the foregoing may be behaviorally equivalent). For example, a module can be implemented as software routines written in a computer language configured to be executed by a hardware machine (such as C, C++, Fortran, Java, Basic, Matlab, etc.) or a modeling / simulation program (such as Simulink, Stateflow, GNU Octave, or LabVIEW MathScript). Modules can be implemented using physical hardware incorporating discrete or programmable analog, digital, and / or quantum hardware. Examples of programmable hardware include: computers, microcontrollers, microprocessors, application-specific integrated circuits (ASICs); field-programmable gate arrays (FPGAs); and complex programmable logic devices (CPLDs). Computers, microcontrollers, and microprocessors are programmed using languages ​​such as assembly, C, C++, etc. FPGAs, ASICs, and CPLDs are frequently programmed using hardware description languages ​​(HDLs), such as VHSIC Hardware Description Language (VHDL) or Verilog. These languages ​​configure connections between relatively few internal hardware modules on a programmable device. The aforementioned techniques are often used in combination to achieve the desired functional modules.

[0063] Figure 1A An example of a mobile communication network 100 in which embodiments of the present disclosure may be implemented is shown. The mobile communication network 100 may, for example, be a Public Land Mobile Network (PLMN) operated by a network operator. Figure 1A As shown, the mobile communication network 100 includes a core network (CN) 102, a radio access network (RAN) 104, and a radio device 106.

[0064] CN 102 can provide the wireless device 106 with an interface to one or more data networks (DNs), such as a public DN (e.g., the Internet), a private DN, and / or an operator's internal DN. As part of the interface functionality, CN 102 can establish an end-to-end connection between the wireless device 106 and the one or more DNs, authenticate the wireless device 106, and provide billing functionality.

[0065] RAN 104 can connect CN 102 to radio device 106 via radio communication over an air interface. As part of the radio communication, RAN 104 can provide scheduling, radio resource management, and retransmission protocols. The communication direction from RAN 104 to radio device 106 via the air interface is referred to as the downlink, while the communication direction from radio device 106 to RAN 104 via the air interface is referred to as the uplink. Downlink transmissions can be separated from uplink transmissions using Frequency Division Duplex (FDD), Time Division Duplex (TDD), and / or some combination of these two duplexing technologies.

[0066] The term "wireless device" may be used throughout this disclosure to mean and cover any mobile or fixed (non-mobile) device that requires or has wireless communication available to it. For example, a wireless device may be a telephone, smartphone, tablet, computer, laptop computer, sensor, instrument, wearable device, Internet of Things (IoT) device, roadside unit (RSU) of a vehicle, relay node, automobile, and / or any combination thereof. The term "wireless device" also encompasses other terms including user equipment (UE), user terminal (UT), access terminal (AT), mobile station, mobile phone, wireless transceiver unit (WTRU), and / or wireless communication device.

[0067] RAN 104 may include one or more base stations (not shown). The term "base station" may be used throughout this disclosure to mean and encompass: Node B (associated with UMTS and / or 3G standards); Evolved Node B (eNB, associated with E-UTRA and / or 4G standards); Remote Radio Header (RRH); Baseband processing unit coupled to one or more RRHs; Repeater or Relay node for extending the coverage area of ​​a donor node; Next Generation Evolved Node B (ng-eNB); Generation Node B (gNB, associated with NR and / or 5G standards); Access Point (AP, associated with, for example, WiFi or any other suitable wireless communication standard); and / or any combination thereof. A base station may include at least one gNB Central Unit (gNB-CU) and at least one gNB Distributed Unit (gNB-DU).

[0068] The base stations included in RAN 104 may include one or more sets of antennas for communicating with the wireless device 106 via an air interface. For example, one or more base stations may include three sets of antennas to control three cells (or sectors) respectively. The size of a cell may be determined based on the range within which a receiver (e.g., a base station receiver) can successfully receive transmissions from a transmitter (e.g., a wireless device transmitter) operating in that cell. The cells of the base stations may together provide radio coverage over a wide geographical area to the wireless device 106 to support wireless device mobility.

[0069] Besides three-sector sites, other implementations of the base stations are also possible. For example, one or more base stations in RAN 104 can be implemented as sectorized sites with more or fewer than three sectors. One or more base stations in RAN 104 can be implemented as access points, as baseband processing units coupled to several remote radio heads (RRHs), and / or as repeaters or relay nodes for extending the coverage area of ​​the donor node. The baseband processing unit coupled to the RRH can be part of a centralized RAN architecture or a cloud RAN architecture, where the baseband processing unit can be centralized in a pool of baseband processing units or virtualized. Repeater nodes can amplify and replay radio signals received from the donor node. Relay nodes can perform the same / similar functions as repeater nodes, but can decode the radio signals received from the donor node to remove noise before amplifying and replaying the radio signals.

[0070] RAN 104 can be adopted as a homogeneous network of macrocell base stations with similar antenna patterns and similar high-level transmit power. RAN 104 can also be adopted as a heterogeneous network. In a heterogeneous network, small cell base stations can be used to provide small coverage areas, such as coverage areas overlapping with the relatively large coverage areas provided by macrocell base stations. Small coverage areas can be provided in areas with high data traffic (or so-called "hot spots") or in areas with weak macrocell coverage. Examples of small cell base stations, in descending order of coverage area, include: microcell base stations, picocell base stations, and femtocell base stations or home base stations.

[0071] The Third Generation Partnership Project (3GPP) was established in 1998 to facilitate collaboration with... Figure 1A The mobile communication network 100 in this disclosure provides globally standardized specifications for similar mobile communication networks. To date, 3GPP has defined specifications for three generations of mobile networks: the third-generation (3G) network known as Universal Mobile Telecommunications System (UMTS), the fourth-generation (4G) network known as Long Term Evolution (LTE), and the fifth-generation (5G) network known as 5G System (5GS). The embodiments of this disclosure are described with reference to the RAN of the 3GPP 5G network, known as Next Generation RAN (NG-RAN). These embodiments can be applied to the RAN of other mobile communication networks, such as... Figure 1A RAN 104, RANs of early 3G and 4G networks, and those RANs of future networks that have not yet been specified (e.g., 3GPP 6G networks). NG-RAN implements 5G radio access technology known as New Radio (NR) and can be configured to implement 4G radio access technology or other radio access technologies, including non-3GPP radio access technologies.

[0072] Figure 1BAnother exemplary mobile communication network 150 in which embodiments of the present disclosure can be implemented is shown. The mobile communication network 150 may be, for example, a PLMN operated by a network operator. Figure 1B As shown, the mobile communication network 150 includes a 5G core network (5G-CN) 152, an NG-RAN 154, and UEs 156A and 156B (collectively referred to as UE 156). This can be compared with... Figure 1A These components are implemented and operated in the same or similar ways as the corresponding components described.

[0073] 5G-CN 152 provides UE 156 with an interface to one or more DNs, such as public DNs (e.g., the Internet), private DNs, and / or operator-internal DNs. As part of the interface functionality, 5G-CN 152 can establish end-to-end connections between UE 156 and these one or more DNs, authenticate UE 156, and provide charging functions. Compared to the CNs in 3GPP 4G networks, the foundation of 5G-CN 152 can be a service-based architecture. This means that the architecture of the nodes constituting 5G-CN 152 can be defined as network functions that provide services to other network functions via the interface. The network functions of 5G-CN 152 can be implemented in several ways, including as network elements on dedicated or shared hardware, as software instances running on dedicated or shared hardware, or as virtualized functions instantiated on a platform (e.g., a cloud-based platform).

[0074] like Figure 1B As shown, 5G-CN 152 includes Access and Mobility Management Function (AMF) 158A and User Plane Function (UPF) 158B. For ease of explanation, in Figure 1B These are shown as a single component, AMF / UPF 158. UPF 158B can act as a gateway between NG-RAN 154 and the one or more DNs. Functions that UPF 158B can perform include: packet routing and forwarding, packet inspection and user plane policy rule enforcement, service usage reporting, uplink classification supporting the routing of service flows to the one or more DNs, user plane Quality of Service (QoS) processing (e.g., packet filtering, gating, uplink / downlink rate enforcement, and uplink service authentication), downlink packet buffering, and downlink data notification triggering. UPF 158B can act as an anchor point for intra / inter-Radio Access Technology (RAT) mobility, an external Protocol (or Packet) Data Unit (PDU) session point interconnected with the one or more DNs, and / or a pivot point supporting multihomed PDU sessions. UE 156 can be configured to receive services via a PDU session, which is a logical connection between the UE and the DN.

[0075] The AMF 158A can perform functions such as: Non-Access Layer (NAS) signaling termination, NAS signaling security, Access Layer (AS) security control, inter-CN node signaling for mobility between 3GPP access networks, idle mode UE reachability (e.g., control and execution of paging retransmission), registration area management, intra-system and inter-system mobility support, access authentication, access authorization including roaming rights verification, mobility management control (subscription and policies), network slicing support, and / or Session Management Function (SMF) selection. NAS can refer to functions operating between the CN and the UE, and AS can refer to functions operating between the UE and the RAN.

[0076] 5G-CN 152 may include, for clarity, not listed here. Figure 1B One or more additional network functions are shown in the diagram. For example, 5G-CN 152 may include one or more of the following: Session Management Function (SMF), NR Repository Function (NRF), Policy Control Function (PCF), Network Openness Function (NEF), Unified Data Management (UDM), Application Function (AF), and / or Authentication Server Function (AUSF).

[0077] NG-RAN 154 can connect 5G-CN 152 to UE 156 via radio communication over an air interface. NG-RAN 154 may include: one or more gNBs, such as gNB 160A and gNB 160B (collectively referred to as gNB 160); and / or one or more ng-eNBs, such as ng-eNB 162A and ng-eNB 162B (collectively referred to as ng-eNB 162). gNB 160 and ng-eNB 162 may be more generally referred to as base stations. gNB 160 and ng-eNB 162 may include one or more sets of antennas for communicating with UE 156 over the air interface. For example, one or more of gNB 160 and / or one or more of ng-eNB 162 may include three sets of antennas to control three cells (or sectors) respectively. The gNB 160 and ng-eNB 162 cells can work together to provide UE 156 with radio coverage over a wide geographical area to support UE mobility.

[0078] like Figure 1B As shown, gNB 160 and / or ng-eNB 162 can connect to 5G-CN 152 via the NG interface and to other base stations via the Xn interface. The NG and Xn interfaces can be established using a direct physical connection and / or an indirect connection via a potential transport network (such as an Internet Protocol (IP) transport network). gNB 160 and / or ng-eNB 162 can connect to UE 156 via the Uu interface. For example, as... Figure 1B As shown, the gNB 160A can connect to the UE 156A via the Uu interface. The NG, Xn, and Uu interfaces are associated with a protocol stack. The protocol stack associated with the interface can be... Figure 1B The network elements in the system are used to exchange data and signaling messages, and can include two planes: a user plane and a control plane. The user plane can handle data that is of interest to the user. The control plane can handle signaling messages that are of interest to the network elements.

[0079] The gNB 160 and / or ng-eNB 162 can connect to one or more AMF / UPF functions of the 5G-CN 152, such as AMF / UPF 158, via one or more NG interfaces. For example, the gNB 160A can connect to the UPF 158B of the AMF / UPF 158 via an NG user plane (NG-U) interface. The NG-U interface can provide user plane PDU delivery (e.g., non-guaranteed delivery) between the gNB 160A and the UPF 158B. The gNB 160A can connect to the AMF158A via an NG control plane (NG-C) interface. The NG-C interface can provide, for example, NG interface management, UE context management, UE mobility management, NAS message delivery, paging, PDU session management, and configuration delivery and / or warning message transmission.

[0080] The gNB 160 can provide NR user plane and control plane protocol termination to UE 156 via the Uu interface. For example, the gNB 160A can provide NR user plane and control plane protocol termination to UE 156A via the Uu interface associated with the first protocol stack. The ng-eNB 162 can provide Evolved UMTS Terrestrial Radio Access (E-UTRA) user plane and control plane protocol termination to UE 156 via the Uu interface, where E-UTRA refers to 3GPP 4G radio access technology. For example, the ng-eNB 162B can provide E-UTRA user plane and control plane protocol termination to UE 156B via the Uu interface associated with the second protocol stack.

[0081] 5G-CN 152 is described as being configured to handle NR and 4G radio access. Those skilled in the art will understand that NR can potentially connect to the 4G core network in a mode known as “non-standalone operation.” In non-standalone operation, the 4G core network is used to provide (or at least support) control plane functions (e.g., initial access, mobility, and paging). Although Figure 1B The diagram shows only one AMF / UPF 158, but a gNB or ng-eNB can connect to multiple AMF / UPF nodes to provide redundancy and / or load sharing across those multiple AMF / UPF nodes.

[0082] As discussed, Figure 1B The interfaces between network elements (e.g., Uu, Xn, and NG interfaces) can be associated with the protocol stack used by the network elements to exchange data and signaling messages. The protocol stack can include two planes: a user plane and a control plane. The user plane handles data of interest to the user, while the control plane handles signaling messages of interest to the network elements.

[0083] Figure 2A and Figure 2B Examples of NR user plane and NR control plane protocol stacks for the Uu interface located between UE 210 and gNB 220 are shown respectively. Figure 2A and Figure 2B The protocol stack shown can be used with, for example, Figure 1B The protocol stacks of the Uu interface between UE156A and gNB 160A shown are the same or similar.

[0084] Figure 2A The diagram illustrates a five-layer NR user plane protocol stack implemented in UE 210 and gNB 220. At the bottom of the stack, the Physical Layer (PHY) 211 and 221 provide transport services to the higher layers and can correspond to Layer 1 of the Open Systems Interconnection (OSI) model. The next four protocols above PHY 211 and 221 include the Medium Access Control (MAC) layer 212 and 222, the Radio Link Control (RLC) layer 213 and 223, the Packet Data Convergence Protocol (PDCP) layer 214 and 224, and the Service Data Application Protocol (SDAP) layer 215 and 225. These four protocols together can constitute Layer 2 of the OSI model or the Data Link Layer.

[0085] Figure 3 This illustrates an example of services provided between protocol layers in the NR user plane protocol stack. From Figure 2A and Figure 3Starting from the top, SDAPs 215 and 225 can perform QoS flow processing. UE 210 can receive services through a PDU session, which can be a logical connection between UE 210 and the DN. The PDU session can have one or more QoS flows. The CN's UPF (e.g., UPF 158B) can map IP packets to these one or more QoS flows of the PDU session based on QoS requirements (e.g., in terms of latency, data rate, and / or error rate). SDAPs 215 and 225 can perform mapping / demapping between these one or more QoS flows and one or more data radio bearers. The mapping / demapping between QoS flows and data radio bearers can be determined by SDAP 225 at gNB 220. SDAP 215 at UE 210 can learn the mapping between QoS flows and data radio bearers through reflected mapping or control signaling received from gNB 220. For reflective mapping, the SDAP 225 at gNB 220 can mark downlink packets with a QoS flow indicator (QFI), which can be observed by the SDAP 215 at UE 210 to determine the mapping / demapping between QoS flows and data radio bearers.

[0086] PDCP 214 and 224 can perform header compression / decompression to reduce the amount of data that needs to be transmitted over the air interface, can perform encryption / decryption to prevent unauthorized decoding of data transmitted over the air interface, and can perform integrity protection to ensure that control messages originate from their intended source. PDCP 214 and 224 can perform retransmission of undelivered packets, reordering and repackaging of packets, and removal of duplicate packets received due to, for example, intra-gNB handover. PDCP 214 and 224 can perform packet duplication to increase the likelihood of packet reception and remove any duplicate packets at the receiver. Packet duplication can be suitable for services requiring high reliability.

[0087] although Figure 3 Although not shown, PDCP 214 and 224 can perform mapping / demapping between split radio bearers and RLC channels in a dual connectivity scenario. Dual connectivity is a technique that allows a UE to connect to two cells or more generally to two cell groups: a primary cell group (MCG) and a secondary cell group (SCG). Split bearers are those that occur when a single radio bearer (such as one of the radio bearers provided by PDCP 214 and 224 as a service to SDAP 215 and 225) is handled by a cell group in dual connectivity. PDCP 214 and 224 can map / demapping split radio bearers between RLC channels belonging to a cell group.

[0088] RLCs 213 and 223 can respectively perform segmentation, retransmission via Automatic Repeat Request (ARQ), and removal of duplicate data units received from MACs 212 and 222. RLCs 213 and 223 can support three transmission modes: Transparent Mode (TM); Unacknowledged Mode (UM); and Acknowledged Mode (AM). Based on the transmission mode the RLC is operating in, the RLC can perform one or more of the aforementioned functions. RLC configuration can be based on each logical channel, independent of parameter sets and / or Transmission Time Interval (TTI) duration. Figure 3 As shown, RLC 213 and 223 can provide RLC channels respectively as services to PDCP 214 and 224.

[0089] MACs 212 and 222 can perform multiplexing / demultiplexing of logical channels and / or mapping between logical channels and transport channels. Multiplexing / demultiplexing may include multiplexing data units belonging to one or more logical channels into / from a transport module (TB) delivered to / from PHYs 211 and 221. MAC 222 can be configured to perform scheduling, scheduling information reporting, and priority processing between UEs via dynamic scheduling. Scheduling can be performed on downlink and uplink in gNB 220 (at MAC 222). MACs 212 and 222 can be configured to perform error correction via Hybrid Automatic Repeat Request (HARQ) (e.g., one HARQ entity per carrier in the case of carrier aggregation (CA), priority processing between logical channels of UE 210 via logical channel priority ordering, and / or padding. MACs 212 and 222 may support one or more parameter sets and / or transmission timing. In the example, mapping constraints in logical channel priority ordering can control which parameter set and / or transmission timing the logical channel can use. For example... Figure 3 As shown, MACs 212 and 222 can provide logical channels as services to RLCs 213 and 223.

[0090] PHYs 211 and 221 can perform transport-to-physical channel mapping and digital and analog signal processing functions for transmitting and receiving information over the air interface. These digital and analog signal processing functions may include, for example, encoding / decoding and modulation / demodulation. PHYs 211 and 221 can perform multi-antenna mapping. For example... Figure 3 As shown, PHYs 211 and 221 can provide one or more transport channels as services to MACs 212 and 222.

[0091] Figure 4A An exemplary downlink data flow through the NR user plane protocol stack is shown. Figure 4AThe diagram illustrates the downlink data flow through the NR user plane protocol stack to generate three IP packets (n, n+1, and m) of two TB at the gNB 220. The uplink data flow through the NR user plane protocol stack can be compared with... Figure 4A The downlink data flow described in the text is similar.

[0092] Figure 4A The downlink data flow begins when SDAP 225 receives three IP packets from one or more QoS flows and maps those three packets to a radio bearer. Figure 4A In SDAP 225, IP packets n and n+1 are mapped to the first radio bearer 402, and IP packet m is mapped to the second radio bearer 404. The SDAP header (in...) Figure 4A Data units marked with "H" are added to IP packets. Data units originating from / going to a higher protocol layer are called lower protocol layer Service Data Units (SDUs), and data units originating from / going to a lower protocol layer are called higher protocol layer Protocol Data Units (PDUs). Figure 4A As shown, the data unit from SDAP 225 is the SDU of the lower protocol layer PDCP 224 and the PDU of SDAP 225.

[0093] Figure 4A The remaining protocol layers can perform their associated functions (e.g., regarding...). Figure 3 This involves adding the corresponding headers and forwarding their output to the next lower layer. For example, PDCP 224 can perform IP header compression and encryption, and forward its output to RLC 223. RLC 223 can optionally perform fragmentation (e.g., as...). Figure 4A (As shown in the image regarding IP packet m) and forwards its output to MAC 222. MAC 222 can multiplex many RLC PDUs and can attach MAC subheaders to RLC PDUs to form transport blocks. In NR, MAC subheaders can be distributed throughout MAC PDUs, such as... Figure 4A As shown in the diagram. In LTE, the MAC sub-header can be located entirely at the beginning of the MAC PDU. The NR MAC PDU structure can reduce processing time and associated latency because the MAC PDU sub-header can be computed before the complete MAC PDU is assembled.

[0094] Figure 4BAn exemplary format of the MAC subheader in a MAC PDU is shown. The MAC subheader includes: an SDU length field indicating the length (e.g., in bytes) of the MAC SDU to which the MAC subheader corresponds; a Logical Channel Identifier (LCID) field identifying the logical channel from which the MAC SDU originates to assist in the demultiplexing process; a flag (F) indicating the size of the SDU length field; and a reserved bit (R) field for future use.

[0095] Figure 4B The diagram further illustrates a MAC control element (CE) inserted into the MAC PDU by a MAC (such as MAC 223 or MAC 222). For example, Figure 4B This shows two MAC CEs inserted into the MAC PDU. These can be used at the beginning of downlink transmissions within the MAC PDU (e.g., ...). Figure 4B (As shown in the diagram) and a MAC CE is inserted at the end of the uplink transmission of the MAC PDU. The MAC CE can be used for in-band control signaling. Exemplary MAC CEs include: scheduling-related MAC CEs, such as buffer status reports and power headroom reports; activation / deactivation MAC CEs, such as those for PDCP repeated detection, channel state information (CSI) reports, sounding reference signal (SRS) transmission, and activation / deactivation of previously configured components; discontinuous reception (DRX)-related MAC CEs; timing advance MAC CEs; and random access-related MAC CEs. A MAC subheader with a format similar to that described with respect to the MAC SDU may precede the MAC CE, and the MAC CE may be identified by a reserved value in the LCID field indicating the type of control information included in the MAC CE.

[0096] Before describing the NR control plane protocol stack, we will first describe the mapping between logical channels, transport channels, and physical channels, as well as channel types. One or more of these channels can be used to perform functions associated with the NR control plane protocol stack, which will be described later below.

[0097] Figure 5A and Figure 5BThe mappings between logical channels, transport channels, and physical channels are shown for both downlink and uplink. Information is transmitted through channels between the RLC, MAC, and PHY of the NR protocol stack. Logical channels can be used between the RLC and MAC and can be classified as control channels carrying control and configuration information in the NR control plane, or as service channels carrying data in the NR user plane. Logical channels can be classified as dedicated logical channels for a specific UE, or as common logical channels that can be used by more than one UE. Logical channels can also be defined by the type of information they carry. The set of logical channels defined by NR includes, for example:

[0098] - Paging Control Channel (PCCH), which carries paging messages for paging UEs whose location is unknown to the network at the cell level;

[0099] - Broadcast Control Channel (BCCH), which carries system information messages in the form of a Master Information Block (MIB) and several System Information Blocks (SIB), wherein the system information messages can be used by the UE to obtain information about how the cell is configured and how to operate within the cell;

[0100] - Common Control Channel (CCCH), which is used to carry control messages and random access;

[0101] - Dedicated Control Channel (DCCH), used to carry control messages to a specific UE / carry control messages from a specific UE to configure that UE; and

[0102] - Dedicated Service Channel (DTCH), which is used to carry user data to a specific UE or carry user data from a specific UE.

[0103] Transport channels are used between the MAC layer and the PHY layer, and can be defined by how the information they carry is transmitted over the air interface. The set of transport channels defined by NR includes, for example:

[0104] - Paging Channel (PCH), which is used to carry paging messages originating from PCCH;

[0105] - Broadcast channel (BCH), which is used to carry MIBs from the BCCH;

[0106] - Downlink Shared Channel (DL-SCH), which is used to carry downlink data and signaling messages, including SIBs from BCCH;

[0107] - Uplink Shared Channel (UL-SCH), used to carry uplink data and signaling messages; and

[0108] - Random Access Channel (RACH), which is used to allow a UE to access the network without any prior scheduling.

[0109] The PHY can use physical channels to transfer information between processing levels of the PHY. A physical channel can be a set of associated time-frequency resources used to carry information from one or more transport channels. The PHY can generate control information to support lower-level PHY operations and provide this control information to lower levels of the PHY via physical control channels (referred to as L1 / L2 control channels). The set of physical channels and physical control channels defined by NR includes, for example:

[0110] - Physical Broadcast Channel (PBCH), which is used to carry MIBs from the BCH;

[0111] - The Physical Downlink Shared Channel (PDSCH) is used to carry downlink data and signaling messages from the DL-SCH and paging messages from the PCH;

[0112] - The Physical Downlink Control Channel (PDCCH) carries downlink control information (DCI), which may include downlink scheduling commands, uplink scheduling permissions, and uplink power control commands;

[0113] - The Physical Uplink Shared Channel (PUSCH) is used to carry uplink data and signaling messages from the UL-SCH, and in some cases, uplink control information (UCI) as described below.

[0114] - The Physical Uplink Control Channel (PUCCH), which carries the UCI, including HARQ acknowledgments, Channel Quality Indicator (CQI), Precoding Matrix Indicator (PMI), Rank Indicator (RI), and Scheduling Request (SR); and

[0115] - Physical Random Access Channel (PRACH), which is used for random access.

[0116] Similar to the physical control channel, the physical layer generates physical signals to support low-level physical layer operations. For example... Figure 5A and Figure 5B As shown, the physical layer signals defined by NR include: Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Channel State Information Reference Signal (CSI-RS), Demodulation Reference Signal (DMRS), Sounding Reference Signal (SRS), and Phase Tracking Reference Signal (PT-RS). These physical layer signals will be described in more detail below.

[0117] Figure 2B An exemplary NR control plane protocol stack is shown. Figure 2BAs shown, the NR control plane protocol stack can use the same / similar first four protocol layers as the exemplary NR user plane protocol stack. These four protocol layers include PHY 211 and 221, MAC 212 and 222, RLC 213 and 223, and PDCP 214 and 224. Instead of having SDAP 215 and 225 at the top of the stack as in the NR user plane protocol stack, the NR control plane protocol stack has Radio Resource Control (RRC) 216 and 226 and NAS protocols 217 and 237 at the top of the NR control plane protocol stack.

[0118] NAS protocols 217 and 237 can provide control plane functions between UE 210 and AMF 230 (e.g., AMF 158A) or more generally between UE 210 and CN. NAS protocols 217 and 237 can provide control plane functions between UE 210 and AMF 230 via signaling messages known as NAS messages. There is no direct path through which NAS messages can be transmitted between UE 210 and AMF 230. NAS messages can be transmitted using the AS of the Uu and NG interfaces. NAS protocols 217 and 237 can provide control plane functions such as authentication, security, connection setup, mobility management, and session management.

[0119] RRC 216 and 226 can provide control plane functionality between UE 210 and gNB 220, or more generally between UE 210 and RAN. RRC 216 and 226 can provide control plane functionality between UE 210 and gNB 220 via signaling messages known as RRC messages. RRC messages can be transmitted between UE 210 and RAN using signaling radio bearers and the same / similar PDCP, RLC, MAC, and PHY protocol layers. MAC can multiplex control plane and user plane data into the same transport block (TB). RRC 216 and 226 can provide control plane functions such as: broadcasting system information related to AS and NAS; paging initiated by CN or RAN; establishment, maintenance, and release of RRC connections between UE 210 and RAN; security functions including key management; establishment, configuration, maintenance, and release of signaling radio bearers and data radio bearers; mobility functions; QoS management functions; UE measurement reporting and control of such reporting; detection and recovery of radio link failures (RLFs); and / or NAS messaging. As part of establishing an RRC connection, RRC 216 and 226 can establish an RRC context, which may involve configuring parameters for communication between UE 210 and RAN.

[0120] Figure 6 This is an example diagram illustrating the RRC state transition of the UE. The UE can interact with... Figure 1A The wireless device 106 depicted in the text Figure 2A and Figure 2B The UE 210 depicted herein is identical or similar to any other wireless device described in this disclosure. Figure 6 As shown, the UE can be in at least one of three RRC states: RRC connected 602 (e.g., RRC_CONNECTED), RRC idle 604 (e.g., RRC_IDLE), and RRC inactive 606 (e.g., RRC_INACTIVE).

[0121] In RRC connection 602, the UE has an established RRC context and may have at least one RRC connection with a base station. The base station may be similar to one of the following: Figure 1A The one or more base stations included in RAN 104 as depicted herein; Figure 1B One of gNB 160 or ng-eNB 162 described herein; Figure 2A and Figure 2B The gNB220 depicted in this disclosure; or any other base station described herein. A base station connected to a UE may have an RRC context for that UE. The RRC context, referred to as the UE context, may include parameters for communication between the UE and the base station. These parameters may include, for example: one or more AS contexts; one or more radio link configuration parameters; bearer configuration information (e.g., relating to data radio bearers, signaling radio bearers, logical channels, QoS flows, and / or PDU sessions); security information; and / or PHY, MAC, RLC, PDCP, and / or SDAP layer configuration information. When in RRC connection 602, the UE's mobility may be managed by the RAN (e.g., RAN 104 or NG-RAN 154). The UE may measure signal levels (e.g., reference signal levels) from the serving cell and neighboring cells and report these measurements to the base station currently serving the UE. The UE's serving base station may request a cell transfer to one of the neighboring base stations based on the reported measurements. The RRC state can be changed from RRC connection 602 to RRC idle 604 through connection release procedure 608, or to RRC inactive 606 through connection deactivation procedure 610.

[0122] In RRC Idle 604, an RRC context may not have been established for the UE. In RRC Idle 604, the UE may not have an RRC connection with the base station. When in RRC Idle 604, the UE may be in a sleep state most of the time (e.g., to conserve battery power). The UE may periodically wake up (e.g., once in each discontinuous reception cycle) to monitor paging messages from the RAN. The UE's mobility can be managed by the UE through a procedure called cell reselection. The RRC state can be transitioned from RRC Idle 604 to RRC Connection 602 through Connection Establishment Procedure 612, which may involve a random access procedure, as discussed in more detail below.

[0123] In RRC inactivity 606, the previously established RRC context is maintained in both the UE and the base station. This allows for a faster transition to RRC connection 602 with reduced signaling overhead compared to the transition from RRC idle 604 to RRC connected 602. While in RRC inactivity 606, the UE can be in a sleep state, and the UE's mobility can be managed by the UE via cell reselection. The RRC state can transition from RRC inactivity 606 to RRC connection 602 via connection resumption procedure 614, or to RRC idle 604 via connection release procedure 616, which can be the same as or similar to connection release procedure 608.

[0124] RRC states can be associated with mobility management mechanisms. In RRC Idle 604 and RRC Inactive 606, mobility is managed by the UE through cell reselection. The purpose of mobility management in RRC Idle 604 and RRC Inactive 606 is to allow the network to notify the UE of events via paging messages without having to broadcast paging messages across the entire mobile network. The mobility management mechanisms used in RRC Idle 604 and RRC Inactive 606 allow the network to track the UE at the cell group level, so that paging messages can be broadcast on the cells in the cell group where the UE is currently camped, rather than across the entire mobile network. Mobility management mechanisms for RRC Idle 604 and RRC Inactive 606 track the UE at the cell group level. These mobility management mechanisms can do this using groupings of different granularities. For example, there can be three levels of cell grouping granularity: a single cell; cells within a RAN area identified by a RAN Area Identifier (RAI); and cells within a group of RAN areas called tracking areas and identified by a Tracking Area Identifier (TAI).

[0125] A tracking area can be used to track the UE at the CN level. The CN (e.g., CN 102 or 5G-CN 152) can provide the UE with a list of TAIs associated with the UE's registration area. If the UE moves to a cell associated with a TAI not included in the list of TAIs associated with the UE's registration area via cell reselection, the UE can perform a registration update with the CN to allow the CN to update the UE's location and provide the UE with a new UE registration area.

[0126] RAN areas can be used to track UEs at the RAN level. For a UE in an RRC inactive 606 state, a RAN notification area can be assigned to that UE. A RAN notification area can include one or more cell identities, a list of RAIs, or a list of TAIs. In the example, a base station can belong to one or more RAN notification areas. In the example, a cell can belong to one or more RAN notification areas. If a UE moves via cell reselection to a cell not included in its assigned RAN notification area, the UE can perform a notification area update to update its RAN notification area.

[0127] The base station that stores the RRC context for the UE, or the UE's last serving base station, can be referred to as the anchor base station. The anchor base station may maintain the RRC context for the UE at least during the period when the UE remains in the anchor base station's RAN notification area and / or during the period when the UE remains in RRC inactivity 606.

[0128] gNB, such as Figure 1B The gNB 160 can be divided into two parts: a central unit (gNB-CU) and one or more distributed units (gNB-DU). The gNB-CU can be coupled to one or more gNB-DUs using an F1 interface. The gNB-CU may include RRC, PDCP, and SDAP. The gNB-DU may include RLC, MAC, and PHY.

[0129] In NR, physical signals and physical channels (about Figure 5A and Figure 5BThe concepts discussed can be mapped onto Orthogonal Frequency Division Multiplexing (OFDM) symbols. OFDM is a multi-carrier communication scheme that transmits data via F orthogonal subcarriers (or tones). Before transmission, the data can be mapped to a series of complex symbols called source symbols (e.g., M-QAM or M-PSK symbols) and divided into F parallel symbol streams. These F parallel symbol streams can be treated as if they were in the frequency domain and used as input to an Inverse Fast Fourier Transform (IFFT) block that transforms them into the time domain. The IFFT block takes F source symbols at a time (one source symbol from each of the F parallel symbol streams) and uses each source symbol to modulate the amplitude and phase of one of the F sinusoidal basis functions corresponding to the F orthogonal subcarriers. The output of the IFFT block can be F time-domain samples representing the sum of the F orthogonal subcarriers. These F time-domain samples can form a single OFDM symbol. After some processing (e.g., addition of a cyclic prefix) and upsampling, the OFDM symbols provided by the IFFT block can be transmitted over the air interface at the carrier frequency. The F parallel symbol streams can be mixed using an FFT block before being processed by the IFFT block. This operation produces OFDM symbols precoded with Discrete Fourier Transform (DFT) and can be used by the UE in the uplink to reduce the peak-to-average power ratio (PAPR). The inverse processing of the OFDM symbols at the receiver can be performed using the FFT block to recover the data mapped to the source symbols.

[0130] Figure 7 An exemplary configuration of NR frames in which OFDM symbols are grouped is shown. NR frames can be identified by a System Frame Number (SFN). An SFN can repeat for a period of 1024 frames. As shown, the duration of an NR frame can be 10 milliseconds (ms) and can include 10 subframes with a duration of 1 ms. Subframes can be divided into time slots, which include, for example, 14 OFDM symbols per time slot.

[0131] The duration of a time slot can depend on the parameter set of the OFDM symbols used for that time slot. NR supports flexible parameter sets to accommodate different cell deployments (e.g., cells with carrier frequencies below 1 GHz, up to cells with carrier frequencies in the mmWave range). Parameter sets can be defined in terms of subcarrier spacing and cyclic prefix duration. For parameter sets in NR, the subcarrier spacing can be scaled up by two powers from a baseline subcarrier spacing of 15 kHz, and the cyclic prefix duration can be scaled down by two powers from a baseline cyclic prefix duration of 4.7 μs. For example, NR defines parameter sets with the following combinations of subcarrier spacing / cyclic prefix duration: 15 kHz / 4.7 μs; 30 kHz / 2.3 μs; 60 kHz / 1.2 μs; 120 kHz / 0.59 μs; and 240 kHz / 0.29 μs.

[0132] A time slot can have a fixed number of OFDM symbols (e.g., 14 OFDM symbols). A parameter set with a higher subcarrier spacing has a shorter time slot duration and correspondingly more time slots per subframe. Figure 7 This illustrates the transmission structure of the time slot duration and per subframe time slot related to the parameter set (for ease of explanation). Figure 7 (The parameter set with a subcarrier spacing of 240 kHz is not shown in the diagram). Subframes in NR can be used as a time reference independent of the parameter set, while time slots can be used as units for scheduling uplink and downlink transmissions. To support low latency, scheduling in NR can be separated from the time slot duration and begin at any OFDM symbol, continuing to transmit as many symbols as needed. These partial time slot transmissions can be referred to as micro-time slot or sub-time slot transmissions.

[0133] Figure 8 An exemplary configuration of a time slot in the time and frequency domains of an NR carrier is shown. This time slot includes a resource element (RE) and a resource block (RB). An RE is the smallest physical resource in NR. An RE spans one OFDM symbol in the time domain via a subcarrier in the frequency domain, such as... Figure 8 As shown. RB spans twelve consecutive REs in the frequency domain, as... Figure 8 As shown. The NR carrier can be limited to a width of 275 RB or 275 × 12 = 3300 subcarriers. If this limitation is used, the NR carrier can be limited to 50, 100, 200, and 400 MHz for subcarrier spacing of 15, 30, 60, and 120 kHz, respectively, where the 400 MHz bandwidth can be set based on the limitation of 400 MHz bandwidth per carrier.

[0134] Figure 8This illustrates a single set of parameters used across the entire bandwidth of an NR carrier. In other exemplary configurations, multiple parameter sets can be supported on the same carrier.

[0135] NR can support wide carrier bandwidths (e.g., up to 400MHz for a subcarrier spacing of 120kHz). Not all UEs can receive the full carrier bandwidth (e.g., due to hardware limitations). Moreover, receiving the full carrier bandwidth can be prohibitively expensive in terms of UE power consumption. In the example, to reduce power consumption and / or for other purposes, the UE can adjust the size of its receive bandwidth based on the amount of traffic it plans to receive. This is called bandwidth adaptation.

[0136] The NR defines a Bandwidth Component (BWP) to support UEs that cannot receive the full carrier bandwidth and to support bandwidth adaptation. In the example, a BWP can be defined by a subset of consecutive Relays (RBs) on a carrier. A UE can be configured (e.g., via the RRC layer) to have one or more downlink BWPs and one or more uplink BWPs per serving cell (e.g., up to four downlink BWPs and up to four uplink BWPs per serving cell). At a given time, one or more of the configured BWPs for the serving cell can be active. These one or more BWPs can be referred to as the active BWPs of the serving cell. When the serving cell is configured with a secondary uplink carrier, the serving cell can have one or more first active BWPs on the uplink carrier and one or more second active BWPs on the secondary uplink carrier.

[0137] For unpaired spectrum, if the downlink BWP index of the downlink BWP is the same as the uplink BWP index of the uplink BWP, then the downlink BWP from the set of configured downlink BWPs can link with the uplink BWP from the set of configured uplink BWPs. For unpaired spectrum, the UE can expect the center frequency of the downlink BWP to be the same as the center frequency of the uplink BWP.

[0138] For a set of configured downlink BWPs on the primary cell (PCell), the base station can configure a UE with one or more control resource sets (CORESETs) for at least one search space. A search space is a set of locations in the time and frequency domains where the UE can locate control information. The search space can be a UE-specific search space or a common search space (potentially usable by multiple UEs). For example, the base station can configure a common search space for the UE on the PCell or primary / secondary cell (PSCell) within active downlink BWPs.

[0139] For an uplink BWP in a set of configured uplink BWPs, the BS can configure one or more resource sets for the UE for one or more PUCCH transmissions. The UE can receive downlink receptions (e.g., PDCCH or PDSCH) in the downlink BWP based on a configured set of parameters (e.g., subcarrier spacing and cyclic prefix duration) for the downlink BWP. The UE can transmit uplink transmissions (e.g., PUCCH or PUSCH) in the uplink BWP based on a configured set of parameters (e.g., subcarrier spacing and cyclic prefix length of the uplink BWP).

[0140] One or more BWP indicator fields can be provided in the downlink control information (DCI). The value of the BWP indicator field can indicate which BWP in the set of configured BWPs is the active downlink BWP for one or more downlink receptions. The value of the one or more BWP indicator fields can indicate the active uplink BWP for one or more uplink transmissions.

[0141] The base station can semi-statically configure a default downlink BWP for the UE within a set of configured downlink BWPs associated with the PCell. If the base station does not provide a default downlink BWP to the UE, the default downlink BWP can be the initial active downlink BWP. The UE can determine which BWP is the initial active downlink BWP based on the CORESET configuration obtained using the PBCH.

[0142] The base station can configure the BWP inactivity timer value for the UE for the PCell. The UE can start or restart the BWP inactivity timer at any appropriate time. For example, the UE can start or restart the BWP inactivity timer when: (a) the UE detects a DCI indicating an active downlink BWP other than the default downlink BWP for paired spectrum operation; or (b) the UE detects a DCI indicating an active downlink BWP or active uplink BWP other than the default downlink BWP or uplink BWP for unpaired spectrum operation. If the UE does not detect a DCI within a time interval (e.g., 1 ms or 0.5 ms), the UE can run the BWP inactivity timer toward its expiration (e.g., an increment from zero to the BWP inactivity timer value, or a decrement from the BWP inactivity timer value to zero). When the BWP inactivity timer expires, the UE can switch from the active downlink BWP to the default downlink BWP.

[0143] In the example, the base station can semi-statically configure the UE using one or more BWPs. The UE can switch the active BWP from the first BWP to the second BWP in response to receiving a DCI indicating that the second BWP is the active BWP and / or in response to the expiration of a BWP inactivity timer (e.g., in the case that the second BWP is the default BWP).

[0144] Downlink and uplink BWP handovers can be performed independently in paired spectrum (where BWP handover refers to switching from the currently active BWP to a non-currently active BWP). In unpaired spectrum, downlink and uplink BWP handovers can be performed simultaneously. Handovers can occur between configured BWPs based on RRC signaling, DCI, the expiration of a BWP inactivity timer, and / or the initiation of random access.

[0145] Figure 9 An example of bandwidth adaptation using three configured BWPs on an NR carrier is shown. A UE configured with these three BWPs can switch from one BWP to another at a handover point. Figure 9 In the example shown, the BWPs include: BWP902 with a bandwidth of 40MHz and a subcarrier spacing of 15kHz; BWP904 with a bandwidth of 10MHz and a subcarrier spacing of 15kHz; and BWP906 with a bandwidth of 20MHz and a subcarrier spacing of 60kHz. BWP902 can be the initial active BWP, and BWP904 can be the default BWP. The UE can switch between BWPs at a handover point. Figure 9 In the example, the UE can switch from BWP 902 to BWP 904 at handover point 908. The handover at handover point 908 can occur for any suitable reason, such as in response to the expiration of a BWP inactivity timer (indicating a switch to the default BWP) and / or in response to receiving a DCI indicating that BWP 904 is the active BWP. The UE can switch from active BWP 904 to BWP 906 at handover point 910 in response to receiving a DCI indicating that BWP 906 is the active BWP. The UE can switch from active BWP 906 to BWP 904 at handover point 912 in response to the expiration of a BWP inactivity timer and / or in response to receiving a DCI indicating that BWP 904 is the active BWP. The UE can switch from active BWP 904 to BWP 902 at handover point 914 in response to receiving a DCI indicating that BWP 902 is the active BWP.

[0146] If a UE is configured for a secondary cell with a default downlink BWP and timer values ​​from a set of configured downlink BWPs, the UE procedure for switching BWPs on the secondary cell can be the same as / similar to that on the primary cell. For example, the UE can use these values ​​on the secondary cell in the same / similar way as the UE would use the timer values ​​and default downlink BWP of the primary cell.

[0147] To provide higher data rates, carrier aggregation (CA) can be used to combine two or more carriers and transmit them simultaneously to / from the same UE. The aggregated carriers in CA can be referred to as component carriers (CCs). When using CA, there are multiple serving cells for the UE, one serving cell per CC. A CC can have three configurations in the frequency domain.

[0148] Figure 10A Three CA configurations with two CCs are shown. In the intra-band contiguous configuration 1002, the two CCs are aggregated in the same frequency band (band A) and located directly adjacent to each other within the band. In the intra-band discontinuous configuration 1004, the two CCs are aggregated in a frequency band (band A) and separated by a certain gap within the band. In the inter-band configuration 1006, the two CCs are located in frequency bands (band A and band B).

[0149] In the example, up to 32 CCs can be aggregated. Aggregated CCs can have the same or different bandwidths, subcarrier spacings, and / or duplex schemes (TDD or FDD). The serving cell for the UE using CA can have downlink CCs. For FDD, one or more uplink CCs can optionally be configured for the serving cell. For example, the ability to aggregate more downlink carriers than uplink carriers can be useful when the UE has more data traffic in the downlink than in the uplink.

[0150] When using CA, one of the aggregated cells used for the UE can be referred to as the primary cell (PCell). The PCell can be the serving cell to which the UE initially connects during RRC connection establishment, re-establishment, and / or handover. The PCell provides the UE with NAS mobility information and security input. The UE can have different PCells. In the downlink, the carrier corresponding to the PCell can be referred to as the downlink primary CC (DL PCC). In the uplink, the carrier corresponding to the PCell can be referred to as the uplink primary CC (UL PCC). Other aggregated cells used for the UE can be referred to as secondary cells (SCells). In the example, the SCell can be configured after the PCell is configured for the UE. For example, the SCell can be configured via an RRC connection reconfiguration procedure. In the downlink, the carrier corresponding to the SCell can be referred to as the downlink secondary CC (DL SCC). In the uplink, the carrier corresponding to the SCell can be referred to as the uplink secondary CC (UL SCC).

[0151] Configurable SCells for a UE can be activated and deactivated based on factors such as traffic and channel conditions. Deactivating an SCell can mean ceasing PDCCH and PDSCH reception on the SCell, and ceasing PUSCH, SRS, and CQI transmissions on the SCell. (The remaining text appears to be incomplete and requires further context.) Figure 4B The MAC CE is used to activate and deactivate configured SCells. For example, the MAC CE can use a bitmap (e.g., one bit per SCell) to indicate which SCells for the UE (e.g., in a subset of configured SCells) are activated or deactivated. Configured SCells can be deactivated in response to the expiration of a SCell deactivation timer (e.g., one SCell deactivation timer per SCell).

[0152] Downlink control information for a cell (such as scheduling assignments and scheduling grants) can be transmitted on the cell corresponding to the assignment and grant, a process known as self-scheduling. A cell's DCI can be transmitted on another cell, a process known as cross-carrier scheduling. Uplink control information used for aggregation cells (e.g., HARQ acknowledgments and channel state feedback, such as CQI, PMI, and / or RI) can be transmitted on the PCell's PUCCH. For a large number of aggregated downlink CCs, the PCell's PUCCH may become overloaded. Cells can be divided into multiple PUCCH groups.

[0153] Figure 10B This illustrates an example of how aggregated cells can be configured into one or more PUCCH groups. PUCCH group 1010 and PUCCH group 1050 can each include one or more downlink CCs. Figure 10BIn the example, PUCCH group 1010 includes three downlink CCs: PCell 1011, SCell 1012, and SCell 1013. PUCCH group 1050 in this example includes three downlink CCs: PCell 1051, SCell 1052, and SCell 1053. One or more uplink CCs can be configured as PCell 1021, SCell 1022, and SCell 1023. One or more other uplink CCs can be configured as primary Scell ​​(PSCell) 1061, SCell 1062, and SCell 1063. Uplink control information (UCI) related to the downlink CCs of PUCCH group 1010 (shown as UCI 1031, UCI 1032, and UCI 1033) can be transmitted in the uplink of PCell 1021. Uplink control information (UCI) related to the downlink CC of PUCCH group 1050 (shown as UCI 1071, UCI 1072, and UCI 1073) can be transmitted in the uplink of PSCell 1061. In the example, if Figure 10B If the aggregation unit depicted is not divided into PUCCH group 1010 and PUCCH group 1050, a single uplink PCell will transmit UCI associated with the downlink CC, and that PCell may become overloaded. Overload can be prevented by dividing the transmission of UCI between PCell 1021 and PSCell 1061.

[0154] A physical cell ID and a cell index can be assigned to a cell that includes a downlink carrier and an optional uplink carrier. The physical cell ID or cell index can identify the cell's downlink carrier and / or uplink carrier, for example, depending on the context in which the physical cell ID is used. The physical cell ID can be determined using synchronization signals transmitted on the downlink component carrier. The cell index can be determined using RRC messages. In this disclosure, the physical cell ID can be referred to as a carrier ID, and the cell index can be referred to as a carrier index. For example, when this disclosure relates to a first physical cell ID for a first downlink carrier, this disclosure can mean that the first physical cell ID is used for a cell that includes the first downlink carrier. The same / similar concepts can be applied, for example, to carrier activation. When this disclosure indicates that a first carrier is activated, this specification can mean that a cell including that first carrier is activated.

[0155] In CA, the multi-carrier nature of the PHY can be exposed to the MAC. In the example, the HARQ entity can operate on the serving cell. Transport modules can be generated based on the assignment / license of each serving cell. The transport module and its potential HARQ retransmissions can be mapped to the serving cell.

[0156] In the downlink, the base station can transmit one or more reference signals (RS) (e.g., unicast, multicast, and / or broadcast) to the UE (e.g., PSS, SSS, CSI-RS, DMRS, and / or PT-RS, such as...). Figure 5A (As shown). In the uplink, the UE can transmit one or more RSs to the base station (e.g., DMRS, PT-RS, and / or SRS, such as...). Figure 5B (As shown). PSS and SSS can be transmitted by the base station and used by the UE to synchronize the UE with the base station. PSS and SSS can be provided in a synchronization signal (SS) / physical broadcast channel (PBCH) block that includes PSS, SSS, and PBCH. The base station can periodically transmit bursts of SS / PBCH blocks.

[0157] Figure 11A An example of the structure and location of SS / PBCH blocks is shown. A burst of SS / PBCH blocks can include one or more SS / PBCH blocks (e.g., 4 SS / PBCH blocks, such as...). Figure 11A (As shown). Bursts can be transmitted periodically (e.g., every 2 frames or 20 ms). Bursts can be limited to half-frames (e.g., the first half-frame lasting 5 ms). It should be understood that... Figure 11A This is an example, and these parameters (the number of SS / PBCH blocks per burst, the periodicity of the burst, the burst location within a frame) can be configured based on, for example, the carrier frequency of the cell in which the SS / PBCH blocks are transmitted; the cell's parameter set or subcarrier spacing; configuration performed by the network (e.g., using RRC signaling); or any other suitable factor. In the example, the UE can assume the subcarrier spacing of the SS / PBCH blocks based on the carrier frequency being monitored, unless the radio network configures the UE to assume a different subcarrier spacing.

[0158] SS / PBCH blocks can span one or more OFDM symbols in the time domain (e.g., 4 OFDM symbols, such as...). Figure 11A As shown in the example, and can span one or more subcarriers in the frequency domain (e.g., 240 consecutive subcarriers). PSS, SSS, and PBCH can have a common center frequency. PSS can be transmitted first and can span, for example, 1 OFDM symbol and 127 subcarriers. SSS can be transmitted after PSS (e.g., after two symbols) and can span 1 OFDM symbol and 127 subcarriers. PBCH can be transmitted after PSS (e.g., spanning the next 3 OFDM symbols) and can span 240 subcarriers.

[0159] The UE may not know the location of the SS / PBCH block in the time and frequency domains (e.g., when the UE is searching for a cell). To find and select a cell, the UE can monitor the carrier of the PSS. For example, the UE can monitor the frequency location within the carrier. If the PSS is not found after a certain duration (e.g., 20 ms), the UE can search for the PSS at different frequency locations within the carrier, as indicated by the synchronization grating. If the PSS is found at a certain location in the time and frequency domains, the UE can determine the locations of the SSS and PBCH based on the known structure of the SS / PBCH block, respectively. The SS / PBCH block can be a cell-defined SS block (CD-SSB). In the example, the primary cell can be associated with the CD-SSB. The CD-SSB can be located on the synchronization grating. In the example, cell selection / search and / or reselection can be based on the CD-SSB.

[0160] The SS / PBCH block can be used by the UE to determine one or more parameters of the cell. For example, the UE can determine the physical cell identifier (PCI) of the cell based on the sequence of PSS and SSS, respectively. The UE can determine the location of the cell's frame boundary based on the location of the SS / PBCH block. For example, the SS / PBCH block can indicate that it has been transmitted according to a transmission mode in which the SS / PBCH block is at a known distance from the frame boundary.

[0161] The PBCH can use QPSK modulation and forward error correction (FEC). FEC can use polarity coding. One or more symbols spanned by the PBCH can carry one or more DMRS for PBCH demodulation. The PBCH can include an indication of the cell's current system frame number (SFN) and / or an SS / PBCH block timing index. These parameters can help the UE synchronize time with the base station. The PBCH can include a Master Information Block (MIB) to provide one or more parameters to the UE. The MIB can be used by the UE to locate the Residual Minimum System Information (RMSI) associated with the cell. The RMSI can include System Information Block Type 1 (SIB1). SIB1 can contain information required for the UE to access the cell. The UE can use one or more parameters of the MIB to monitor the PDCCH that can be used to schedule the PDSCH. The PDSCH can include SIB1. SIB1 can be decoded using the parameters provided in the MIB. The PBCH can indicate that SIB1 does not exist. Based on the PBCH indicating that SIB1 does not exist, the UE can point to a frequency. The UE can search for SS / PBCH blocks at the frequency pointed to by the UE.

[0162] The UE may assume that one or more SS / PBCH blocks transmitted using the same SS / PBCH block index are quasi-co-located (QCLed) (e.g., having the same / similar Doppler spread, Doppler shift, average gain, average delay, and / or spatial Rx parameters). The UE may not assume QCL for SS / PBCH blocks transmitted with different SS / PBCH block indices.

[0163] SS / PBCH blocks (e.g., those within a half-frame) can be transmitted in spatial directions (e.g., using different beams across the coverage area of ​​the cell). In the example, the first SS / PBCH block can be transmitted in the first spatial direction using the first beam, and the second SS / PBCH block can be transmitted in the second spatial direction using the second beam.

[0164] In the example, within the carrier's frequency range, the base station can transmit multiple SS / PBCH blocks. In the example, the first PCI of the first SS / PBCH block of these multiple SS / PBCH blocks can be different from the second PCI of the second SS / PBCH block of these multiple SS / PBCH blocks. The PCIs of SS / PBCH blocks transmitted at different frequency locations can be different or the same.

[0165] CSI-RS can be transmitted by the base station and used by the UE to acquire Channel State Information (CSI). The base station can utilize one or more CSI-RS to configure the UE for channel estimation or any other suitable purpose. The base station can utilize one or more of the same / similar CSI-RS to configure the UE. The UE can measure the one or more CSI-RS. The UE can estimate the downlink channel state and / or generate a CSI report based on the measurements of the one or more downlink CSI-RS. The UE can provide the CSI report to the base station. The base station can use the feedback provided by the UE (e.g., the estimated downlink channel state) to perform link adaptation.

[0166] The base station can semi-statically configure the UE using one or more CSI-RS resource sets. CSI-RS resources can be associated with location and periodicity in the time and frequency domains. The base station can selectively activate and / or deactivate CSI-RS resources. The base station can instruct the UE that CSI-RS resources in the CSI-RS resource set are activated and / or deactivated.

[0167] The base station can configure the UE to report CSI measurements. The base station can configure the UE to provide CSI reports periodically, aperiodically, or semi-persistently. For periodic CSI reporting, the UE can be configured with multiple CSI reports at specific times and / or periodically. For aperiodic CSI reporting, the base station can request CSI reports. For example, the base station can command the UE to measure configured CSI-RS resources and provide CSI reports related to the measurements. For semi-persistent CSI reporting, the base station can configure the UE to transmit periodically and selectively activate or deactivate periodic reports. The base station can configure the UE using CSI-RS resource sets and CSI reports using RRC signaling.

[0168] CSI-RS configuration may include one or more parameters indicating, for example, up to 32 antenna ports. The UE can be configured to use the same OFDM symbols for both the downlink CSI-RS and the control resource set (CORESET) when the downlink CSI-RS and CORESET are spatially QCLed and the resource elements associated with the downlink CSI-RS are outside the physical resource block (PRB) configured for the CORESET. The UE can also be configured to use the same OFDM symbols for both the downlink CSI-RS and the SS / PBCH block when the downlink CSI-RS and SS / PBCH block are spatially QCLed and the resource elements associated with the downlink CSI-RS are outside the PRB configured for the SS / PBCH block.

[0169] Downlink DMRS can be transmitted by the base station and used by the UE for channel estimation. For example, downlink DMRS can be used for consistent demodulation of one or more downlink physical channels (e.g., PDSCH). The NR network can support one or more variable and / or configurable DMRS modes for data demodulation. At least one downlink DMRS configuration can support a preceding DMRS mode. The preceding DMRS can be mapped on one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). The base station can semi-statically configure the UE using the number (e.g., maximum number) of preceding DMRS symbols used for PDSCH. The DMRS configuration can support one or more DMRS ports. For example, for single-user MIMO, the DMRS configuration can support up to eight orthogonal downlink DMRS ports per UE. For multi-user MIMO, the DMRS configuration can support up to four orthogonal downlink DMRS ports per UE. The radio network can (e.g., at least for CP-OFDM) support a common DMRS structure for downlink and uplink, where DMRS locations, DMRS modes, and / or scrambling sequences can be the same or different. The base station can use the same precoding matrix to transmit downlink DMRS and the corresponding PDSCH. The UE can use one or more downlink DMRS to perform consistent demodulation / channel estimation of the PDSCH.

[0170] In the example, the transmitter (e.g., a base station) can use a precoder matrix for a portion of the transmission bandwidth. For example, the transmitter can use a first precoder matrix for a first bandwidth and a second precoder matrix for a second bandwidth. The first and second precoder matrices can differ based on the first and second bandwidths being different. The UE can assume that the same precoder matrix is ​​used across the set of PRBs. This set of PRBs can be represented as a Precoder Resource Block Group (PRG).

[0171] A PDSCH may include one or more layers. The UE may assume that at least one symbol with DMRS exists on one or more layers of the PDSCH. A higher layer may configure up to three DMRS for the PDSCH.

[0172] Downlink PT-RS can be transmitted by the base station and used by the UE for phase noise compensation. The presence of downlink PT-RS can depend on RRC configuration. The presence and / or mode of downlink PT-RS can be configured based on the UE through a combination of RRC signaling and / or association with one or more parameters that can be indicated by DCI for other purposes (e.g., modulation and coding scheme (MCS)). When configured, the dynamic presence of downlink PT-RS can be associated with one or more DCI parameters including at least one MCS. NR networks can support multiple PT-RS densities defined in the time / frequency domain. When present, the frequency domain density can be associated with at least one configuration of the scheduled bandwidth. The UE can employ the same precoding for both DMRS ports and PT-RS ports. The number of PT-RS ports can be less than the number of DMRS ports in the scheduled resources. Downlink PT-RS can be restricted to the UE's scheduled time / frequency duration. Downlink PT-RS can be transmitted on symbols to facilitate phase tracking at the receiver.

[0173] The UE can transmit uplink DMRS to the base station for channel estimation. For example, the base station can use uplink DMRS to perform consistent demodulation of one or more uplink physical channels. For example, the UE can transmit uplink DMRS with PUSCH and / or PUCCH. Uplink DMRS can span a frequency range similar to the frequency range associated with the corresponding physical channel. The base station can configure the UE using one or more uplink DMRS configurations. At least one DMRS configuration can support a frontload DMRS mode. Frontload DMRS can be mapped on one or more OFDM symbols (e.g., one or two adjacent OFDM symbols). One or more uplink DMRS can be configured to be transmitted at one or more symbols of PUSCH and / or PUCCH. The base station can semi-statically configure the UE with the number (e.g., maximum number) of frontload DMRS symbols for PUSCH and / or PUCCH, which the UE can use to schedule single-symbol DMRS and / or dual-symbol DMRS. NR networks can support (e.g., for Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM)) a common DMRS structure for both downlink and uplink, where the DMRS location, DMRS mode, and / or DMRS perturbation sequence can be the same or different.

[0174] A PUSCH may include one or more layers, and a UE may transmit at least one symbol having DMRS on one or more layers present in the PUSCH. In the example, a higher layer may configure up to three DMRS for the PUSCH.

[0175] Depending on the UE's RRC configuration, uplink PT-RS (which can be used by the base station for phase tracking and / or phase noise compensation) may or may not be present. The presence and / or mode of uplink PT-RS can be configured based on the UE through a combination of RRC signaling and / or one or more parameters indicated by the DCI for other purposes (e.g., modulation and coding scheme (MCS)). When configured, the dynamic presence of uplink PT-RS can be associated with one or more DCI parameters including at least one MCS. The radio network can support multiple uplink PT-RS densities defined in the time / frequency domain. When present, the frequency domain density can be associated with at least one configuration of the scheduled bandwidth. The UE can use the same precoding for both DMRS ports and PT-RS ports. The number of PT-RS ports can be less than the number of DMRS ports in the scheduled resources. For example, uplink PT-RS can be restricted to the UE's scheduled time / frequency duration.

[0176] The UE can transmit SRS to the base station for channel state estimation to support uplink channel-dependent scheduling and / or link adaptation. The SRS transmitted by the UE allows the base station to estimate the uplink channel state at one or more frequencies. The scheduler at the base station can use the estimated uplink channel state to assign one or more resource blocks to uplink PUSCH transmissions from the UE. The base station can semi-statically configure the UE using one or more SRS resource sets. For each SRS resource set, the base station can configure the UE using one or more SRS resources. SRS resource set suitability can be configured by higher-layer (e.g., RRC) parameters. For example, when higher-layer parameters indicate beam management, SRS resources in the SRS resource sets of the one or more SRS resource sets (e.g., having the same / similar time-domain behavior, periodic, aperiodic, etc.) can be transmitted at certain times (e.g., simultaneously). The UE can transmit one or more SRS resources from the SRS resource set. The NR network can support aperiodic, periodic, and / or semi-persistent SRS transmissions. The UE can transmit SRS resources based on one or more trigger types, where the trigger types may include higher-layer signaling (e.g., RRC) and / or one or more DCI formats. In the example, at least one DCI format may be used for the UE to select at least one configured SRS resource set from one or more configured SRS resource sets. SRS trigger type 0 may refer to SRS triggered based on higher-layer signaling. SRS trigger type 1 may refer to SRS triggered based on one or more DCI formats. In the example, when PUSCH and SRS are transmitted in the same time slot, the UE can be configured to transmit SRS after the transmission of PUSCH and the corresponding uplink DMRS.

[0177] The base station can semi-statically configure the UE using one or more SRS configuration parameters indicating at least one of the following: SRS resource configuration identifier; number of SRS ports; time-domain behavior of SRS resource configuration (e.g., indication of periodic, semi-persistent, or aperiodic SRS); time slot, micro-time slot, and / or subframe level periodicity; time slots of periodic and / or aperiodic SRS resources; number of OFDM symbols in SRS resources; initiating OFDM symbols for SRS resources; SRS bandwidth; frequency hopping bandwidth; cyclic shift; and / or SRS sequence ID.

[0178] An antenna port is defined such that a symbol on the antenna port, through the channel through which it is transmitted, can be inferred from another symbol on the same antenna port, through the same channel through which it is transmitted. If a first symbol and a second symbol are transmitted on the same antenna port, the receiver can infer the channel used to transmit the second symbol on the antenna port (e.g., fade gain, multipath delay, etc.) from the channel used to transmit the first symbol on the antenna port. A first antenna port and a second antenna port can be referred to as quasi-co-located (QCLed) if one or more large-scale properties can be inferred from the channel through which the second symbol on the second antenna port is transmitted. These one or more large-scale properties may include at least one of the following: delay spread; Doppler spread; Doppler shift; average gain; average delay; and / or spatial reception (Rx) parameters.

[0179] Channels using beamforming require beam management. Beam management can include beam measurement, beam selection, and beam indication. A beam can be associated with one or more reference signals. For example, a beam can be identified by one or more beamforming reference signals. The UE can perform downlink beam measurements and generate a beam measurement report based on downlink reference signals (e.g., Channel State Information Reference Signal (CSI-RS)). After setting up an RRC connection with the base station, the UE can perform the downlink beam measurement procedure.

[0180] Figure 11B An example of a Channel State Information Reference Signal (CSI-RS) mapped in the time and frequency domains is shown. Figure 11BThe square shown may represent a resource block (RB) within the cell's bandwidth. The base station may transmit one or more RRC messages including CSI-RS resource configuration parameters indicating one or more CSI-RS. One or more of the following parameters can be configured for CSI-RS resource configuration via higher-layer signaling (e.g., RRC and / or MAC signaling): CSI-RS resource configuration identity, number of CSI-RS ports, CSI-RS configuration (e.g., symbol and resource element (RE) positions in subframes), CSI-RS subframe configuration (e.g., subframe position, offset, and periodicity in radio frames), CSI-RS power parameters, CSI-RS sequence parameters, Code Division Multiplexing (CDM) type parameters, frequency density, transport comb, Quasi-Co-location (QCL) parameters (e.g., QCL-scramblingidentity, crs-portscount, mbsfn-subframeconfiglist, csi-rs-configZPid, qcl-csi-rs-configNZPid), and / or other radio resource parameters.

[0181] Figure 11B The three beams shown can be configured for use in a UE-specific configuration. Figure 11B The diagram shows three beams (beam #1, beam #2, and beam #3), with the possibility of configuring more or fewer beams. CSI-RS1101 can be assigned to beam #1, which can be transmitted on one or more subcarriers in the RB of the first symbol. CSI-RS1102 can be assigned to beam #2, which can be transmitted on one or more subcarriers in the RB of the second symbol. CSI-RS1103 can be assigned to beam #3, which can be transmitted on one or more subcarriers in the RB of the third symbol. By using frequency division multiplexing (FDM), the base station can use other subcarriers in the same RB (e.g., those not used to transmit CSI-RS1101) to transmit another CSI-RS associated with a beam of another UE. By using time domain multiplexing (TDM), the beam for a UE can be configured such that the beam for the UE uses symbols from beams of other UEs.

[0182] CSI-RS, such as Figure 11BThose shown (e.g., CSI-RS1101, 1102, 1103) can be transmitted by the base station and used by the UE for one or more measurements. For example, the UE can measure the Reference Signal Received Power (RSRP) of a configured CSI-RS resource. The base station can configure the UE using a reporting configuration, and the UE can report RSRP measurements to the network (e.g., via one or more base stations) based on the reporting configuration. In the example, the base station can determine one or more Transmission Configuration Indication (TCI) states, including multiple reference signals, based on the reported measurement results. In the example, the base station can indicate one or more TCI states to the UE (e.g., via RRC signaling, MAC CE, and / or DCI). The UE can receive downlink transmissions with a receive (Rx) beam determined based on the one or more TCI states. In the example, the UE may or may not have beam correspondence capability. If the UE has beam correspondence capability, the UE can determine the spatial domain filter for the transmit (Tx) beam based on the spatial domain filter corresponding to the Rx beam. If the UE does not have beam correspondence capability, the UE can perform an uplink beam selection procedure to determine the spatial domain filter for the Tx beam. The UE can perform the uplink beam selection procedure based on one or more Sounding Reference Signal (SRS) resources configured for the UE by the base station. The base station can select and indicate the UE's uplink beam based on measurements of one or more SRS resources transmitted by the UE.

[0183] In the beam management procedure, the UE can assess (e.g., measure) the channel quality of one or more beampup links, including beampup links containing transmit beams transmitted by the base station, and receive beams received by the UE. Based on this assessment, the UE can transmit a beam measurement report indicating one or more beampup quality parameters, including, for example, one or more beam identifiers (e.g., beam index, reference signal index, etc.), RSRP, precoding matrix indicator (PMI), channel quality indicator (CQI), and / or rank indicator (RI).

[0184] Figure 12AExamples of three downlink beam management procedures are shown: P1, P2, and P3. Procedure P1 can enable UE measurement of the transmit (Tx) beams for a Transport Receive Point (TRP) (or multiple TRPs), for example, to support the selection of one or more base station Tx beams and / or UE Rx beams (shown as ellipses in the top and bottom rows of P1, respectively). Beamforming at the TRP can include Tx beam sweeping for the beam set (shown as an ellipse rotating counterclockwise in the top rows of P1 and P2, indicated by the dashed arrows). Beamforming at the UE can include Rx beam sweeping for the beam set (shown as an ellipse rotating clockwise in the bottom rows of P1 and P3, indicated by the dashed arrows). Procedure P2 can be used to enable UE measurement of the Tx beams for a TRP (shown as an ellipse rotating counterclockwise in the top row of P2, indicated by the dashed arrows). The UE and / or base station may perform procedure P2 using a smaller beam set than that used in procedure P1, or using a narrower beam than that used in procedure P1. This may be referred to as beam refinement. The UE may perform procedure P3 for Rx beam determination by using the same Tx beam at the base station and sweeping the Rx beam at the UE.

[0185] Figure 12B Examples of three uplink beam management procedures are shown: U1, U2, and U3. Procedure U1 can be used to enable the base station to perform measurements on the UE's Tx beam, for example, to support the selection of one or more UE Tx beams and / or base station Rx beams (shown as ellipses in the top and bottom rows of U1, respectively). Beamforming at the UE can include, for example, an Rx beam sweep from the beam set (shown as an ellipse rotating clockwise in the bottom rows of U1 and U3, indicated by the dashed arrow). Beamforming at the base station can include, for example, an Rx beam sweep from the beam set (shown as an ellipse rotating counterclockwise in the top rows of U1 and U2, indicated by the dashed arrow). When the UE uses a fixed Tx beam, procedure U2 can be used to enable the base station to adjust its Rx beam. The UE and / or base station can perform procedure U2 using a smaller beam set than that used in procedure P1, or using a narrower beam than that used in procedure P1. This can be called beam refinement. The UE can execute procedure U3 to adjust its Tx beam when the base station is using a fixed Rx beam.

[0186] The UE can initiate a beam fault recovery (BFR) procedure based on the detection of a beam fault. The UE can transmit a BFR request (e.g., preamble, UCI, SR, MAC CE, etc.) based on the initiation of the BFR procedure. The UE can detect a beam fault based on the determination that the quality of the beam pair link in the associated control channel is unsatisfactory (e.g., an error rate higher than the error rate threshold, received signal power lower than the received signal power threshold, timer expiration, etc.).

[0187] The UE can use one or more reference signals (RS) to measure the quality of the beamp-link, which may include one or more SS / PBCH blocks, one or more CSI-RS resources, and / or one or more demodulation reference signals (DMRS). The quality of the beamp-link can be based on one or more of the following: block error rate (BLER), RSRP value, signal-to-interference-plus-noise ratio (SINR) value, reference signal reception quality (RSRQ) value, and / or CSI value measured on the RS resources. The base station may indicate one or more DM-RS quasi-co-located (QCLed) RS resources and channels (e.g., control channels, shared data channels, etc.). The one or more DMRS of the RS resources and channels may be QCLed when the channel characteristics (e.g., Doppler shift, Doppler spread, average delay, delay spread, spatial Rx parameter, fading, etc.) from the transmission to the UE via the RS resources are similar to or the same as the channel characteristics from the transmission to the UE via the channels.

[0188] The network (e.g., gNB and / or the network's ng-eNB) and / or the UE can initiate a random access procedure. A UE in the RRC_IDLE state and / or RRC_INACTIVE state can initiate a random access procedure to request connection settings to the network. A UE can initiate a random access procedure from the RRC_CONNECTED state. A UE can initiate a random access procedure to request uplink resources (e.g., for uplink transmission of SR when no PUCCH resources are available) and / or to acquire uplink timing (e.g., when the uplink synchronization state is not synchronized). A UE can initiate a random access procedure to request one or more System Information Blocks (SIBs) (e.g., other system information such as SIB2, SIB3, etc.). A UE can initiate a random access procedure for beam fault recovery requests. The network can initiate random access procedures for handover and / or for establishing time comparisons for SCell additions.

[0189] Figure 13A A four-step contention-based random access procedure is shown. Before initiating this procedure, the base station may transmit configuration message 1310 to the UE. Figure 13AThe procedure shown involves the transmission of four messages: Msg 1 1311, Msg 2 1312, Msg 3 1313, and Msg 4 1314. Msg 1 1311 may include and / or be referred to as a preamble (or random access preamble). Msg 2 1312 may include and / or be referred to as a random access response (RAR).

[0190] Configuration message 1310 may be transmitted, for example, using one or more RRC messages. These one or more RRC messages may indicate one or more Random Access Channel (RACH) parameters to the UE. These one or more RACH parameters may include at least one of the following: general parameters for one or more random access procedures (e.g., RACH-configGeneral); cell-specific parameters (e.g., RACH-ConfigCommon); and / or dedicated parameters (e.g., RACH-configDedicated). The base station may broadcast or multicast these one or more RRC messages to one or more UEs. These one or more RRC messages may be UE-specific (e.g., dedicated RRC messages transmitted to the UE in the RRC_CONNECTED state and / or RRC_INACTIVE state). The UE may determine the time and frequency resources and / or uplink transmission power for transmitting Msg 1 1311 and / or Msg 3 1313 based on these one or more RACH parameters. Based on these one or more RACH parameters, the UE may determine the receive timing and downlink channel for receiving Msg 2 1312 and Msg 4 1314.

[0191] The one or more RACH parameters provided in configuration message 1310 may indicate one or more physical RACH (PRACH) timings available for transmitting Msg 11311. These one or more PRACH timings may be predefined. These one or more RACH parameters may indicate one or more available sets of one or more PRACH timings (e.g., prach-ConfigIndex). These one or more RACH parameters may indicate a relationship between (a) one or more PRACH timings and (b) one or more reference signals. These one or more RACH parameters may indicate a relationship between (a) one or more preambles and (b) one or more reference signals. These one or more reference signals may be SS / PBCH blocks and / or CSI-RS. For example, these one or more RACH parameters may indicate the number of SS / PBCH blocks mapped to PRACH timings and / or the number of preambles mapped to SS / PBCH blocks.

[0192] The one or more RACH parameters provided in configuration message 1310 can be used to determine the uplink transmission power of Msg 1 1311 and / or Msg 3 1313. For example, the one or more RACH parameters can indicate a reference power for preamble transmission (e.g., the received target power and / or the initial power of the preamble transmission). One or more power offsets indicated by the one or more RACH parameters may exist. For example, the one or more RACH parameters can indicate: power ramp step size; power offset between SSB and CSI-RS; power offset between transmissions of Msg 1 1311 and Msg 3 1313; and / or power offset values ​​between preamble groups. The one or more RACH parameters can indicate one or more thresholds upon which the UE can determine at least one reference signal (e.g., SSB and / or CSI-RS) and / or uplink carrier (e.g., normal uplink (NUL) carrier and / or supplementary uplink (SUL) carrier).

[0193] Msg 1 1311 may include one or more preamble transmissions (e.g., preamble transmission and one or more preamble retransmissions). The RRC message may be used to configure one or more preamble groups (e.g., group A and / or group B). A preamble group may include one or more preambles. The UE may determine the preamble group based on path loss measurements and / or the magnitude of Msg 3 1313. The UE may measure the RSRP of one or more reference signals (e.g., SSB and / or CSI-RS) and determine at least one reference signal with an RSRP higher than an RSRP threshold (e.g., rsrp-ThresholdSSB and / or rsrp-ThresholdCSI-RS). For example, if the association between the one or more preambles and the at least one reference signal is configured by the RRC message, the UE can select at least one preamble associated with the one or more reference signals and / or the selected preamble group.

[0194] The UE can determine the preamble based on the one or more RACH parameters provided in configuration message 1310. For example, the UE can determine the preamble based on path loss measurement, RSRP measurement, and / or the size of Msg 3 1313. As another example, the one or more RACH parameters can indicate: the preamble format; the maximum number of preamble transmissions; and / or one or more thresholds for determining one or more preamble groups (e.g., group A and group B). The base station can use the one or more RACH parameters to configure an association between one or more preambles and one or more reference signals (e.g., SSB and / or CSI-RS) for the UE. If the association is configured, the UE can determine the preamble included in Msg 1 1311 based on the association. Msg 1 1311 can be transmitted to the base station via one or more PRACH timings. The UE can use one or more reference signals (e.g., SSB and / or CSI-RS) for selecting the preamble and for determining the PRACH timing. One or more RACH parameters (e.g., ra-ssb-OccasionMskIndex and / or ra-OccasionList) can indicate the association between the PRACH timing and the one or more reference signals.

[0195] If no response is received after the preamble transmission, the UE may perform a preamble retransmission. The UE may increase the uplink transmission power used for the preamble retransmission. The UE may select the initial preamble transmission power based on path loss measurements and / or the target received preamble power configured by the network. The UE may determine the preamble to be retransmitted and may ramp up the uplink transmission power. The UE may receive one or more RACH parameters (e.g., PREAMBLE_POWER_RAMPING_STEP) indicating the ramp step size used for the preamble retransmission. The ramp step size may be the amount by which the uplink transmission power used for the retransmission is incrementally increased. If the UE determines that the same reference signal (e.g., SSB and / or CSI-RS) is used as in the previous preamble transmission, the UE may ramp up the uplink transmission power. The UE may count the number of preamble transmissions and / or retransmissions (e.g., PREAMBLE_TRANSMISSION_COUNTER). For example, if the number of preamble transmissions exceeds a threshold configured by one or more RACH parameters (e.g., preambleTransMax), the UE can determine that the random access procedure has not been successfully completed.

[0196] The Msg 2 1312 received by the UE may include a RAR. In some scenarios, Msg 2 1312 may include multiple RARs corresponding to multiple UEs. Msg 2 1312 may be received after or in response to the transmission of Msg 1 1311. Msg 2 1312 may be scheduled on the DL-SCH and indicated on the PDCCH using a Random Access RNTI (RA-RNTI). Msg 2 1312 may indicate that Msg 1 1311 was received by the base station. Msg 2 1312 may include a time comparison command that the UE can use to adjust the transmission timing of the UE, a scheduling grant for transmitting Msg 3 1313, and / or a Temporary Cell RNTI (TC-RNTI). After transmitting the preamble, the UE may initiate a time window (e.g., ra-ResponseWindow) to monitor the PDCCH of Msg 2 1312. The UE may determine when to initiate the time window based on the timing of the PRACH used by the UE to transmit the preamble. For example, the UE may initiate a time window of one or more symbols after the last symbol of the preamble (e.g., at the first PDCCH timing starting from the end of the preamble transmission). These one or more symbols may be determined based on a set of parameters. The PDCCH may be in a common search space configured by RRC messages (e.g., a Type 1-PDCCH common search space). The UE may identify the RAR based on a Radio Network Temporary Identifier (RNTI). The RNTI may be used depending on one or more events that initiate the random access procedure. The UE may use a Random Access RNTI (RA-RNTI). The RA-RNTI may be associated with the PRACH timing in which the UE transmits the preamble. For example, the UE may determine the RA-RNTI based on: the OFDM symbol index; the time slot index; the frequency domain index; and / or the UL carrier indicator of the PRACH timing. An example of an RA-RNTI may be as follows:

[0197] RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id

[0198] , where s_id can be the index of the first OFDM symbol of the PRACH timing (e.g., 0 ≤ s_id < 14), t_id can be the index of the first slot of the PRACH timing in the system frame (e.g., 0 ≤ t_id < 80), f_id can be the index of the PRACH timing in the frequency domain (e.g., 0 ≤ f_id < 8), and ul_carrier_id can be the UL carrier used for preamble transmission (e.g., 0 for NUL carriers and 1 for SUL carriers).

[0199] The UE may transmit Msg 3 1313 in response to successful reception of Msg 2 1312 (e.g., using the resource identified in Msg 2 1312). Msg 3 1313 can be used for, for example... Figure 13A The diagram illustrates contention resolution in a contention-based random access procedure. In some scenarios, multiple UEs may transmit the same preamble to a base station, and the base station may provide a RAR corresponding to each UE. If these multiple UEs interpret the RAR as corresponding to themselves, a conflict may occur. Contention resolution (e.g., using Msg 3 1313 and Msg 4 1314) can be used to increase the likelihood that a UE will not mistakenly use the identity of another UE. To perform contention resolution, the UE may include a device identifier in Msg 3 1313 (e.g., the TC-RNTI included in Msg 2 1312 if a C-RNTI is assigned, and / or any other suitable identifier).

[0200] Msg 4 1314 can be received after or in response to the transmission of Msg 3 1313. If Msg 3 1313 includes a C-RNTI, the base station will use the C-RNTI to address the UE on the PDCCH. If the UE's unique C-RNTI is detected on the PDCCH, the random access procedure is determined to have been successfully completed. If Msg 3 1313 includes a TC-RNTI (e.g., if the UE is in RRC_IDLE state or not otherwise connected to the base station), Msg 4 1314 will be received using the DL-SCH associated with the TC-RNTI. If the MAC PDU is successfully decoded and the MAC PDU includes a UE contention resolution identity MAC CE that matches or otherwise corresponds to the CCCH SDU transmitted in Msg 3 1313, the UE can determine that contention resolution was successful and the random access procedure was successfully completed.

[0201] The UE can be configured with Supplemental Uplink (SUL) carriers and Normal Uplink (NUL) carriers. Initial access (e.g., random access procedure) can be supported on the uplink carriers. For example, the base station can configure two separate RACH configurations for the UE: one for the SUL carrier and another for the NUL carrier. To enable random access in a cell configured with an SUL carrier, the network can indicate which carrier (NUL or SUL) to use. For example, the UE can determine the SUL carrier if the measured quality of one or more reference signals is below a broadcast threshold. Uplink transmissions during the random access procedure (e.g., Msg 1 1311 and / or Msg 3 1313) can be preserved on the selected carrier. In one or more cases, the UE can switch uplink carriers during the random access procedure (e.g., between Msg 1 1311 and Msg 3 1313). For example, the UE can determine and / or switch uplink carriers for Msg 1 1311 and / or Msg 3 1313 based on channel clarity assessment (e.g., listen before speaking).

[0202] Figure 13B This illustrates a two-step contention-free random access procedure. (Compared to...) Figure 13A Similar to the four-step contention-based random access procedure shown, the base station can transmit configuration message 1320 to the UE before the procedure is initiated. Configuration message 1320 may be similar to configuration message 1310 in some respects. Figure 13B The program shown involves the transmission of two messages: Msg 1 1321 and Msg 2 1322. Msg 1 1321 and Msg 2 1322 can be similar in some respects to... Figure 13A The examples shown are Msg 1 1311 and Msg 2 1312. (As shown from...) Figure 13A and Figure 13B It will be understood that a contention-free random access procedure may not include messages such as Msg3 1313 and / or Msg 4 1314.

[0203] It can be initiated for beam fault recovery, other SI requests, SCell addition and / or handover. Figure 13B The contention-free random access procedure is illustrated. For example, the base station may indicate or assign a preamble to the UE for Msg 1 1321. The UE may receive the preamble indication (e.g., ra-PreambleIndex) from the base station via PDCCH and / or RRC.

[0204] After transmitting the preamble, the UE can initiate a time window (e.g., ra-ResponseWindow) to monitor the PDCCH of the RAR. In the event of a beam failure recovery request, the base station can configure the UE with a separate time window and / or a separate PDCCH within the search space indicated by the RRC message (e.g., recoverySearchSpaceId). The UE can monitor the PDCCH transmission of the Cell RNTI (C-RNTI) addressed to the search space. Figure 13B In the contention-free random access procedure shown, the UE can determine that the random access procedure was successfully completed after or in response to the transmission of Msg 1 1321 and the reception of the corresponding Msg 2 1322. For example, if the PDCCH transmission addresses to the C-RNTI, the UE can determine that the random access procedure was successfully completed. For example, if the UE receives a RAR including a preamble identifier corresponding to the preamble transmitted by the UE and / or the RAR includes a MAC sub-PDU with the preamble identifier, the UE can determine that the random access procedure was successfully completed. The UE can determine that this response is an indication of confirmation of the SI request.

[0205] Figure 13C Another two-step random access procedure is shown. (Compared to...) Figure 13A and Figure 13B Similar to the random access procedure shown, the base station can transmit configuration message 1330 to the UE before the procedure is initiated. Configuration message 1330 may be similar in some respects to configuration message 1310 and / or configuration message 1320. Figure 13C The program shown includes the transmission of two messages: Msg A1331 and Msg B1332.

[0206] Msg A 1331 can be transmitted by the UE in uplink transmission. Msg A 1331 may include one or more transmissions of preamble 1341 and / or one or more transmissions of transport block 1342. Transport block 1342 may include... Figure 13A The content shown in Msg 3 1313 is similar to and / or equivalent to that of Msg 3 1313. Transport block 1342 may include UCIs (e.g., SR, HARQ ACK / NACK, etc.). The UE may receive Msg B 1332 after or in response to the transmission of Msg A 1331. Msg B 1332 may include content similar to and / or equivalent to that shown in Msg 3 1313. Figure 13A and Figure 13B The Msg 2 1312 shown (e.g., RAR) and / or Figure 13A The content shown in Msg 4 1314 is similar to and / or equivalent to the content shown in Msg 4 1314.

[0207] UE can initiate [activities] on licensed spectrum and / or unlicensed spectrum. Figure 13C The two-step random access procedure is used in the UE. The UE may determine whether to initiate a two-step random access procedure based on one or more factors. These one or more factors may be: the radio access technology being used (e.g., LTE, NR, etc.); whether the UE has a valid TA; cell size; the UE's RRC status; the type of spectrum (e.g., licensed vs. unlicensed); and / or any other suitable factors.

[0208] The UE can determine the radio resources and / or uplink transmission power of the preamble 1341 and / or transport block 1342 included in Msg A 1331 based on the two-step RACH parameters included in configuration message 1330. The RACH parameters can indicate the modulation and coding scheme (MCS), time-frequency resources, and / or power control of the preamble 1341 and / or transport block 1342. The time-frequency resources (e.g., PRACH) for the transmission of the preamble 1341 and the time-frequency resources (e.g., PUSCH) for the transmission of the transport block 1342 can be multiplexed using FDM, TDM, and / or CDM. The RACH parameters enable the UE to determine the receive timing and downlink channel for monitoring and / or receiving Msg B 1332.

[0209] Transport block 1342 may include data (e.g., delay-sensitive data), a UE identifier, security information, and / or device information (e.g., International Mobile Subscriber Identity (IMSI)). The base station may transmit Msg B 1332 as a response to Msg A 1331. Msg B 1332 may include at least one of the following: a preamble identifier; a timing advanced command; a power control command; an uplink grant (e.g., radio resource assignment and / or MCS); a UE identifier for contention resolution; and / or an RNTI (e.g., a C-RNTI or a TC-RNTI). The UE can determine that the two-step random access procedure was successfully completed if: the preamble identifier in Msg B 1332 matches the preamble transmitted by the UE; and / or the UE identifier in Msg B 1332 matches the UE identifier in Msg A 1331 (e.g., transport block 1342).

[0210] The UE and the base station can exchange control signaling. The control signaling may be referred to as L1 / L2 control signaling and may originate from the PHY layer (e.g., Layer 1) and / or the MAC layer (e.g., Layer 2). The control signaling may include downlink control signaling transmitted from the base station to the UE and / or uplink control signaling transmitted from the UE to the base station.

[0211] Downlink control signaling may include: downlink scheduling assignment; uplink scheduling grants indicating uplink radio resources and / or transmission formats; time slot format information; preemption indication; power control commands; and / or any other suitable signaling. The UE may receive downlink control signaling in the payload transmitted by the base station on the Physical Downlink Control Channel (PDCCH). The payload transmitted on the PDCCH may be referred to as Downlink Control Information (DCI). In some scenarios, the PDCCH may be a group-shared PDCCH (GC-PDCCH) common to the UE group.

[0212] A base station can attach one or more Cyclic Redundancy Check (CRC) parity bits to the DCI to aid in the detection of transmission errors. When the DCI is intended for use with a UE (or a group of UEs), the base station can scramble the CRC parity bits with the UE's identifier (or the UE group's identifier). Scrambling the CRC parity bits with the identifier can include a Modulo-2 appending (or an exclusive OR operation) of the identifier value and the CRC parity bits. This identifier can include the 16-bit value of the Radio Network Temporary Identifier (RNTI).

[0213] DCIs can be used for various purposes. The purpose can be indicated by the type of RNTI used to scramble the CRC parity bits. For example, a DCI with CRC parity bits scrambled using a paging RNTI (P-RNTI) can indicate paging information and / or system information change notifications. A P-RNTI can be predefined as "FFFE" in hexadecimal. A DCI with CRC parity bits scrambled using a system information RNTI (SI-RNTI) can indicate broadcast transmission of system information. A SI-RNTI can be predefined as "FFFF" in hexadecimal. A DCI with CRC parity bits scrambled using a random access RNTI (RA-RNTI) can indicate a random access response (RAR). A DCI with CRC parity bits scrambled using a cell RNTI (C-RNTI) can indicate dynamically scheduled unicast transmissions and / or triggering of PDCCH ordered random access. A DCI with CRC parity bits scrambled using a temporary cell RNTI (TC-RNTI) can indicate contention resolution (e.g., with...). Figure 13AThe Msg 3 shown is similar to Msg 3 (1313). Other RNTIs configured by the base station for the UE may include: Configured Scheduling RNTI (CS-RNTI), Transmission Power Control PUCCH RNTI (TPC-PUCCH-RNTI), Transmission Power Control PUSCH RNTI (TPC-PUSCH-RNTI), Transmission Power Control SRS RNTI (TPC-SRS-RNTI), Interruption RNTI (INT-RNTI), Slot Format Indication RNTI (SFI-RNTI), Semi-Persistent CSI RNTI (SP-CSI-RNTI), Modulation and Coding Scheme Cell RNTI (MCS-C-RNTI), etc.

[0214] Depending on the purpose and / or content of the DCI, the base station may transmit DCI with one or more DCI formats. For example, DCI format 0_0 can be used for PDSCH scheduling in a cell. DCI format 0_0 can be a fallback DCI format (e.g., with a compact DCI payload). DCI format 0_1 ​​can be used for PUSCH scheduling in a cell (e.g., with a larger DCI payload than DCI format 0_0). DCI format 1_0 can be used for PDSCH scheduling in a cell. DCI format 1_0 can be a fallback DCI format (e.g., with a compact DCI payload). DCI format 1_1 can be used for PDSCH scheduling in a cell (e.g., with a larger DCI payload than DCI format 1_0). DCI format 2_0 can be used to provide slot format indication to UE groups. DCI format 2_1 can be used to notify UE groups of physical resource blocks and / or OFDM symbols, where UEs may assume that transmission to UEs is not expected. DCI format 2_2 can be used to transmit Transmission Power Control (TPC) commands for PUCCH or PUSCH. DCI format 2_3 can be used to transmit a set of TPC commands for SRS transmission by one or more UEs. New DCI formats for new features can be defined in future versions. DCI formats can have different DCI sizes, or they can share the same DCI size.

[0215] After scrambling the DCI with RNTI, the base station can process the DCI using channel coding (e.g., polarity coding), rate matching, scrambling, and / or QPSK modulation. The base station can map the coded and modulated DCI onto resource elements used for and / or configured for the PDCCH. Based on the DCI payload size and / or the base station's coverage area, the base station can transmit the DCI via a PDCCH occupying multiple consecutive control channel elements (CCEs). The number of consecutive CCEs (referred to as the aggregation level) can be 1, 2, 4, 8, 16, and / or any other suitable number. CCEs can include the number of resource element groups (REGs) (e.g., 6). REGs can include resource blocks in OFDM symbols. The mapping of the coded and modulated DCI onto resource elements can be based on the mapping between CCEs and REGs (e.g., CCE-to-REG mapping).

[0216] Figure 14A An example of a CORESET configuration for the bandwidth portion is shown. A base station can transmit DCI via PDCCH on one or more control resource sets (CORESETs). A CORESET can include time-frequency resources in which a UE attempts to decode the DCI using one or more search spaces. The base station can configure the CORESET in the time-frequency domain. Figure 14A In the example, the first CORESET 1401 and the second CORESET 1402 appear at the first symbol in the time slot. The first CORESET 1401 overlaps with the second CORESET 1402 in the frequency domain. The third CORESET 1403 appears at the third symbol in the time slot. The fourth CORESET 1404 appears at the seventh symbol in the time slot. CORESETs can have different numbers of resource blocks in the frequency domain.

[0217] Figure 14B An example of CCE-to-REG mapping for DCI transmission is shown in CORESET and PDCCH processing. CCE-to-REG mapping can be interleaved (e.g., for providing frequency diversity) or non-interleaved (e.g., for facilitating interference coordination and / or frequency-selective transmission in the control channel). The base station can perform different or the same CCE-to-REG mappings for different CORESETs. A CORESET can be associated with CCE-to-REG mapping via RRC configuration. A CORESET can be configured with antenna port quasi-co-location (QCL) parameters. Antenna port QCL parameters can indicate the QCL information for the demodulation reference signal (DMRS) used for PDCCH reception in the CORESET.

[0218] The base station can transmit an RRC message to the UE containing configuration parameters for one or more CORESETs and one or more search space sets. The configuration parameters can indicate the association between the search space set and the CORESET. The search space set can include a set of PDCCH candidates formed by CCEs at a given aggregation level. The configuration parameters can indicate: the number of PDCCH candidates to be monitored at each aggregation level; the PDCCH monitoring period and PDCCH monitoring mode; one or more DCI formats to be monitored by the UE; and / or whether the search space set is a common search space set or a UE-specific search space set. The set of CCEs in the common search space set can be predefined and known to the UE. The set of CCEs in the UE-specific search space set can be configured based on the UE's identity (e.g., C-RNTI).

[0219] like Figure 14B As shown, the UE can determine the time-frequency resources of the CORESET based on RRC messages. The UE can determine the CCE-to-REG mapping of the CORESET (e.g., interleaved or non-interleaved and / or mapping parameters) based on the CORESET's configuration parameters. The UE can determine the number of search space sets configured on the CORESET (e.g., up to 10) based on RRC messages. The UE can monitor a set of PDCCH candidates based on the configuration parameters of the search space sets. The UE can monitor a set of PDCCH candidates in one or more CORESETs for detecting one or more DCIs. Monitoring may include decoding one or more PDCCH candidates in the set of PDCCH candidates according to the monitored DCI format. Monitoring may include decoding the DCI content of one or more PDCCH candidates, which have possible (or configured) PDCCH locations, possible (or configured) PDCCH formats (e.g., the number of CCEs, the number of PDCCH candidates in the common search space, and / or the number of PDCCH candidates in the UE-specific search space), and possible (or configured) DCI formats. Decoding may be referred to as blind decoding. The UE can determine that the DCI is valid for the UE in response to a CRC check (e.g., scrambling bits of the CRC parity bit of the DCI that match the RNTI value). The UE can process the information contained in the DCI (e.g., scheduling assignment, uplink grant, power control, slot format indication, downlink preemption, etc.).

[0220] The UE can transmit uplink control signaling (e.g., uplink control information (UCI)) to the base station. Uplink control signaling transmission may include a Hybrid Automatic Repeat Request (HARQ) acknowledgment for a received DL-SCH transport block. The UE may transmit the HARQ acknowledgment after receiving the DL-SCH transport block. Uplink control signaling may include channel state information (CSI) indicating the channel quality of the physical downlink channel. The UE may transmit the CSI to the base station. Based on the received CSI, the base station can determine transmission format parameters (e.g., including multiple antennas and beamforming schemes) for downlink transmission. Uplink control signaling may include a scheduling request (SR). The UE may transmit an SR indicating that uplink data is available for transmission to the base station. The UE may transmit UCI (e.g., HARQ acknowledgment, CSI report, SR, etc.) via the Physical Uplink Control Channel (PUCCH) or the Physical Uplink Shared Channel (PUSCH). The UE may use one of several PUCCH formats to transmit uplink control signaling via the PUCCH.

[0221] Five PUCCH formats can exist, and the UE can determine the PUCCH format based on the size of the UCI (e.g., the number of uplink symbols transmitted for the UCI and the number of UCI bits). PUCCH format 0 can have a length of one or two OFDM symbols and can include two or fewer bits. If more than one or two symbols are transmitted and the number of HARQ-ACK information bits (HARQ-ACK / SR bits) with positive or negative SR is one or two, the radio device can use PUCCH format 0 to transmit the UCI in the PUCCH resource. PUCCH format 1 can occupy between four and fourteen OFDM symbols and can include two or fewer bits. If four or more symbols are transmitted and the number of HARQ-ACK / SR bits is one or two, the UE can use PUCCH format 1. PUCCH format 2 can occupy one or two OFDM symbols and can include more than two bits. If more than one or two symbols are transmitted and the number of UCI bits is two or more, the UE can use PUCCH format 2. PUCCH format 3 can occupy between four and fourteen OFDM symbols and can include more than two bits. If four or more symbols are transmitted, the number of UCI bits is two or more, and the PUCCH resource does not include an orthogonal overlay code, the UE can use PUCCH format 3. PUCCH format 4 can occupy between four and fourteen OFDM symbols and can include more than two bits. If four or more symbols are transmitted, the number of UCI bits is two or more, and the PUCCH resource includes an orthogonal overlay code, the UE can use PUCCH format 4.

[0222] The base station can transmit configuration parameters for multiple PUCCH resource sets to the UE using, for example, an RRC message. These multiple PUCCH resource sets (e.g., up to four sets) can be configured on the cell's uplink BWP. A PUCCH resource set can be configured with: a PUCCH resource set index; multiple PUCCH resources (e.g., pucch-Resourceid) identified by a PUCCH resource identifier; and / or multiple (e.g., a maximum number) UCI ​​information bits that the UE can transmit using one of the multiple PUCCH resources in the PUCCH resource set. When multiple PUCCH resource sets are configured, the UE can select one of the multiple PUCCH resource sets based on the total bit length of the UCI information bits (e.g., HARQ-ACK, SR, and / or CSI). If the total bit length of the UCI information bits is two or fewer, the UE can select a first PUCCH resource set with a PUCCH resource set index equal to "0". If the total length of the UCI information bits is greater than two and less than or equal to the first configuration value, the UE can select a second PUCCH resource set with a PUCCH resource set index equal to "1". If the total length of the UCI information bits is greater than the first configuration value and less than or equal to the second configuration value, the UE can select a third PUCCH resource set with a PUCCH resource set index equal to "2". If the total length of the UCI information bits is greater than the second configuration value and less than or equal to the third value (e.g., 1406), the UE can select a fourth PUCCH resource set with a PUCCH resource set index equal to "3".

[0223] After determining a PUCCH resource set from multiple PUCCH resource sets, the UE can determine the PUCCH resources used for UCI (HARQ-ACK, CSI, and / or SR) transmission from the PUCCH resource set. The UE can determine the PUCCH resources based on the PUCCH resource indicator in the DCI received on the PDCCH (e.g., a DCI with DCI format 1_0 or a DCI for 1_1). The three-bit PUCCH resource indicator in the DCI can indicate one of the eight PUCCH resources in the PUCCH resource set. Based on the PUCCH resource indicator, the UE can use the PUCCH resource indicated by the PUCCH resource indicator in the DCI to transmit UCI (HARQ-ACK, CSI, and / or SR).

[0224] Figure 15 An example of a wireless device 1502 communicating with a base station 1504 according to an embodiment of the present disclosure is shown. The wireless device 1502 and the base station 1504 may be part of a mobile communication network, such as... Figure 1A The mobile communication network 100 shown Figure 1B The mobile communication network 150 shown or any other communication network. Figure 15 The diagram shows only one wireless device 1502 and one base station 1504, but it should be understood that a mobile communication network may include more than one UE and / or more than one base station, which have the same characteristics as... Figure 15 The same or similar configurations shown.

[0225] Base station 1504 can connect wireless device 1502 to the core network (not shown) via radio communication through air interface (or radio interface) 1506. The communication direction from base station 1504 to wireless device 1502 via air interface 1506 is referred to as the downlink, while the communication direction from wireless device 1502 to base station 1504 via air interface 1506 is referred to as the uplink. Downlink transmissions can be separated from uplink transmissions using some combination of FDD, TDD, and / or two duplex technologies.

[0226] In the downlink, data to be transmitted from base station 1504 to wireless device 1502 can be provided to processing system 1508 of base station 1504. This data can be provided to processing system 1508 via, for example, a core network. In the uplink, data to be transmitted from wireless device 1502 to base station 1504 can be provided to processing system 1518 of wireless device 1502. Processing systems 1508 and 1518 can implement Layer 3 and Layer 2 OSI functions to process the data for transmission. Layer 2 may include, for example, information about... Figure 2A , Figure 2B , Figure 3 and Figure 4A The three layers are SDAP, PDCP, RLC, and MAC. These three layers may include, for example, the SDAP layer, PDCP layer, RLC layer, and MAC layer. Figure 2B The RRC layer.

[0227] After being processed by processing system 1508, data to be transmitted to wireless device 1502 can be provided to transmission processing system 1510 of base station 1504. Similarly, after being processed by processing system 1518, data to be transmitted to base station 1504 can be provided to transmission processing system 1520 of wireless device 1502. Transmission processing systems 1510 and 1520 can implement Layer 1 OSI functions. Layer 1 may include information about... Figure 2A , Figure 2B , Figure 3 and Figure 4A The PHY layer. For transmission processing, the PHY layer can perform operations such as forward error correction coding of the transport channel, interleaving, rate matching, mapping of the transport channel to the physical channel, modulation of the physical channel, multiple-input multiple-output (MIMO) or multiple-antenna processing, etc.

[0228] At base station 1504, receiving processing system 1512 can receive uplink transmissions from wireless device 1502. At wireless device 1502, receiving processing system 1522 can receive downlink transmissions from base station 1504. Receiving processing systems 1512 and 1522 can implement Layer 1 OSI functions. Layer 1 may include information about... Figure 2A , Figure 2B , Figure 3 and Figure 4A The PHY layer. For receive processing, the PHY layer can perform tasks such as error detection, forward error correction decoding, deinterleaving, demapping of the transport channel to the physical channel, demodulation of the physical channel, MIMO or multi-antenna processing, etc.

[0229] like Figure 15 As shown, wireless device 1502 and base station 1504 may include multiple antennas. These multiple antennas can be used to perform one or more MIMO or multi-antenna techniques, such as spatial multiplexing (e.g., single-user MIMO or multi-user MIMO), transmit / receive diversity, and / or beamforming. In other examples, wireless device 1502 and / or base station 1504 may have a single antenna.

[0230] Processing systems 1508 and 1518 may be associated with memory 1514 and memory 1524, respectively. Memory 1514 and memory 1524 (e.g., one or more non-transitory computer-readable media) may store computer program instructions or code that can be executed by processing systems 1508 and / or 1518 to perform one or more of the functions discussed in this application. Although Figure 15 Although not shown, the transmission processing system 1510, transmission processing system 1520, receiving processing system 1512 and / or receiving processing system 1522 may be coupled to a memory (e.g., one or more non-transitory computer-readable media) storing computer program instructions or code that can be executed to perform one or more of their respective functions.

[0231] Processing system 1508 and / or processing system 1518 may include one or more controllers and / or one or more processors. The one or more controllers and / or one or more processors may include, for example, a general-purpose processor, a digital signal processor (DSP), a microcontroller, an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) and / or other programmable logic devices, discrete gate and / or transistor logic, discrete hardware components, onboard units, or any combination thereof. Processing system 1508 and / or processing system 1518 may perform at least one of the following: signal encoding / processing, data processing, power control, input / output processing, and / or any other function that enables wireless device 1502 and base station 1504 to operate in a wireless environment.

[0232] Processing system 1508 and / or processing system 1518 may be connected to one or more peripheral devices 1516 and one or more peripheral devices 1526, respectively. The one or more peripheral devices 1516 and 1526 may include software and / or hardware providing features and / or functions, such as speakers, microphones, keyboards, displays, touchpads, power supplies, satellite transceivers, universal serial bus (USB) ports, hands-free headsets, FM radio units, media players, internet browsers, electronic control units (e.g., for motor vehicles), and / or one or more sensors (e.g., accelerometers, gyroscopes, temperature sensors, radar sensors, lidar sensors, ultrasonic sensors, light sensors, cameras, etc.). Processing system 1508 and / or processing system 1518 may receive user input data from the one or more peripheral devices 1516 and / or 1526 and / or provide user output data to the aforementioned one or more peripheral devices. The processing system 1518 in the wireless device 1502 can receive power from a power source and / or can be configured to distribute power to other components in the wireless device 1502. The power source may include one or more power sources, such as a battery, a solar cell, a fuel cell, or any combination thereof. The processing system 1508 and / or the processing system 1518 may be connected to GPS chipset 1517 and GPS chipset 1527, respectively. GPS chipset 1517 and GPS chipset 1527 may be configured to provide geographic location information for the wireless device 1502 and the base station 1504, respectively.

[0233] Figure 16AAn exemplary structure for uplink transmission is shown. The baseband signal representing the physical uplink shared channel can perform one or more functions. One or more functions may include at least one of the following: scrambling; modulating scrambling bits to generate complex-valued symbols; mapping complex-valued modulation symbols onto one or more transport layers; transform precoding to generate complex-valued symbols; precoding of complex-valued symbols; mapping precoded complex-valued symbols to resource elements; generating complex-valued time-domain single-carrier frequency division multiple access (SC-FDMA) or CP-OFDM signals for antenna ports; and so on. In the example, when transform precoding is enabled, an SC-FDMA signal for uplink transmission can be generated. In the example, when transform precoding is not enabled, it can be achieved through... Figure 16A Generate CP-OFDM signals for uplink transmission. These functions are shown as examples, and other mechanisms are expected to be implemented in various implementation schemes.

[0234] Figure 16B An exemplary structure for modulation and upconversion of a baseband signal to a carrier frequency is shown. The baseband signal can be a complex-value SC-FDMA or CP-OFDM baseband signal from the antenna port and / or a complex-value Physical Random Access Channel (PRACH) baseband signal. Filtering can be applied before transmission.

[0235] Figure 16C An exemplary structure for downlink transmission is shown. The baseband signal representing the physical downlink channel can perform one or more functions. These functions may include: scrambling coded bits in a codeword to be transmitted over the physical channel; modulating the scrambled bits to generate complex-valued modulation symbols; mapping the complex-valued modulation symbols onto one or more transport layers; precoding the complex-valued modulation symbols for transmission at the antenna port; mapping the complex-valued modulation symbols for the antenna port to resource elements; generating a complex-valued time-domain OFDM signal for the antenna port; and so on. These functions are shown as examples, and other mechanisms are contemplated for implementation in various embodiments.

[0236] Figure 16D Another exemplary structure for modulation and upconversion of a baseband signal to a carrier frequency is shown. The baseband signal can be a complex-value OFDM baseband signal at the antenna port. Filtering can be applied before transmission.

[0237] A wireless device can receive one or more messages (e.g., RRC messages) from a base station, including configuration parameters for multiple cells (e.g., primary cell, secondary cell). The wireless device can communicate with at least one base station (e.g., two or more base stations in dual connectivity) via these cells. These messages (e.g., as part of the configuration parameters) may include parameters for configuring the wireless device at the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, and RRC layer. For example, the configuration parameters may include parameters for configuring physical layer and MAC layer channels, bearers, etc. For example, the configuration parameters may include parameters indicating the values ​​of timers for the physical layer, MAC layer, RLC layer, PCDP layer, SDAP layer, RRC layer, and / or communication channels.

[0238] A timer can begin running once started and continues running until it stops or expires. If a timer is not running, it can be started, or if it is running, it can be restarted. A timer can be associated with a value (e.g., a timer can start or restart from a certain value, or it can start from zero and expire once it reaches that value). The duration of a timer may not be updated until the timer stops or expires (e.g., due to BWP switching). Timers can be used to measure time periods / windows of a process. When the specification refers to implementations and procedures related to one or more timers, it should be understood that there are multiple ways to implement the one or more timers. For example, it should be understood that one or more of these multiple ways of implementing a timer can be used to measure time periods / windows of a process. For example, a random access response window timer can be used to measure a time window used to receive a random access response. In the example, instead of starting and expiring the random access response window timer, the time difference between two timestamps can be used. When the timer restarts, the measurement process for the time window can be restarted. Other exemplary implementations for restarting the measurement of a time window can be provided.

[0239] For a two-step RA procedure, the wireless device may receive one or more RRC messages from the base station, including two-step RACH configuration parameters 1330. The one or more RRC messages may be broadcast (e.g., via system information broadcast messages), multicast (e.g., via system information broadcast messages), and / or unicast (e.g., via dedicated RRC messages and / or lower-layer control signals such as PDCCH) to the wireless device. The one or more RRC messages may be wireless device-specific messages, dedicated RRC messages transmitted to wireless devices having RRC inactivity 604 or RRC connection 602. The one or more RRC messages may include parameters required for transmitting Msg A 1331. For example, the parameters may indicate at least one of the following: PRACH resource allocation, preamble format, SSB information (e.g., total number of SSBs, downlink resource allocation for SSB transmission, transmission power for SSB transmission), uplink radio resources (time-frequency radio resources, DMRS, MCS, etc.) for transmission of one or more transport blocks, and / or the association between PRACH resource allocation and uplink radio resources (or the association between uplink radio resources and downlink reference signals).

[0240] In a two-step RA procedure UL transmission (e.g., Msg A 1331), the radio device may, for example, transmit to the base station at least one random access preamble (RAP) (e.g., preamble 1341) and / or one or more transport blocks (e.g., transport block 1342). For example, one or more transport blocks may include at least one of data, security information, device information such as IMSI / TMSI, and / or other information. For example, one or more transport blocks may include a radio device identifier (ID) that can be used for contention resolution. In a two-step RA procedure DL transmission, the base station may transmit Msg B 1332 (e.g., a random access response corresponding to Msg A 1331), which may include at least one of the following: a timing advance command indicating a TA value, a power control command, a UL authorization (e.g., radio resource assignment and / or MCS), an identifier for contention resolution, an RNTI (e.g., C-RNTI or TC-RNTI), and / or other information. Msg B 1332 may include at least one of the following: a preamble identifier corresponding to preamble 1341, a positive or negative acknowledgment of receipt of one or more transport blocks 1342, an implicit and / or explicit indication of successful decoding of one or more transport blocks 1342, or a fallback to a non-two-step RA procedure (e.g., Figure 13A Competition-based RA procedures or Figure 13B Instructions for non-competitive RA procedures, and / or any combination thereof.

[0241] The wireless device can initiate a two-step RA procedure. The wireless device can transmit a Msg A including at least one preamble and / or at least one transport block. At least one transport block can include an identifier used by the wireless device for contention resolution. The identifier can be a sequence and / or number generated by the wireless device (e.g., for cases where the base station has not yet assigned a C-RNTI to the wireless device). The wireless device can randomly generate the identifier and / or generate device information (e.g., IMSI / TMSI) based on subscribers and / or recovery identifiers assigned to the wireless device by the base station. For example, the identifier can be extended and / or truncated subscriber and / or device information (e.g., IMSI / TMSI). For example, the identifier is a C-RNTI (e.g., for a wireless device with an RRC connection). The wireless device can indicate the C-RNTI to the base station based on a specific message format that can be predefined. For example, at least one transport block includes a C-RNTI MAC CE (e.g., a 16-bit field indicating the C-RNTI). The wireless device can transmit a C-RNTI MAC CE with LCID in a subheader corresponding to the C-RNTI MAC CE. For example, LCID can be used by a base station to identify (detect, parse, and / or decode) a C-RNTI MAC CE based on a received signal or message (e.g., a MAC PDU) transmitted from a wireless device.

[0242] The wireless device may begin monitoring the downlink control channel corresponding to Msg B, for example, after transmitting Msg A or in response to transmitting Msg A. The control resource set and / or search space used for monitoring the downlink control channel may be indicated and / or configured by messages transmitted by the base station (e.g., broadcast RRC messages and / or wireless device-specific RRC messages). Msg B may be scrambled by a specific RNTI. The wireless device may use an RNTI assigned by the base station (e.g., a C-RNTI) as the specific RNTI. The wireless device may determine a specific RNTI based on at least one of the following: a time resource index (e.g., an index of the first OFDM symbol and / or an index of the first time slot) for the PRACH timing when at least one preamble is transmitted; a frequency resource index (e.g., an index of the first OFDM symbol and / or an index of the first time slot) for the PUSCH timing when at least one transport block is transmitted; a frequency resource index (e.g., an indicator of the uplink carrier (e.g., 0 or 1) for the transmission of Msg A. The wireless device may determine (or consider) successful completion of the two-step RA procedure based on one or more conditions. At least one of the one or more conditions may be that Msg B includes a preamble index (or identifier) ​​matching at least one preamble transmitted by the wireless device to the base station. At least one of the one or more conditions may be that Msg B includes and / or indicates a contention resolution identifier matching an identifier transmitted by the wireless device to the base station for contention resolution. In the example, the wireless device may receive Msg B indicating a retransmission of at least one transport block. For example, a Msg B indicating a retransmission of at least one transport block includes a UL license indicating uplink resources for retransmitting at least one transport block.

[0243] In a two-step RA procedure UL transmission, the wireless device can transmit at least one RAP and one or more TBs to the base station via the cell. The wireless device can, for example, in... Figure 13CAt step 1330, a message is received regarding one or more configuration parameters for UL transmissions in the two-step RA procedure. For example, one or more configuration parameters may indicate at least one of the following: PRACH timing, preamble format, number of SSB transmissions, downlink resources for SSB transmissions, transmission power for SSB transmissions, association between each PRACH timing and each SSB, PUSCH resources (in terms of time, frequency, code / sequence / signature) for one or more TB transmissions, association between each PRACH timing and each PUSCH resource, and / or power control parameters for one or more TB transmissions. Power control parameters for one or more TB transmissions may include at least one of the following: cell and / or UE-specific power adjustment values ​​for determining the received target power, scaling factors for path loss measurements (e.g., inter-cell interference control parameters), reference signal power for determining path loss measurements, power offset with respect to the preamble transmission power, and / or one or more power offsets. For example, a wireless device measures the received signal power (e.g., RSRP) and / or quality (e.g., RSRQ) of one or more SSBs transmitted by a base station. The wireless device may select at least one SSB based on the measurement and determine at least one PRACH timing associated with the at least one SSB and / or at least one PUSCH resource associated with the at least one PRACH timing and / or the at least one SSB (this association may be explicitly configured by a message and / or implicitly configured through a first association between at least one PRACH and at least one PRACH timing and a second association between at least one PRACH timing and at least one PUSCH resource). The wireless device may transmit at least one RAP via at least one PRACH timing and / or at least one TB via at least one PUSCH resource. The wireless device may determine the transmission power of at least one RAP and / or at least one TB based on configuration parameters indicated by a message. For example, the configuration parameters indicate uplink transmission power control parameters, which include at least one of the following: the target power received by the base station, one or more power offsets, power ramp step size, power ramp counter, retransmission counter, path loss reference signal index (or multiple path loss reference signal indices), and path loss reference signal reference power. At least one of the uplink transmission power control parameters may be shared between the uplink transmission power of at least one RAP and the uplink transmission power of at least one TB.For example, sharing at least one uplink power control parameter among the uplink power control parameters can reduce the message size (e.g., compared to the case where at least one uplink power control parameter is repeated for at least one RAP and at least one TB in the message). No single uplink power control parameter can be shared between the uplink power of at least one RAP and the uplink power of at least one TB. The message structure can be flexible, allowing the base station to indicate to the radio device whether at least one uplink power control parameter can be shared between the uplink power of at least one RAP and the uplink power of at least one TB (or which one or more uplink power control parameters can be shared between the uplink power of at least one RAP and the uplink power of at least one TB). For example, the wireless device determines, based on the message structure of the message, whether at least one uplink transmission power control parameter can be shared between the uplink transmission power of at least one RAP and the uplink transmission power of at least one TB (or which one or more uplink transmission power control parameters can be shared between the uplink transmission power of at least one RAP and the uplink transmission power of at least one TB).

[0244] A radio device may generate one or more candidate preambles for use in a two-step RA procedure in one or more ways. For example, a two-step RACH configuration includes RAP generation parameters (e.g., a root sequence), based on which the radio device generates one or more candidate preambles. The radio device may (e.g., randomly) select one of the one or more candidate preambles as the RAP to be used for transmitting preamble 1341. The RAP generation parameters may be DL reference signal (e.g., SSB or CSI-RS) specific, cell specific, and / or radio device specific. For example, the RAP generation parameters for a first DL reference signal may differ from those for a second DL reference signal. For example, the RAP generation parameters may be common to one or more DL reference signals in a cell in which the radio device initiates the two-step RA procedure. For example, the radio device receives control messages (e.g., SIB messages, RRC messages dedicated to the radio device, and / or PDCCH commands for secondary cell addition) from a base station, which indicate one or more preamble indices for one or more RAPs to be used in the radio device's two-step RA procedure. One or more candidate preambles may be grouped into one or more groups. For example, each group is associated with a specific amount of data to be transmitted. For instance, the data amount indicates the size of one or more transport blocks that the wireless device intends to transmit and / or the size of uplink data held in a buffer. Each of the one or more groups may be associated with a range of data sizes. For example, a first group of one or more groups may include RAPs indicating small data transmissions of transport blocks during a two-step RA procedure, while a second group may include RAPs indicating larger data transmissions of transport blocks during a two-step RA procedure, and so on. The base station may transmit an RRC message including one or more thresholds, based on which the wireless device can determine which group of RAPs to select from. For example, the one or more thresholds indicate one or more data sizes for determining one or more groups. Based on the size of uplink data that the wireless device may transmit, the wireless device compares the size of the uplink data with one or more data sizes and determines a specific group from one or more groups. By transmitting a RAP selected from a specific group, the wireless device can indicate to the base station the (e.g., estimated) size of the uplink data that the wireless device will transmit to the base station. An indication of the size of uplink data can be used by the base station to determine the appropriate size of uplink radio resources for (re)transmitting uplink data.

[0245] In a two-step RA procedure, the wireless device may transmit a RAP via a PRACH timing indicated by the two-step RACH configuration. The wireless device may transmit one or more TBs via UL radio resources (e.g., PUSCH) indicated by the two-step RACH configuration. The first transmission of the RAP and the second transmission of one or more TBs may be scheduled in TDM (Time Division Multiplexing), FDM (Frequency Division Multiplexing), CDM (Code Division Multiplexing), and / or any combination thereof. The first transmission of the RAP may overlap temporally (partially or completely) with the second transmission of one or more TBs. The two-step RACH configuration may indicate a portion of the overlap of radio resources between the RAP and one or more TB transmissions (e.g., in the frequency domain and / or in the time domain). The first transmission of the RAP may be TDM without overlapping with the second transmission of one or more TBs at a different frequency (e.g., PRB) or at the same frequency (e.g., PRB). The two-step RACH configuration may indicate one or more UL radio resources associated with one or more RAPs (or RAP groups) and / or PRACH timings. For example, each of one or more downlink reference signals (SSB or CSI-RS) is associated with one or more PRACH timings and / or one or more RAPs. The radio device may determine at least one PRACH timing and / or at least one RAP among the one or more RAPs. For example, the radio device measures the RSRP and / or RSRQ of one or more downlink reference signals and selects a first downlink reference signal from the one or more downlink reference signals. For example, the RSRP of the first downlink reference signal is greater than a threshold (e.g., indicated by a base station via a control message or signal). The radio device may select at least one RAP and / or at least one PRACH timing associated with the first downlink reference signal as the radio resource for preamble 1341. Based on the selection of at least one RAP and / or at least one PRACH timing, the radio device may determine at least one UL radio resource (e.g., a PUSCH timing) in which the radio device transmits one or more TBs as part of a two-step RACH procedure. The wireless device may determine at least one UL radio resource (e.g., PUSCH timing) based on a first downlink reference signal (e.g., where a control message and / or control signal received by the wireless device from a base station indicates an association between one or more UL radio resources (e.g., PUSCH timing) and one or more downlink reference signals).

[0246] One or more UL radio resources can be based on Figure 7 Frame structure and / or Figure 8The OFDM radio architecture is used to indicate this. For example, the time domain resources of one or more UL radio resources are indicated relative to a specific SFN (SFN=0), the number of time slots, the number of OFDM symbols, and / or combinations thereof. For example, the time domain resources of one or more UL radio resources are indicated relative to the number of subcarriers, the number of resource elements, the number of resource blocks, the number of RBGs, the frequency index of the frequency domain radio resources, and / or combinations thereof. For example, one or more UL radio resources may be indicated based on the time offset and / or frequency offset of one or more PRACH timings relative to a selected RAP. UL transmissions may occur, for example, in the same time slot (or subframe) and / or in different time slots, such as in consecutive time slots (or subframes). For example, one or more UL radio resources (e.g., PUSCH timings) may be configured periodically, for example, as periodic resources configured with license type 1 or type 2.

[0247] The PUSCH timing for a two-step RA procedure can be uplink radio resources for the transmission of block 1342 (e.g., payload) associated with the PRACH preamble in the MsgA 1331 of the two-step RA procedure. One or more examples of resource allocation for the PUSCH timing can be (but are not limited to) configuring the PUSCH timing separately from the PRACH timing. For example, the PUSCH timing can be determined based on periodic resources indicated by configured licenses (e.g., configured license type 1 / type 2 and / or SPS). The radio device can further determine the PUSCH timing based on the association between the PRACH and PUSCH used for msgA transmission. For example, the wireless device may receive configuration parameters from the base station indicating at least one of the following: modulation and coding scheme, transport block size, number of FDM-based PUSCH opportunities (FDM-based PUSCH opportunities may include guard bands and / or guard periods (e.g., if present), and FDM-based PUSCH opportunities under the same Msg A PUSCH configuration may be consecutive in the frequency domain), number of PRBs per PUSCH opportunity, number of DMRS symbols / ports / sequences per PUSCH opportunity, number of repetitions for Msg A PUSCH (transport block 1342) transmission, bandwidth of the PRB-level guard band, duration of the guard period, PUSCH mapping type of transport block 1342, periodicity (e.g., Msg A PUSCH configuration period), offset (e.g., in terms of any combination of at least one of symbols, time slots, subframes, and / or SFNs), and time domain resource allocation (e.g., in terms of resources allocated for Msg A PUSCH). In a PUSCH time slot: start symbol, number of symbols per PUSCH opportunity, number of time-domain PUSCH opportunities, and frequency start point.

[0248] One or more examples of resource allocation for PUSCH timing can be (but are not limited to) the base station configuring the relative position of PUSCH timings with respect to PRACH timings (e.g., in time and / or frequency). For example, the time and / or frequency relationship between the PRACH preamble and the PUSCH timing in a PRACH timing can be a single, fixed-specification value. For example, the time and / or frequency relationship between each PRACH preamble and the PUSCH timing in a PRACH timing is a single, fixed-specification value. For example, different preambles in different PRACH timings have different values. For example, the time and / or frequency relationship between the PRACH preamble and the PUSCH timing in a PRACH timing is a single, semi-statically configured value. For example, the time and / or frequency relationship between each PRACH preamble and the PUSCH timing in a PRACH timing is a semi-statically configured value. For example, different preambles in different PRACH timings have different values. For example, any combination of the above examples can be implemented / configured, and the time and frequency relationships do not have to be identical alternatives. For example, the wireless device may receive configuration parameters from the base station indicating at least one of the following: modulation and coding scheme, transport block size, number of FDM-based PUSCH opportunities (FDM-based PUSCH opportunities may include guard bands and / or guard periods (e.g., if present), and FDM-based PUSCH opportunities under the same Msg A PUSCH configuration may be continuous in the frequency domain), number of PRBs per PUSCH opportunity, number of DMRS symbols / ports / sequences per PUSCH opportunity, number of repetitions for Msg A PUSCH (transport block 1342) transmission, bandwidth of the PRB-level guard band, duration of the guard time, PUSCH mapping type of transport block 1342, time offset relative to a reference point (e.g., a specific SFN, the start or end of the associated PRACH opportunity and / or associated PRACH slot) (e.g., a combination of slot level and symbol level indications), number of symbols per PUSCH opportunity, and number of TDM-based PUSCH opportunities.

[0249] For a two-step RA procedure, resource allocation for payload transmission during the PUSCH phase can be predefined and / or configured. For example, the size of resources during the PUSCH phase can be predefined and / or configured. Resources can be contiguous or non-contiguous (e.g., the base station can flexibly configure resources). Resources can be partitioned into multiple resource groups. For example, the size of each resource group within a PUSCH phase can be the same or different (e.g., depending on the configuration of the two-step RA procedure). Each resource group index can be mapped to one or more preamble indices.

[0250] For example, a base station may use one or more parameters to configure the radio device, which indicate the start point of the time and / or frequency of the PUSCH timing, the number of resource groups, and the size of each resource group within the resource groups. The index of each resource group within a resource group may be mapped to a preamble index (e.g., a specific preamble) and / or a specific PPRCH timing. The radio device may determine the location of each resource group within the resource group based at least on the preamble index (e.g., where RO and PUSCH timing are mapped one-to-one) and / or based on the RO index and preamble index (e.g., where multiple ROs are associated with a single PUSCH timing).

[0251] The wireless device may receive configuration parameters from the base station indicating the start point of the PUSCH timing (time / frequency) and / or a set of consecutive basic units of PUSCH resources. The resource units may be of uniform size, and the total number of available basic units may be pre-configured. The wireless device may use one or more resource units for MsgA 1331 transmission, depending on the payload size. The starting resource unit index may be mapped to a preamble index, and the length of the occupied PUSCH resources (as the number of resource units) may be mapped to a preamble index or explicitly indicated (e.g., in UCI).

[0252] The number of resource groups and / or the detailed mapping between preambles, resource groups, and DMRS ports can be predefined and / or semi-statically configured (and / or dynamically indicated by the DCI) to, for example, avoid blind detection from the base station when multiple preambles are mapped to the same resource group.

[0253] For payload transmission via PUSCHC timing in a two-step RA procedure, the wireless device may receive configuration parameters from the base station indicating one or more MCSs and one or more resource sizes for transmitting the payload. The MCS and resource size may be associated with the payload size. For example, the configuration parameters received by the wireless device may indicate one or more combinations (and / or associations) of the payload size, MCS, and resource size. For example, one or more specific modulation types (e.g., pi / 2-BPSK, BPSK, QPSK) may be associated with a smaller payload size. For example, one or more specific modulation types (e.g., QPSK) may be used for a wireless device with a specific RRC state (e.g., RRC idle and / or RRC inactive). For example, the configuration parameters received by the wireless device may indicate the number of PRBs used for payload transmission over the entire UL BWP and / or a portion of the UL BWP (e.g., this may be predefined and / or semi-statically configured by the RRC). The configuration parameters received by the wireless device may indicate one or more repetitions of transport block 1342 (e.g., payload). For example, one or more conditions for enhancing the coverage of the payload transmission (e.g., RSRP of the downlink reference signal, and / or a specific RRC state, and / or the type of wireless device, e.g., fixed, IoT, etc.) can be predefined, semi-statically configured, and / or the number of repetitions can be triggered.

[0254] The wireless device may receive from the base station one or more two-step RA configurations for transmitting block 1342 (e.g., payload). The one or more two-step RA configurations may indicate one or more combinations of payload size, MCS, and / or resource size. The number of one or more two-step RA configurations and one or more parameter values ​​(e.g., payload size, MCS, and / or resource size) of each of the one or more two-step RA configurations may depend on the content of MsgA and / or the RRC status of the wireless device.

[0255] Based on configured two-step RA configuration parameters, the wireless device can transmit MsgA, including at least one preamble, to the base station via PRACH timing and / or transmit block 1342 (e.g., payload) via PUSCH timing. MsgA may include identifiers for contention resolution. For example, the wireless device may construct a MAC header as a msgA payload with multiple bits (e.g., 56 and / or 72 bits). For example, MsgA may include BSR, PHR, RRC messages, connection requests, etc. For example, MsgA may include UCIs. UCIs in MsgA may include at least one of the following, for example, if MsgA includes UCIs: MCS indication, HARQ-ACK / NACT, and / or CSI report. HARQ of MsgA may be combined between the initial transmission of Msg.A and one or more retransmissions of Msg.A PUSCH. For example, Msg.A may indicate the transmission time of MsgA in the PUSCH of MsgA. The size of msgA may vary depending on the use case.

[0256] There may be situations where a radio device receives configuration parameters from a base station indicating different (or independent) PRACH timings between two-step RA and four-step RA procedures. Different (or independent) PRACH timings can reduce receiver uncertainty and / or reduce access latency. The base station can configure the radio device with different (or independent) PRACH resources, allowing the base station to identify whether a received preamble was transmitted by the radio device for a two-step RA or a four-step RA based on the PRACH timing of the received preamble. The base station can flexibly determine whether to configure shared or separate PRACH timings between two-step and four-step RA procedures. The radio device may receive RRC messages and / or DCI from the base station, which are explicit or implicit indications of whether shared or separate PRACH timings are configured between two-step and four-step RA procedures. There may be situations where the base station configures one or more shared PRACH timings between two-step and four-step RA procedures and partitions the preamble for both two-step and four-step RA procedures.

[0257] Figure 17A , Figure 17B and Figure 17C This is an example of radio resource allocation for PRACH resources and one or more associated UL radio resources, based on time offset, frequency offset, and a combination of time offset and frequency offset, respectively. For example, time offsets and / or frequency offsets, provided by RRC messages (as part of the RACH configuration) and / or predefined (e.g., as a mapping table), can be allocated to the PRACH timing of MsgA 1331 and one or more associated UL radio resources (e.g., PUSCH timing). Figure 17AThis is an example of a PRACH timing with UL radio resources (e.g., PUSCH timing) TDM. Figure 17B This is an example of a PRACH timing with UL radio resources (e.g., PUSCH timing) FDM. Figure 17C Examples of PRACH timing for TDM and FDM are related to UL radio resources (e.g., PUSCH timing).

[0258] The wireless device may receive one or more downlink reference signals (e.g., SSB or CSI-RS) from a base station, and each of the one or more downlink reference signals may be associated with one or more RACH resources (e.g., PRACH timings) and / or one or more UL radio resources (e.g., PUSCH timings) provided by a two-step RACH configuration. The wireless device may measure one or more downlink reference signals and may select at least one downlink reference signal from the one or more downlink reference signals based on the measured received signal strength and / or quality (or based on other selection rules). The wireless device may transmit RAP (e.g., preamble 1341) and one or more TBs (e.g., transport block 1342) via the PRACH timing associated with at least one downlink reference signal, and via the UL radio resources (e.g., PUSCH timings) associated with the PRACH timing and / or associated with at least one downlink reference signal.

[0259] In the example, the base station may use the RAP received from the radio device to adjust the UL transmission timing of one or more TBs of radio devices in the cell and / or assist in UL channel estimation for one or more TBs. The portion of the two-step RACH procedure used for UL transmission of one or more TBs may include, for example, the radio device ID, C-RNTI, service request (e.g., buffer status report (BSR)), one or more user packets, and / or other information. For example, a radio device in the RRC Connected 602 state may use the C-RNTI as its identifier (e.g., radio device ID). For example, a radio device in the RRC Inactive 604 state may use the C-RNTI (if available), recovery ID, or short MAC-ID as its identifier. For example, a radio device in the RRC Idle 606 state may use the C-RNTI (if available), recovery ID, short MAC-ID, IMSI (International Mobile Subscriber Identifier), T-IMSI (Temporary IMSI), and / or a random number (e.g., generated by the radio device) as its identifier.

[0260] In a two-step RA procedure, the radio device may receive two separate responses corresponding to Msg A: a first response to the transmission of a RAP (e.g., preamble 1342) and a second response to the transmission of one or more TBs (e.g., transport block 1342). The radio device may monitor the PDCCH (e.g., common search space and / or radio device-specific search space) to detect the first response with a random access RNTI generated based on the time and / or frequency index of the PRACH resources for the radio device's RAP transmission. The radio device may monitor the common search space and / or the radio device-specific search space to detect the second response. The radio device may employ a second RNTI to detect the second response. For example, if configured, the second RNTI is a C-RNTI, a random access RNTI generated based on the time and / or frequency index of the PRACH timing for the radio device's RAP transmission, or an RNTI generated based on the time and / or frequency index (and / or DM-RS ID) of the PUSCH resources for the radio device's transmission of one or more TBs. The radio device-specific search space may be predefined and / or configured by RRC messages received from the base station.

[0261] A wireless device may trigger (and / or initiate) a two-step random access procedure based on one or more conditions (e.g., events). For example, one or more conditions (e.g., events) may be at least one of the following: initial access from RRC idle, RRC connection reconstruction procedure, handover, arrival of DL or UL data during RRC connection 602 when UL synchronization is asynchronous, transition from RRC inactivity 604, beam fault recovery procedure, and / or requests for other system information. For example, a PDCCH command, the wireless device's MAC entity, and / or beam fault indication may initiate the random access procedure.

[0262] A wireless device may initiate a two-step RA procedure under specific conditions, such as depending on the service from which data is transmitted (e.g., latency-sensitive data such as URLLC) and / or radio conditions. For example, if the unit is small (e.g., TA is not required) and / or for fixed wireless devices (e.g., TA updates are not required), a base station may configure one or more wireless devices using a two-step RA procedure. The wireless device may obtain the configuration via one or more RRC messages (e.g., MIB, system information block, multicast and / or unicast RRC signaling) and / or via L1 control signaling (e.g., PDCCH command) used to initiate the two-step RA procedure.

[0263] For example, in a macro coverage area, wireless devices may have stored and / or retained TA values, such as stationary or near-stationary wireless devices, like sensor-type wireless devices. In this case, a two-step RA procedure can be initiated. Base stations with macro coverage can use broadcast and / or dedicated signaling to configure a two-step RA procedure, where one or more wireless devices have stored and / or retained TA values ​​within the coverage area.

[0264] A wireless device in the RRC Connection 602 state can perform a two-step RA procedure. For example, a two-step RA procedure can be initiated when the wireless device performs a handover (e.g., a network-initiated handover), and / or when the wireless device needs or requests UL clearance for the transmission of delay-sensitive data and no physical layer uplink control channel resources are available for transmitting the scheduling request. A wireless device in the RRC Inactivity 604 state can perform a two-step RA procedure, for example, for small data transmission while remaining in the RRC Inactivity 604 state or for resuming a connection. The wireless device can initiate a two-step RA procedure, for example, for initial access, such as establishing a radio link, re-establishing a radio link, handover, establishing UL synchronization, and / or scheduling requests when no UL clearance is available.

[0265] The following description presents one or more examples of RA procedures. The procedures and / or parameters described below may not be limited to a specific type of RA procedure. The procedures and / or parameters described below can be applied to four-step RA procedures and / or two-step RA procedures. For example, in the following description, an RA procedure may refer to a four-step RA procedure and / or a two-step RA procedure.

[0266] The wireless device can perform cell search. For example, the wireless device can acquire time and frequency synchronization with the cell and detect the first physical layer cell ID of the cell during the cell search procedure. The wireless device can perform cell search, for example, after the wireless device has received one or more synchronization signals (SS) (e.g., primary synchronization signal (PSS) and secondary synchronization signal (SSS)). The wireless device can assume that the reception timing of one or more physical broadcast channels (PBCH), PSS, and SSS is in consecutive symbols and, for example, forms an SS / PBCH block (SSB). For example, the wireless device can assume that the SSS, PBCH demodulation reference signal (DM-RS), and PBCH data have the same energy per resource element (EPRE). For example, the wireless device can assume that the ratio of PSSEPRE to SSSEPRE in the SS / PBCH block is a specific value (e.g., 0 dB or 3 dB). For example, a wireless device can determine that the ratio of PDCCH DM-RSEPRE to SSS EPRE is within a specific range (e.g., from -8dB to 8dB), for example, when the wireless device has not yet been provided with dedicated higher-layer parameters (e.g., semi-statically configured by RRC messages).

[0267] The wireless device can determine the first symbol index of one or more candidate SS / PBCH blocks. For example, for a half-frame with SS / PBCH blocks, the first symbol index of one or more candidate SS / PBCH blocks can be determined based on the subcarrier spacing of the SS / PBCH blocks. For example, index 0 corresponds to the first symbol of the first time slot in the half-frame. As an example, for a 15 kHz subcarrier spacing, the first symbol of one or more candidate SS / PBCH blocks can have an index {2,8}+14·n, where, for example, for carrier frequencies less than or equal to 3 GHz, n = 0,1, and for example, for carrier frequencies greater than 3 GHz and less than or equal to 6 GHz, n = 0,1,2,3. One or more candidate SS / PBCH blocks in a half-frame can be indexed in ascending time order, for example, from 0 to L-1. The wireless device can determine some bits of the SS / PBCH block index for each half-frame from, for example, a one-to-one mapping with one or more indices of the DM-RS sequence transmitted in the PBCH (e.g., 2 least significant bits (LSBs) for L = 4, or 3 LSB bits for L > 4).

[0268] Before initiating a random access procedure, the base station may transmit one or more RRC messages to configure the radio device, for example, with one or more parameters configured using RACH for a four-step RA procedure, a two-step RA procedure, and / or both a four-step RA procedure and a two-step RA procedure. The one or more RRC messages may be broadcast or multicast to one or more radio devices. The one or more RRC messages may be radio device-specific messages, dedicated RRC messages transmitted to radio devices with RRC inactivity 1520 or RRC connection 1530. The one or more RRC messages may include one or more parameters required for transmitting at least one preamble via one or more random access resources. For example, the one or more parameters may indicate at least one of the following: PRACH resource allocation (e.g., resource allocation for one or more PRACH timings), preamble format, SSB information (e.g., total number of SSBs, downlink resource allocation for SSB transmission, transmission power for SSB transmission, SSB index corresponding to the beam transmitting one or more RRC messages and / or other information), and / or uplink radio resources for one or more transport blocks.

[0269] The base station may further transmit one or more downlink reference signals. For example, the one or more downlink reference signals may include one or more discovery reference signals. The radio device may select a first downlink reference signal from the one or more downlink reference signals. For example, the first downlink reference signal may include one or more synchronization signals and a physical broadcast channel (SS / PBCH). For example, the radio device may adjust downlink synchronization based on one or more synchronization signals. For example, the one or more downlink reference signals may include one or more channel state information reference signals (CSI-RS).

[0270] One or more RRC messages may also include one or more parameters indicating one or more downlink control channels (e.g., PDDCH). Each of the one or more downlink control channels may be associated with at least one of one or more downlink reference signals. For example, a first downlink reference signal may include one or more system information (e.g., Master Information Block (MIB) and / or System Information Block (SIB)). The base station may transmit messages including one or more system information, for example, on the Physical Broadcast Channel (PBCH), Physical Downlink Control Channel (PDCCH), and / or Physical Downlink Shared Channel (PDSCH).

[0271] One or more system information may include at least one information element (e.g., PDCCH-Config, PDCCH-ConfigSIB1, PDCCH-ConfigCommon, and / or any combination thereof). At least one information element may be transmitted from the base station, for example, to indicate one or more control parameters to the radio device. One or more control parameters may indicate one or more control resource sets (CORESETs). For example, one or more control parameters may include parameters indicating a first common CORESET#0 (e.g., controlResourceSetZero) and / or a second common CORESET (e.g., commonControlResourceSet). One or more control parameters may also include one or more search space sets. For example, one or more control parameters may include parameters indicating a first search space (e.g., searchSpaceSIB1) and / or a first common search space #0 (e.g., searchSpaceZero) and / or a first random access search space (e.g., ra-SearchSpace) and / or a first paging search space (e.g., pagingSearchSpace) of the system information block. The radio device may use one or more control parameters to acquire, configure, and / or monitor one or more downlink control channels.

[0272] A radio device can monitor a set of one or more candidates for one or more downlink control channels within one or more control resource sets. The one or more control resource sets may be defined in a first active downlink frequency band (e.g., an active bandwidth portion (BWP)) on a first active serving cell. For example, the first active serving cell is configured by the network to a radio device having one or more search space sets. For example, the radio device decodes each of the one or more downlink control channels in the candidate set of one or more downlink control channels according to a first format of first downlink control information (DCI). The candidate set of one or more downlink control channels may be defined based on one or more search space sets. For example, the one or more search space sets are one or more common search space sets (e.g., type 0-PDCCH, type 0A-PDCCH, type 1-PDCCH, type 2-PDCCH, and / or type 3-PDCCH), one or more radio device-specific search space sets, and / or any combination thereof.

[0273] For example, a wireless device may monitor a candidate set of one or more downlink control channels within a Type 0-PDCCH common search space set. For example, the Type 0-PDCCH common search space set may be configured by at least one information element (e.g., PDCCH-ConfigSIB1 in the MIB). For example, the Type 0-PDCCH common search space set may be configured by one or more search space sets (e.g., searchSpaceSIB1 in PDCCH-ConfigCommon, or searchSpaceZero in PDCCH-ConfigCommon). For example, the Type 0-PDCCH common search space set may be configured for a first format of first downlink control information scrambled with a specific radio network temporary identifier (e.g., System Information-Radio Network Temporary Identifier (SI-RNTI)).

[0274] For example, a wireless device may monitor a candidate set of one or more downlink control channels within a Type 1-PDCCH common search space set. For example, the Type 1-PDCCH common search space set may be configured by one or more search space sets (e.g., ra-searchSpace in PDCCH-ConfigCommon). For example, the Type 1-PDCCH common search space set may be configured for a second format of second downlink control information scrambled by a second radio network temporary identifier (e.g., Random Access-Radio Network Temporary Identifier (RA-RNTI), Temporary Cell-Radio Network Temporary Identifier (TC-RNTI), C-RNTI, and / or an RNTI generated by the wireless device based on a two-step RA procedure, such as MsgB-RNTI).

[0275] A radio device may, for example, determine during cell search the existence of a first control resource set for a first common search space (e.g., type 0-PDCCH). The first control resource set may include one or more resource blocks and one or more symbols. One or more RRC messages may include one or more parameters indicating one or more monitoring opportunities for one or more downlink control channels. For example, the radio device determines the number of consecutive resource blocks and the number of consecutive symbols for the first control resource set of the first common search space. For example, one or more bits (e.g., four most significant bits) of at least one information element (e.g., PDCCH-ConfigSIB1) indicate the number of consecutive resource blocks and the number of consecutive symbols. The radio device may determine one or more monitoring opportunities for one or more downlink control channels from one or more bits (e.g., four least significant bits) of at least one information element (e.g., PDCCH-ConfigSIB1). For example, one or more monitoring opportunities for one or more downlink control channels associated with a first downlink reference signal (e.g., SSB or CSI-RS) are determined based on one or more system frame numbers and one or more time slot indices of the first control resource set. For example, the first downlink reference signal with a first index overlaps in time with the first frame number and the first time slot index.

[0276] A wireless device may select (or determine) a specific downlink channel from one or more downlink control channels based on a first downlink reference signal (e.g., SSB or CSI-RS). For example, the wireless device receives a message indicating the association between one or more downlink control channels and one or more downlink reference signals. The wireless device may select the first downlink reference signal (e.g., SSB or CSI-RS) from one or more downlink reference signals, for example, based on the RSRP of the first downlink reference signal greater than a first value. Based on the association, the wireless device determines the specific downlink channel associated with the first downlink reference signal. The wireless device may determine that the demodulation reference signal antenna port associated with the reception of the first downlink channel is quasi-co-located (QCL) with the first downlink reference signal. For example, the demodulation reference signal antenna port associated with the reception of the first downlink channel and the first downlink reference signal (e.g., corresponding SS / PBCH block) may be quasi-co-located with respect to at least one of the following: average gain, QCL-type A, and / or QCL-type D.

[0277] The wireless device may receive one or more RRC messages from the base station, including one or more random access parameters. For example, one or more RRC messages may include a common (or generic) random access configuration message (e.g., RACH-ConfigCommon and / or RACH-ConfigGeneric) indicating at least one of the following: the total number of random access preambles (e.g., totalNumberOfRA-Preambles), one or more PRACH configuration indices (e.g., prach-ConfigurationIndex), the number of PRACH opportunities that can be multiplexed in the frequency domain (FDM) in a time instance (e.g., msg1-FDM), and the offset of the lowest PRACH opportunity in the frequency domain relative to the first resource block (e.g., msg1-FrequencySt). The parameters include: the power ramp step size of the PRACH (e.g., powerRampingStep), the target power level at the network receiver side (preambleReceivedTargetPower), the maximum number of random access preamble transmissions that can be performed (e.g., preambleTransMax), the window length of the random access response (i.e., RAR, e.g., Msg2) (e.g., ra-ResponseWindow), the number of SSBs per random access channel (RACH) timing, and the number of contention-based preambles per SSB (e.g., ssb-perRACH-OccasionAndCB-PreamblesPerSSB). For example, the total number of random access preambles can be a multiple of the number of SSBs per RACH timing. For example, the window length of the RAR can be the number of time slots. For example, a dedicated random access configuration message (e.g., RACH-ConfigDedicated) can include one or more RACH timings (e.g., timings) for contention-free random access and one or more PRACH mask indices (e.g., ra-ssb-OccasionMaskIndex) for random access resource selection.

[0278] One or more random access parameters (e.g., ssb-perRACH-OccasionAndCB-PreamblesPerSSB) may indicate a first number (e.g., N) of one or more downlink reference signals (e.g., SS / PBCH blocks) that may be associated with the first PRACH timing. One or more random access parameters (e.g., ssb-perRACH-OccasionAndCB-PreamblesPerSSB) may indicate a second number (e.g., R) of one or more random access preambles for the first downlink reference signal and for the first PRACH timing. The one or more random access preambles may be contention-based preambles. The first downlink reference signal may be the first SS / PBCH block. For example, the first number (e.g., if N<1) indicates that the first SS / PBCH block can be mapped to at least one (e.g., 1 / N) consecutive valid PRACH timings. For example, the second number (e.g., R) indicates that at least one preamble with a consecutive index associated with the first SS / PBCH block may start from the first preamble index of the first valid PRACH timing.

[0279] For example, one or more PRACH configuration indices (e.g., prach-ConfigurationIndex) may indicate the preamble format, the periodicity of one or more PRACH time resources, the number of one or more PRACH subframes, the number of PRACH slots within one or more PRACH subframes, the number of PRACH start symbols, and / or the number of time-domain PRACH opportunities within a PRACH slot.

[0280] One or more random access parameters may also include associated periods for mapping one or more SS / PBCH blocks to one or more PRACH times. For example, mapping one or more SS / PBCH block indices to one or more PRACH times based on order. Examples of order may be as follows: by ascending order of the index of at least one preamble in a first PRACH time; by ascending order of the index of one or more frequency resources (e.g., for frequency-multiplexed PRACH times); by ascending order of the index of one or more time resources in a first PRACH time slot (e.g., for time-multiplexed PRACH times); and / or by ascending order of the index of PRACH time slots.

[0281] Control commands that initiate RA procedures (e.g., for SCell addition and / or TA update) may include at least one PRACH mask index. At least the PRACH mask index may indicate one or more PRACH timings associated with one or more downlink reference signals (e.g., SSB and / or CSI-RS). Figure 18An example of a PRACH mask index value that can be indicated by a control command is shown. A wireless device can identify one or more PRACH timings for a specific downlink reference signal (e.g., SSB and / or CSI-RS) based on the PRACH mask index value indicated by a control command (e.g., a PDCCH command). The control command (e.g., PDCCH) may include a field indicating a specific SSB (or CSI-RS). For example, Figure 18 The allowed PRACH timings can be mapped (e.g., sequentially) to indices of a specific SSB. The radio device can select a first PRACH timing indicated by a first PRACH mask index value for a specific SSB during a first association period. The first association period can be a first mapping period. The radio device can reset one or more indices of one or more PRACH timings for the first mapping period.

[0282] Wireless devices can receive instructions from base stations Figure 13A and / or Figure 13B Random access procedures and / or Figure 13C The random access procedure in a two-step random access program consists of one or more messages containing random access parameters. For example, one or more messages may be broadcast RRC messages, device-specific RRC messages, and / or combinations thereof. For example, one or more messages may include at least one of a common random access configuration (e.g., RACH-ConfigCommon), a general random access configuration (e.g., RACH-ConfigGeneric), and / or a device-specific random access configuration (e.g., RACH-ConfigDedicated). For example, for a contention-based (four-step and / or two-step) random access procedure, the device receives at least RACH-ConfigCommon and RACH-ConfigGeneric from the base station. For example, for a contention-free (four-step and / or two-step) random access procedure, the device receives at least RACH-ConfigDedicated along with RACH-ConfigCommon and / or RACH-ConfigGeneric from the base station. A random access procedure on the SCell can be initiated by a PDCCH command having a ra-PreambleIndex that is different from a first index (which may be predefined or configured, e.g., 0b000000).

[0283] A wireless device may initiate a random access procedure based at least on parameters configured in at least one of RACH-ConfigCommon, RACH-ConfigGeneric, and RACH-ConfigDedicated. For example, the wireless device may initiate a random access procedure by its MAC entity and / or its RRC, either after receiving a PDCCH command from a base station or in response to receiving a PDCCH command from a base station. The wireless device may be under one or more conditions, based on which one or more random access procedures need to be initiated. For example, there may be an ongoing random access procedure in the MAC entity at any given time. For example, if the wireless device's MAC entity receives a request for a random access procedure while another random access procedure is already in progress in the MAC entity, the wireless device may continue the ongoing procedure or start a new procedure (e.g., in response to an SI request).

[0284] An exemplary random access common configuration (e.g., RACH-ConfigCommon) could be as follows:

[0285]

[0286]

[0287] For example, messagePowerOffsetGroupB indicates the threshold used for preamble selection. The value of messagePowerOffsetGroupB can be in dB. For example, minusinfinity in RACH-ConfigCommon corresponds to infinity. A value of dB0 can correspond to 0 dB, dB5 can correspond to 5 dB, and so on. msg1-SubcarrierSpacing in RACH-ConfigCommon indicates the subcarrier spacing of PRACH. One or more values ​​(e.g., 15 or 30 kHz (<6 GHz), 60 or 120 kHz (>6 GHz)) can be applicable. A Layer 1 parameter corresponding to msg1-SubcarrierSpacing (e.g., 'prach-Msg1SubcarrierSpacing') may exist. For example, if this parameter does not exist, the radio device can apply the SCS derived from prach-ConfigurationIndex in RACH-ConfigGeneric. The base station can use `msg3-transformPrecoding` to indicate to the radio device whether transform precoding is enabled for data transmission (e.g., Msg3 in a four-step RA procedure and / or one or more TB transmissions in a two-step RA procedure). The absence of `msg3-transformPrecoding` indicates that it is disabled. `numberOfRA-PreamblesGroupA` indicates the number of contention-based (CB) preambles for each SSB in group A. This implicitly determines the number of CB preambles available for each SSB in group B. This setting can be consistent with the setting of `ssb-perRACH-OccasionAndCB-PreamblesPerSSB`. `prach-RootSequenceIndex` indicates the PRACH root sequence index. A Layer 1 parameter corresponding to `ssb-perRACH-OccasionAndCB-PreamblePerSSB` (e.g., "PRACHRootSequenceIndex") may exist. The value range may depend on the size of the preamble, e.g., whether the preamble length (L) is L = 839 or L = 139. `ra-ContentionResolutionTimer` indicates the initial value of the contention resolution timer. For example, a value of `ms8` in `RACH-ConfigCommon` indicates 8ms, a value of `ms16` indicates 16ms, and so on. `ra-Msg3SizeGroupA` indicates a transmit block size threshold in bits. For example, when the transmit block size is smaller than `ra-Msg3SizeGroupA`, the wireless device can use a contention-based RA preamble for group A.`rach-ConfigGeneric` can indicate one or more generic RACH parameters in `RACH-ConfigGeneric`. `restrictedSetConfig` can indicate the configuration of an unrestricted set or the configuration of a restricted set of one of two types. `rsrp-ThresholdSSB` can indicate a threshold for SS block selection. For example, a radio device can select SS blocks and corresponding PRACH resources based on SS blocks that meet the threshold for path loss estimation and (re)transmission. `rsrp-ThresholdSSB-SUL` can indicate a threshold for uplink carrier selection. For example, a radio device can select supplementary uplink (SUL) carriers based on this threshold to perform random access. `ssb-perRACH-OccasionAndCB-PreamblesPerSSB` can indicate the number of SSBs per RACH occasion and the number of contention-based preambles for each SSB. One or more Layer 1 parameters (e.g., "SSB-per-rach-occasion" and / or "CB-preambles-per-SSB") corresponding to `ssb-perRACH-OccasionAndCB-PreamblesPerSSB` may exist. For example, the total number of CB preambles in the RACH timing can be given by CB-preambles-per-SSB*max(1, SSB-per-rach-occasion). totalNumberOfRA-Preambles can indicate the total number of preambles used for contention-based and contention-free random access. For example, totalNumberOfRA-Preambles may not include one or more preambles used for other purposes (e.g., for SI requests). For example, if the field is not present, the radio device may use one or more of the 64 preambles for RA.

[0288] An exemplary random access public configuration for RACH-ConfigGeneric can be as follows:

[0289]

[0290]

[0291] For example, msg1-FDM can indicate the number of PRACH transmission opportunities for FDM in a time instance. A Layer 1 parameter (e.g., "prach-FDM") corresponding to msg1-FDM may exist. msg1-FrequencyStart can indicate the offset of the PRACH transmission opportunity (e.g., the lowest PRACH transmission opportunity) in the frequency domain relative to a specific PRB (e.g., PRB 0). The base station can configure the value of msg1-FrequencyStart such that the corresponding RACH resource is within the bandwidth of the UL BWP. A Layer 1 parameter (e.g., "prach-frequency-start") corresponding to msg1-FrequencyStart may exist. powerRampingStep can indicate the power ramp step size of the PRACH. prach-ConfigurationIndex can indicate the PRACH configuration index. For example, radio access technologies (e.g., LTE and / or NR) can predefine one or more PRACH configurations, and prach-ConfigurationIndex can indicate one of the one or more PRACH configurations. A Layer 1 parameter (e.g., "PRACHConfigurationIndex") corresponding to prach-ConfigurationIndex may exist. `preambleReceivedTargetPower` indicates the target power level at the network receiver side. For example, a multiple of a specific value (e.g., in dBm) can be selected. The RACH-ConfigGeneric example above shows an example when a multiple of 2dBm (e.g., -202, -200, -198...) is selected. `preambleTransMax` indicates the number of RA preamble transmissions to be performed before a failure is declared. For example, `preambleTransMax` indicates the maximum number of RA preamble transmissions to be performed before a failure is declared. `ra-ResponseWindow` can indicate the RAR window length in terms of the number of slots (or subframes, microslots, and / or symbols). The base station can configure a value less than or equal to a specific value (e.g., 10ms). This value can be greater than a specific value (e.g., 10ms). `zeroCorrelationZoneConfig` indicates the index of the preamble sequence generation configuration (e.g., N-CS configuration). Radio access technologies (e.g., LTE and / or NR) may predefine one or more preamble sequence generation configurations, and zeroCorrelationZoneConfig may indicate one of the preamble sequence generation configurations. For example, a radio device may determine the cyclic shift of the preamble sequence based on zeroCorrelationZoneConfig.zeroCorrelationZoneConfig can determine the characteristics of a random access preamble (e.g., a zero-correlation zone).

[0292] An exemplary random access-specific configuration (e.g., RACH-ConfigDedicated) could be as follows:

[0293]

[0294]

[0295]

[0296] For example, the CSI-RS is indicated to the radio device by an identifier (e.g., ID) of the CSI-RS resource defined in the measurement object associated with the serving cell. `ra-OccasionList` can indicate one or more RA occasions. For example, when the radio device performs a contention-free random access (CFRA) procedure after selecting a candidate beam identified by the CSI-RS, the radio device may employ one or more RA occasions. `ra-PreambleIndex` can indicate the RA preamble index used in the RA occasion associated with the CSI-RS. `ra-ssb-OccasionMaskIndex` can indicate the PRACH mask index used for the RA resource. The mask may be valid for one or more SSB resources signaled in `ssb-ResourceList`. `rach-ConfigGeneric` can indicate the configuration of the contention-free random access occasion for the CFRA procedure. `ssb-perRACH-Occasion` can indicate the number of SSBs for each RACH occasion. `ra-PreambleIndex` can indicate the preamble index that the radio device can employ when performing CFRA after selecting a candidate beam identified by the SSB. The `ssb` field in `RACH-ConfigDedicated` may indicate the identifier (e.g., ID) of the SSB transmitted by the serving cell. The `cfra` field in `RACH-ConfigDedicated` may indicate one or more parameters for contention-free random access to a given target cell. For example, if the field (e.g., `cfra`) is not present, the radio device may perform contention-based random access. `ra-prioritization` may indicate one or more parameters that apply to a prioritized random access procedure to a given target cell. For example, if the resource field in `CFRA` is set to `ssb`, the field `SSB-CFRA` may exist in `RACH-ConfigDedicated`; otherwise, it may not exist.

[0297] The wireless device may receive one or more RRC messages from the base station indicating at least one of the following:

[0298] The available set of PRACH timings for the transmission of the random access preamble (e.g., prach-ConfigIndex), the initial random access preamble power (e.g., preambleReceivedTargetPower), and the RSRP thresholds (e.g., rsrp-ThresholdSSB) for selecting the SSB and the corresponding random access preamble and / or PRACH timings. For example, if a random access procedure is initiated for beam failure recovery, rsrp-ThresholdSSB can be configured with a beam failure recovery configuration, such as BeamFailureRecoveryConfig. IE), the RSRP threshold (e.g., rsrp-ThresholdCSI-RS, which can be set based on rsrp-ThresholdSSB and an offset value, such as calculated by multiplying rsrp-ThresholdSSB by powerControlOffset) used for selecting CSI-RS and the corresponding random access preamble and / or PRACH timing, the RSRP threshold (e.g., rsrp-ThresholdSSB-SUL) used for selecting between NUL and SUL carriers, and the RSRP threshold to be used when initiating a random access procedure for beam fault recovery. The power offset between resholdSSB and rsrp-ThresholdCSI-RS (e.g., powerControlOffset), the power ramp factor (e.g., powerRampingStep), the power ramp factor in the case of differentiated random access procedures (e.g., powerRampingStepHighPriority), the index of the random access preamble (e.g., ra-PreambleIndex), and the index indicating the PRACH timing associated with the SSB in which the MAC entity can transmit the random access preamble (e.g., ra-ssb-OccasionMaskIndex). Figure 18Examples of ra-ssb-OccasionMaskIndex values ​​are shown, along with the PRACH timing associated with the CSI-RS in which the MAC entity can transmit random access preambles (e.g., ra-OccasionList), the maximum number of random access preamble transmissions (e.g., preambleTransMax), the number of SSBs mapped to each PRACH timing and the number of random access preambles mapped to each SSB (e.g., ssb-perRACH-OccasionAndCB-PreamblesPerSSB), the time window (duration and / or interval) for monitoring RA responses (e.g., ra-ResponseWindow), and / or the contention resolution timer (e.g., ra-ContentionResolutionTimer).

[0299] In the example, the wireless device initiates a beam fault detection and recovery (RA) procedure. For instance, the wireless device receives an RRC message from the base station for use in the beam fault recovery procedure. Based on the beam fault recovery procedure, the wireless device may indicate to the serving base station one or more serving SSBs / CSI-RSs on which the wireless device has detected a beam fault. Beam faults can be detected by counting one or more beam fault instance indications from lower layers to the wireless device's MAC entity. For example, a wireless device receives an RRC message (e.g., including beam failure recovery configuration, such as BeamFailureRecoveryConfig) from a base station, the RRC message indicating at least one of the following: beamFailureInstanceMaxCount for beam failure detection, beamFailureDetectionTimer for beam failure detection, beamFailureRecoveryTimer for beam failure recovery procedure, rsrp-ThresholdSSB for beam failure recovery RSRP threshold, powerRampingStep for beam failure recovery, preambleReceivedTargetPower for beam failure recovery, preambleReceivedTargetPower for beam failure recovery, preambleTransMax for beam failure recovery, a time window (e.g., ra-ResponseWindow) for monitoring the response for beam failure recovery using a contention-free random access preamble, prach-ConfigIndex for beam failure recovery, ra-ssb-OccasionMaskIndex for beam failure recovery, and ra-OccasionList for beam failure recovery.

[0300] The wireless device may adopt (or use or maintain) one or more parameters (or variables) for random access procedures. For example, one or more parameters (or variables) may indicate at least one of the following: PREMBLE_INDEX, PREMBLE_TRANSMISSION_COUNTER, PREMBLE_POWER_RAMPING_COUNTER, PREMBLE_POWER_RAMPING_STEP, PREMBLE_RECEIVED_TARGET_POWER, PREMBLE_BACKOFF, PCMAX, SCALING_FACTOR_BI, and TEMPORARY_C-RNTI.

[0301] The wireless device may perform random access resource selection for selecting one or more preambles and one or more PRACH timings (or resources including time, frequency, and / or code). For example, one or more of the following may be present: a random access procedure can be initiated for beam failure recovery; and / or the beamFailureRecoveryTimer is running or unconfigured; and / or a contention-free random access resource for a beam failure recovery request has been explicitly provided by the RRC for any SSB and / or CSI-RS associated with it; and / or at least one of the SSBs in the candidateBeamRSList with an SS-RSRP higher than rsrp-ThresholdSSB and a CSI-RS in the candidateBeamRSList with a CSI-RSRP higher than rsrp-ThresholdCSI-RS is available. In this scenario, the radio device may select one or more SSBs in the candidateBeamRSList that have a corresponding one or more SS-RSRP value higher than rsrp-ThresholdSSB, or one or more CSI-RSs in the candidateBeamRSList that have a corresponding one or more CSI-RSRP value higher than rsrp-ThresholdCSI-RS. For example, if there is no ra-PreambleIndex associated with at least one CSI-RS, the radio device may select at least one CSI-RS and set PREAMBLE_INDEX to the ra-PreambleIndex corresponding to an SSB in the candidateBeamRSList that is quasi-co-located with at least one CSI-RS selected by the radio device; otherwise, the radio device may set PREAMBLE_INDEX to the ra-PreambleIndex corresponding to an SSB or CSI-RS selected from the set of random access preambles used for beam fault recovery requests.

[0302] The wireless device can receive a ra-PreambleIndex (which can be predefined or configured, such as 0b000000) that is not a specific preamble index via PDCCH or RRC. In this case, the wireless device can set PREAMBLE_INDEX to the ra-PreambleIndex that is signaled.

[0303] There may be one or more situations where contention-free random access resources associated with an SSB have been explicitly provided to the radio device via RRC, and at least one of the associated SSBs with an SS-RSRP higher than rsrp-ThresholdSSB is available. In this case, the radio device may select the associated SSB with an SS-RSRP higher than rsrp-ThresholdSSB. For example, the radio device sets PREAMBLE_INDEX to the ra-PreambleIndex corresponding to the selected SSB.

[0304] There may be one or more situations where contention-free random access resources associated with a CSI-RS have been explicitly provided to the radio device via RRC, and at least one of the associated CSI-RSs with a CSI-RS RSRP higher than rsrp-ThresholdCSI-RS is available. In this case, the radio device may select the associated CSI-RS with a CSI-RS RSRP higher than rsrp-ThresholdCSI-RSC. For example, the radio device sets PREAMBLE_INDEX to the ra-PreambleIndex corresponding to the selected CSI-RS.

[0305] There may be one or more situations where at least one of the SSBs with an SS-RSRP higher than rsrp-ThresholdSSB is available. In this case, for example, the radio device may select an SSB with an SS-RSRP higher than rsrp-ThresholdSSB. For example, if none of the SSBs with an SS-RSRP higher than rsrp-ThresholdSSB are available, the radio device may select any SSB. For example, random access resource selection is performed when retransmitting Msg1 1311, Msg3 1313, MsgA 1331, and / or transport block 1342. The radio device may select a random access preamble from the same group as the random access preamble transmission attempt, which corresponds to the first transmission of Msg1 1311, Msg3 1313, MsgA 1331, and / or transport block 1342. For example, if an association between the random access preamble and the SSB is configured, the radio device randomly selects ra-PreambleIndex from the random access preambles associated with the selected SSB and the selected random access preamble group with equal probability. Conversely, if no association between the random access preamble and the SSB is configured, the radio device randomly selects ra-PreambleIndex from the random access preambles within the selected random access preamble group with equal probability. The radio device can set PREAMBLE_INDEX to the selected ra-PreambleIndex.

[0306] In the example, if an SSB is selected above and the association between the PRACH timing and the SSB is configured, the wireless device determines the next available PRACH timing from the PRACH timing corresponding to the selected SSB, which is allowed by the constraints given by ra-ssb-OccasionMaskIndex (if configured). (For example, the MAC entity of the wireless device may select the PRACH timing corresponding to the selected SSB from among PRACH timings that occur simultaneously but on different subcarriers (e.g., randomly with equal probability); the MAC entity may take into account the possibility of measurement gaps when determining the next available PRACH timing corresponding to the selected SSB).

[0307] In the example, if CSI-RS is selected above and the association between PRACH timing and CSI-RS is configured, the wireless device determines the next available PRACH timing from the PRACH timings in the ra-OccasionList corresponding to the selected CSI-RS (e.g., the MAC entity of the wireless device can randomly select the PRACH timing corresponding to the selected CSI-RS with equal probability from PRACH timings that occur simultaneously but on different subcarriers; the MAC entity can take into account the possibility of measurement gaps when determining the next available PRACH timing corresponding to the selected CSI-RS).

[0308] If a CSI-RS is selected above and there is no contention-free random access resource associated with the selected CSI-RS, the radio device can determine the next available PRACH opportunity corresponding to the SSB in the candidateBeamRSList that is quasi-co-located with the selected CSI-RS from the PRACH opportunity indicated, for example, by ra-ssb-OccasionMaskIndex (if configured) (ra-ssb-OccasionMaskIndex can indicate restrictions on which PRACH opportunities are allowed to be available). (The MAC entity of the radio device can take into account the possibility of measurement gaps when determining the next available PRACH opportunity corresponding to the SSB that is quasi-co-located with the selected CSI-RS.)

[0309] The wireless device can determine the next available PRACH opportunity. For example, the MAC entity of the wireless device selects a PRACH opportunity from among those that occur simultaneously but on different subcarriers (e.g., randomly with equal probability). The MAC entity can determine the next available PRACH opportunity based on (e.g., by taking into account) the possible occurrence of measurement gaps.

[0310] The radio device can perform random access preamble transmission based on the selected PREABLE INDEX and PRACH timing. For example, if a notification of a pause power ramp counter has not yet been received from a lower layer (e.g., the physical layer); and / or if the selected SSB and / or CSI-RS remain unchanged (e.g., the same as the previous random access preamble transmission), the radio device can increment PREMBLE_POWER_RAMPING_COUNTER, for example, by one or to the next value (e.g., the counter step size can be predefined and / or semi-statically configured). For example, the radio device selects a value for DELTA_PREAMBLE that can be predefined and / or semi-statically configured by the base station and sets PREMBLE_RECEIVED_TARGET_POWER to preambleReceivedTargetPower + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER – 1) × PREMBLE_POWER_RAMPING_STEP.

[0311] The MAC entity of the wireless device can instruct the physical layer to use the selected PRACH, the corresponding RA-RNTI (e.g., if available), PREAMBLE_INDEX, and PREAMBLE_RECEIVED_TARGET_POWER to transmit the random access preamble. For example, the wireless device determines the RA-RNTI associated with the timing of the PRACH in which the random access preamble is transmitted. In an example, the RA-RNTI can be determined based on the index of the first OFDM symbol of the specified PRACH, the index of the first time slot of the specified PRACH in the system frame, the index of the specified PRACH in the frequency domain, and / or the uplink carrier indicator. For example, the specified PRACH is the PRACH in which the wireless device transmits the random access preamble. An exemplary RA-RNTI is determined as:

[0312] RA-RNTI=1+s_id+14×t_id+14×80×f_id+14×80×8×ul_carrier_id

[0313] Where s_id can be the index of the first OFDM symbol specifying the PRACH (0 ≤ s_id < 14), t_id can be the index of the first slot specifying the PRACH in the system frame (0 ≤ t_id < 80), f_id can be the index of the PRACH specifying the frequency domain (0 ≤ f_id < 8), and ul_carrier_id (0 for NUL carriers and 1 for SUL carriers, or vice versa) can be the UL carrier used for Msg1 1311 transmission or preamble 1341. In unlicensed bands, RA-RNTI can be further determined based on SFN and / or RAR window size. For example, RA-RNTI can be further determined based on the remainder after dividing SFN by the RAR window size (e.g., the RAR window size modulo SFN). An exemplary RA-RNTI determination in an unlicensed band could be...

[0314] RA-RNTI = 1 + s_id + 14 × t_id + 14 × 80 × f_id + 14 × 80 × 8 × ul_carrier_id × 14 × 80 × 8 × 2 × (SFN modulo RAR window size),

[0315] Here, SFN is the system frame number of the first time slot, and the RAR window size is configured by higher-level parameters, such as ra-ResponseWindow in RACH-ConfigGeneric. For example, depending on the implementation, (SFN modulo RAR window size) can precede any of the components s_id, 14×t_id, 14×80×f_id, and / or 14×80×8×ul_carrier_id in the RA-RNTI calculation formula.

[0316] A radio device transmitting a random access preamble can begin monitoring the downlink control channel in response to a random access response corresponding to the preamble. For a two-step RA procedure, the radio device may begin monitoring the downlink control channel, for example, after or in response to the transmission of a RAP via PRACH, or after or in response to the transmission of one or more TBs via PUSCH. The possibility of measurement gaps may prevent determination of when the radio device begins monitoring the downlink control channel.

[0317] For example, if the radio device performs a contention-free random access procedure in response to a beam failure recovery request, the radio device may initiate a random access window (e.g., ra-ResponseWindow) at the timing of the first downlink control channel (e.g., PDCCH) from the end of a random access preamble transmission (e.g., Msg1 1311 or Msg1 1321 in the case of a four-step RA procedure) or from the end of transmission of one or more TBs (e.g., transport block 1342 in the case of a two-step RA procedure), which is configured with beam management configuration parameters (e.g., BeamFailureRecoveryConfig). While the random access window is running, the radio device may monitor the first downlink control channel of the SpCell in response to a beam failure recovery request identified by a specific RNTI (e.g., RA-RNTI or C-RNTI).

[0318] For example, if the radio device does not perform a contention-free random access procedure in response to a beam failure recovery request, the radio device may initiate a random access window (e.g., ra-ResponseWindow) at the first downlink control channel timing, starting from the end of a random access preamble transmission (e.g., Msg1 1311 or Msg1 1321 for a four-step RA procedure) or from the end of one or more TB transmissions (e.g., transport block 1342 for a two-step RA procedure), configured with random access configuration parameters (e.g., RACH-ConfigCommon). While the random access response window (e.g., ra-ResponseWindow) is running, the radio device may monitor the first downlink control channel timing of the SpCell for random access responses identified by a specific RNTI (e.g., RA-RNTI or C-RNTI).

[0319] The wireless device can receive the PDCCH based on RA-RNTI. The PDCCH can indicate a downlink assignment, based on which the wireless device can receive one or more TBs including a MAC PDU. For example, the MAC PDU includes at least one MAC subPDU with a corresponding subheader that includes a random access preamble identifier (e.g., RAPID) that matches the preamble transmitted by the wireless device to the base station. In this case, the wireless device can determine that the random access response reception was successful. For example, at least one MAC subPDU includes only a random access preamble identifier (e.g., RAPID), for example, for a random access procedure initiated by the wireless device in response to a system information request.

[0320] In the RA procedure, the radio device may receive at least one RAR (e.g., Msg2 1312, Msg2 1322, or MsgB 1332) from the base station as a response to Msg1 1313, Msg1 1321, or MsgA 1331. The radio device may monitor a search space set (e.g., Type 1-PDCCH common search space) for first downlink control information (e.g., DCI format 1_0). The first downlink control information may be scrambled by a specific radio network temporary identifier (e.g., RA-RNTI, C-RNTI, or msgB-RNTI). The first downlink control information may include a downlink assignment indicating the scheduling of a PDSCH including at least one RAR. The radio device may use the downlink assignment to identify parameters required for decoding / detecting the PDSCH. For example, the downlink assignment indicates at least one of the following: time and frequency resource allocation for the PDSCH, the size of the PDSCH, MCS, etc. The radio device may receive a PDSCH including at least one RAR based on these parameters.

[0321] The wireless device can monitor first downlink control information (e.g., DCI format 1_0) during a time window. The time window may be indicated by one or more RRC messages. For example, the time window may begin at a specific symbol of the first control resource set (e.g., the first or last symbol). The wireless device may receive one or more RRC messages from the network or base station, which include one or more parameters required to receive the first downlink control information on the first control resource set. The wireless device may determine the length of the time window based on one or more parameters (e.g., ra-ResponseWindow). The length of the time window may be defined based on the number of time slots, OFDM symbols, and / or any combination thereof. In this case, the length may depend on the duration of the time slots and / or the OFDM symbols that can be determined based on the parameter set. The length of the time window may be defined based on an absolute duration, for example, in milliseconds.

[0322] The wireless device may stop a time window, for example, after or in response to the successful reception of one or more random access responses. For example, the reception of one or more random access responses may be determined to be successful when they include a preamble index (e.g., random access preamble identity: RAPID) corresponding to a preamble transmitted by the wireless device to the base station. For example, RAPID may be associated with a PRACH transmission. One or more random access responses may include uplink grants indicating one or more uplink resources granted to the wireless device. The wireless device may transmit one or more transport blocks (e.g., Msg 3 1313) via one or more uplink resources.

[0323] RARs can be in the form of one or more MAC subPDUs and / or optional padding MAC PDUs. Figure 19A This is an example of RAR. The MAC subheader can be an aligned octet. Each MAC subPDU may include at least one of the following: a MAC subheader with only a backoff indicator; a MAC subheader with only a RAPID (i.e., acknowledgment of the SI request); or a MAC subheader with both a RAPID and a MAC RAR. Figure 19B This is an example of a MAC subheader with a backoff indicator. For instance, a MAC subheader with a backoff indicator includes one or more header fields, such as... Figure 19B The E / T / R / R / BI mentioned above. For example, if the MAC subPDU includes a backoff indicator, the MAC subPDU with the backoff indicator can be placed at the beginning of the MAC PDU. MAC subPDUs with only RAPID and MAC subPDUs with both RAPID and MAC RAR can be placed anywhere after the MAC subPDU with the backoff indicator, and if present, can be placed before padding, such as... Figure 19A The MAC subheader with RAPID may include one or more header fields, such as... Figure 19C The E / T / RAPID is described above. Padding (if present) may be placed at the end of the MAC PDU. The presence and length of padding may be implicit based on the TB size and the size of the MAC subPDU.

[0324] In the example, one or more header fields in the MAC sub-header may indicate the following: The E field may indicate an extension field, which may be a flag indicating whether the MAC subPDU including this MAC sub-header is the last MAC subPDU in the MAC PDU. The E field may be set to "1" to indicate at least one other MAC subPDU following it. The E field may be set to "0" to indicate that the MAC subPDU containing this MAC sub-header is the last MAC subPDU in the MAC PDU; The T field may be a flag indicating whether the MAC sub-header contains a random access preamble ID or a backoff indicator (one or more backoff values ​​may be predefined, and BI may indicate one of the backoff values). The T field may be set to "0" to indicate the presence of a backoff indicator field (BI) in the sub-header. The T field may be set to "1" to indicate the presence of a random access preamble ID field (RAPID) in the sub-header; The R field may indicate a reserved bit that can be set to "0"; The BI field may be a backoff indicator field that identifies overload conditions in the cell. The BI field can be 4 bits in size; the RAPID field can be a random access preamble identifier field that identifies the transmitted random access preamble. For example, if the RAPID in the MAC subheader of the MAC subPDU corresponds to one of the random access preambles configured for the SI request, then the MAC subPDU may not include the MAC RAR.

[0325] One or more MAC RAR formats may exist. At least one of the following MAC RAR formats can be used in a four-step or two-step RA procedure. For example, Figure 20 This is an example of a MAC RAR format. MAC RAR can be like... Figure 20 The depicted fixed size may include at least one of the following fields: an R field indicating a reserved bit set to "0" or "1"; a timing advance command field indicating an index value TA for controlling the amount of timing adjustment; a UL license field indicating the resources to be used on the uplink; and an RNTI field indicating the identity used during random access (e.g., temporary C-RNTI and / or C-RNTI). For example, for a two-step RA procedure, the RAR may include at least one of the following: UE contention resolution identity, RV ID for retransmitting one or more TBs, decoding success or failure indicator for one or more TBs of transmission, and Figure 20 One or more fields as shown.

[0326] There may be situations where the base station could reuse RARs used for two-step and four-step RA procedures within the MAC PDU. The wireless device may not require the RAR length indicator field, and / or the wireless device may determine the boundaries of each RAR in the MAC PDU based on pre-determined RAR size information, for example, if the RARs used for two-step and four-step RA procedures have the same size. Figure 21 This is an exemplary RAR format that can be used in a MAC PDU, thereby reusing the RAR for a two-step RA procedure and the RAR for a four-step RA procedure. Figure 21 The RAR shown can be a fixed size using the same format for two-step and four-step RA procedures. Depending on the type of RA procedure, the wireless device may use (parse, interpret, or determine) different methods. Figure 21 The bit string (e.g., 6 octets) used for the UE contention resolution identity field. For example, a radio device initiating a two-step RA procedure identifies whether contention resolution was successful (e.g., resolved or completed) based on the bit string by comparing the contention resolution identifier with the bit string (e.g., 6 octets) used for the UE contention resolution identity field. For example, a radio device initiating a four-step RA procedure uses (parses, interprets, or determines) the bit string (e.g., 6 octets) differently, except for contention resolution purposes. For example, in this case, the bit string may indicate an additional UL permission for attaching one or more Msg3 1313 transmission opportunities, fill bits, etc.

[0327] In the example, the RAR used for a two-step RA procedure may have a different format, size, and / or fields than the RAR used for a four-step RA procedure. For example, Figure 22A and Figure 22B This is an exemplary RAR format that can be used for two-step RA procedures. For example, if one or more RARs (e.g., RARs for two-step and four-step RA procedures) are multiplexed into a MAC PDU, and the RARs have different formats between the multiplexed RARs (e.g., between two-step RA procedures and / or between two-step and four-step RA procedures), then the RAR may include a field indicating the type of the RAR or the length of the RAR (e.g., such as...). Figure 21 , Figure 22A and Figure 22B The reserved "R" field is shown. Fields indicating the RAR type (or length) may be in subheadings (such as MAC subheadings), in the MAC RAR, or in a separate MAC subPDU within the RAR (e.g., as shown in the image). Figure 19AThe MAC subPDU 1 and / or MAC subPDU 2 may contain another MAC subPDU indicating the RAR type (or length). The RAR may include fields of different types, which may correspond to implicit and / or explicit indicators in the subheader or within the RAR. The wireless device may determine the boundaries of one or more RARs within the MAC PDU based on one or more indicators.

[0328] A random access response window may exist, whereby the radio device can monitor the downlink control channel in response to a random access response transmitted from the base station, as a response to a preamble received from the radio device. For example, the base station may transmit a message including the value of the RAR window. For example, cell-common or radio device-specific random access configuration parameters in the message (e.g., RACH-ConfigGeneric, RACH-ConfigCommon, RACH-ConfigDedicated, or ServingCellConfig) indicate the value of the RAR window (e.g., ra-ResponseWindow). For example, the value of the RAR window may be fixed to, for example, 10 ms or other time values. For example, the value of the RAR window may be defined based on the number of time slots as shown in RACH-ConfigGeneric. The radio device may identify (or determine) the size of the RAR window (e.g., absolute duration and / or length) based on a set of parameters configured for the random access procedure. For example, the parameter set defines one or more system parameters, such as subcarrier spacing, time slot duration, cyclic prefix size, number of OFDM symbols per time slot, number of time slots per frame, number of time slots per subframe, minimum number of physical resource blocks, and / or maximum number of physical resource blocks. For example, one or more system parameters associated with a parameter set can be predefined using different subcarrier spacing, slot duration, and / or cyclic prefix size. For example, a wireless device might identify a subcarrier spacing of 15 kHz, a normal cyclic prefix, 14 symbols per slot, 10 slots per frame, and / or 1 slot per subframe for parameter set μ = 0. For example, a wireless device might identify a subcarrier spacing of 30 kHz, a normal cyclic prefix, 14 symbols per slot, 20 slots per frame, and / or 2 slots per subframe for parameter set μ = 1. For example, a wireless device might identify a subcarrier spacing of 60 kHz, 14 symbols per slot, 40 slots per frame, and / or 4 slots per subframe for parameter set μ = 2 with a normal cyclic prefix. For example, a wireless device might identify a subcarrier spacing of 60 kHz, 12 symbols per slot, 40 slots per frame, and / or 4 slots per subframe for parameter set μ = 2 with an extended cyclic prefix. For example, a wireless device may identify a subcarrier spacing of 120 kHz, a normal cyclic prefix, 14 symbols per time slot, 80 time slots per frame, and / or 8 time slots per subframe for parameter set μ=3. For example, a wireless device may identify a subcarrier spacing of 240 kHz, a normal cyclic prefix, 14 symbols per time slot, 160 time slots per frame, and / or 16 time slots per subframe for parameter set μ=4.

[0329] The wireless device can determine (or identify) the size (e.g., duration or length) of the RAR window based on a configured RAR window value and parameter set. For example, the RAR window has a duration of 20 ms, for instance, if the configured RAR window value is sl20 (e.g., 20 time slots) and the parameter set is μ = 0 (e.g., the time slot duration for μ = 0 is 1 ms). In the example, a specific RAR window value (e.g., ra-ResponseWindow) configured by an RRC message (e.g., broadcast and / or radio-specific unicast) can be associated with a specific parameter set. For example, in RACH-ConfigGeneric, sl10, sl20, sl40, and sl80 can be the values ​​of ra-ResponseWindow for parameter sets μ = 0, μ = 1, μ = 2, and μ = 3, respectively. In the example, the base station configures a specific RAR window value for the wireless device that is independent of the parameter set. In a licensed band, the size (e.g., duration or length) of the RAR window may not be longer than 10 ms (and / or the periodicity of the PRACH timing). In unlicensed bands, the duration (e.g., size or length) of the RAR window can be longer than 10 ms (and / or the periodicity of the PRACH timing).

[0330] The radio device may perform one or more retransmissions of one or more preambles during a random access procedure (e.g., a two-step RA procedure and / or a four-step RA procedure). There may be one or more conditions upon which the radio device determines one or more retransmissions of one or more preambles. For example, the radio device may determine one or more retransmissions of one or more preambles when it determines that the random access response reception was unsuccessful. For example, the radio device may determine that the random access response reception was unsuccessful if at least one random access response including one or more random access preamble identifiers matching the transmitted PREAMBLE_INDEX is not received until the RAR window (e.g., ra-ResponseWindow configured by RRC, such as RACH-ConfigCommon IE) expires. For example, the radio device may determine that the random access response reception was unsuccessful if a PDCCH addressed to C-RNTI is not received on the serving cell where the preamble was transmitted until the RAR window for beam failure recovery procedures (e.g., ra-ResponseWindow configured in BeamFailureRecoveryConfig) expires.

[0331] For example, when the wireless device determines that contention resolution is unsuccessful, the wireless device may determine one or more retransmissions of one or more preambles. For example, the wireless device may determine whether contention resolution was successful based on Msg 3 1313 for a four-step RA procedure and / or MsgB 1332 for a two-step RA procedure.

[0332] For example, the MAC entity of the wireless device may start a contention resolution timer (e.g., ra-ContentionResolutionTimer), and may restart the contention resolution timer (e.g., ra-ContentionResolutionTimer) at each HARQ retransmission in the reference symbol (e.g., the first symbol after the end of Msg3 transmission), for example, after the wireless device transmits Msg3 1313 to the base station. For example, if the wireless device does not receive an indication of contention resolution while the contention resolution timer (e.g., ra-ContentionResolutionTimer) is running, the wireless device may determine that contention resolution was unsuccessful. For example, if an indication of contention resolution is not received until the contention resolution timer (e.g., ra-CentionResolutionTimer) expires, the wireless device may determine that contention resolution was unsuccessful. The wireless device may discard the TEMPRARY_C-RNTI indicated by Msg2 1312 (or Msg B 1332) after the contention resolution timer expires or in response to the expiration of the contention resolution timer (and / or in response to determining that contention resolution was unsuccessful). If the wireless device determines that contention resolution was successful while a contention resolution timer (e.g., ra-ContentionResolutionTimer) is running, the wireless device may stop the contention resolution timer (e.g., ra-ContentionResolutionTimer). The wireless device may determine successful contention resolution based on a PDCCH addressing a C-RNTI (transmitted via Msg1 1211 or MsgA 1331) detected while the contention resolution timer is running. The wireless device may determine successful contention resolution based on receiving a contention resolution identifier that matches a wireless device identifier (transmitted via Msg3 1213 or MsgA 1331) detected while the contention resolution timer is running.

[0333] For a two-step RA procedure, the wireless device may, for example, start a timer (e.g., a RAR window, a MsgB window, or a contention-resolving timer) after transmitting a transport block 1342 including the wireless device's contention-resolving identifier or in response to transmitting that transport block. For example, if at least one MsgB including the contention-resolving identifier transmitted by the wireless device is not received until the timer expires, the wireless device may determine one or more retransmissions of MsgA 1331 (e.g., preamble 1341 and / or transport block 1342). For example, for a two-step RA procedure, the wireless device may fall back to a four-step RA procedure based on explicit and / or implicit indications of MsgB. For example, if the MsgB received by the wireless device includes such an explicit indication and / or the RNTI of the PDCCH used to detect the scheduling of MsgB is a specific RNTI (e.g., RA-RNTI or msgB RNTI), the wireless device may determine to fall back to a four-step RA procedure. The wireless device may transmit Msg3 via a resource indicated by the UL license in MsgB, for example, after determining to fall back to the four-step RA procedure or in response to determining to fall back to the four-step RA procedure. In this case, the wireless device may follow the four-step RA procedure, such as starting a contention resolution timer and / or determining whether contention resolution was successful. While the contention resolution timer (e.g., ra-ContentionResolutionTimer) is running, the wireless device may monitor the PDCCH. The wireless device may restart the contention resolution timer (e.g., ra-ContentionResolutionTimer) at each HARQ retransmission in the first symbol after the Msg3 transmission has ended. For example, if an indication of contention resolution is not received until the contention resolution timer (e.g., ra-CentionResolutionTimer) expires, the wireless device may determine that contention resolution was unsuccessful. The wireless device may discard the TEMPRARY_C-RNTI indicated by Msg2 1312 (or Msg B 1332) after the contention resolution timer expires or in response to the contention resolution timer expiring (and / or in response to determining that contention resolution was unsuccessful). A radio device that determines a retransmission during a four-step RA procedure with a backoff time of two-step RA procedures may perform a retransmission of MsgA 1331. A radio device that determines a retransmission during a four-step RA procedure with a backoff time of two-step RA procedures may perform a retransmission of Msg1 1311. For example, if a notification of a PDCCH transmission from a receiving cell (e.g., SpCell) is received from a lower layer, and the radio device identifies the PDCCH transmission as an indication of contention resolution corresponding to a Msg3 transmission (or MsgB transmission) performed by the radio device, the radio device may stop the contention resolution timer and determine that contention resolution was successful.

[0334] A wireless device may maintain (e.g., increment) a counter step value (e.g., 1) for a counter (e.g., PREAMBLE_TRANSMISSION_COUNTER) that counts the number of preamble transmissions after an unsuccessful reception of a random access response or in response to an unsuccessful reception of a random access response and / or after an unsuccessful contention resolution or in response to an unsuccessful contention resolution. For example, if the number of preamble transmissions can reach a predefined or semi-statically configured value (e.g., if PREAMBLE_TRANSMISSION_COUNTER = preambleTransMax+1, where preambleTransMax is the predefined or semi-statically configured value), the wireless device may determine that the random access procedure has not been successfully completed and / or the MAC entity of the wireless device may indicate a random access problem to upper layers. For example, if the number of preamble transmissions does not reach the predefined or semi-statically configured value (e.g., if PREAMBLE_TRANSMISSION_COUNTER < preambleTransMax+1), the wireless device may determine that the random access procedure is not completed and / or one or more retransmissions of one or more of Msg1 1311, Msg1 1321, or MsgA 1331 may be performed.

[0335] The wireless device may delay a specific time period (e.g., a backoff time) for performing the retransmission of one or more of Msg1 1311, Msg1 1321, or MsgA 1331. For example, when initiating the random access procedure, the wireless device may set the backoff time to 0 ms. The wireless device may, based on the BI field of the MAC subPDU (e.g., Figure 19B the BI field in), set (or update) the backoff time according to PREAMBLE_BACKOFF determined by the value in the BI field. The value (or bit string) in the BI field may indicate a specific backoff time in a predefined or semi-statically configured table. For example, the wireless device may use the predefined or semi-statically configured table to set PREAMBLE_BACKOFF to the value indicated by the BI field of the MAC subPDU. For example, if the wireless device receives a BI indicating index 3 (or 0010 in the bit string), the wireless device may set PREAMBLE_BACKOFF to the value at row index 3 in the predefined or semi-statically configured table. For example, in Figure 19BIn the example format, four bits are allocated to the BI field. In this case, 16 values ​​may exist in the predefined or semi-static configuration table (e.g., each of the 16 values ​​is identified by a specific row index). For example, if the radio device receives one or more RRC messages indicating a scaling factor from the base station, the radio device may set PREAMBLE_BACKOFF to the value indicated by the BI field of the MAC subPDU multiplied by the scaling factor (e.g., SCALING_FACTOR_BI). For example, if a downlink assignment for RA-RNTI has been received on the PDCCH and the received TB has been successfully decoded, and / or if the random access response includes a backoff indicator (e.g., ... Figure 19B If the BI field in the MAC subPDU is not received, the radio device can set (or update) PREMABLE_BACKOFF based on the BI field. For example, if a downlink assignment for RA-RNTI has not been received on the PDCCH and / or the received TB has not been successfully decoded, and / or if the random access response does not include a backoff indicator (e.g., ... Figure 19B If the MACsubPDU in the BI field is used, the wireless device can set PREAMBLE_BACKOFF to 0ms.

[0336] For example, if the wireless device determines that the random access response is unsuccessful and / or contention resolution is unsuccessful, the wireless device can determine a backoff time. The wireless device can employ a specific selection mechanism to determine the backoff time. For example, the wireless device can determine the backoff time based on a uniform distribution between 0 and PREAMBLE_BACKOFF. The wireless device can use any type of distribution to select the backoff time based on PREAMBLE_BACKOFF. The wireless device can ignore PREAMBLE_BACKOFF (e.g., Figure 19B The value in the BI field of the random access procedure (or the value in the BI field) and / or there may be no backoff time. For example, the wireless device may determine whether to apply backoff time to the retransmission of at least one preamble based on the type of event that initiated the random access procedure (e.g., beam fault recovery request, handover, etc.) and / or the type of random access procedure (e.g., four-step or two-step RA and / or CBRA or CFRA). For example, if the random access procedure is CBRA (e.g., where the preamble is selected by the MAC entity of the wireless device) and / or if the wireless device determines that the random access procedure is not completed based on the unsuccessful reception of the random access response, the wireless device may apply backoff time to the retransmission. For example, if the wireless device determines that the random access procedure is not completed based on the unsuccessful contention resolution, the wireless device may apply backoff time to the retransmission.

[0337] For example, if the random access procedure is not completed, the radio device may perform a random access resource selection procedure (e.g., selecting at least one SSB or CSI-RS and / or selecting a PRACH corresponding to at least one SSB or CSI-RS selected by the radio device). The radio device may delay the subsequent random access preamble transmission by a backoff time (e.g., or delay the execution of the random access resource selection procedure).

[0338] Radio access technologies allow a wireless device to change (switch) channels (uplink carrier, BWP, and / or subband) to transmit at least one preamble for retransmission. This increases the number of preamble transmission opportunities in an unlicensed band. For example, a base station may transmit one or more messages (broadcast messages and / or RRC messages) to the wireless device indicating the configuration of one or more channels (e.g., uplink carrier, BWP, and / or subband) configured with one or more PRACHs. The wireless device may select one of the one or more channels (e.g., BWP and / or subband) as the channel (e.g., uplink carrier, BWP, and / or subband) for transmitting at least one first preamble. The wireless device may select a channel (e.g., uplink carrier, BWP, and / or subband) based on LBT results. For example, the wireless device performs one or more LBTs on one or more channels and selects a channel from those sensed as idle. The wireless device may select a channel from those sensed as idle based on, for example, random selection. There may be situations where switching channels for retransmission is not permitted (e.g., this indication may be predefined or semi-statically communicated).

[0339] The wireless device can determine the transmission power for retransmission of at least one preamble (or MsgA) based on PREMBLE_POWER_RAMPING_COUNTER. For example, the wireless device can set PREMBLE_POWER_RAMPING_COUNTER to an initial value (e.g., 1) as random access procedure initialization. For example, for each random access preamble and / or for each transmission of at least one preamble transmitted, for example after determining that random access reception failed and / or contention resolution failed, or in response to determining that random access reception failed and / or contention resolution failed, the MAC entity of the wireless device can increment PREMBLE_POWER_RAMPING_COUNTER by a counter step size predefined or semi-statically configured by the base station. For example, if PREAMBLE_TRANSMISSION_COUNTER is greater than one; if a notification of a pause power ramp counter has not yet been received from a lower layer (e.g., in response to abandoning preamble transmission due to LBT failure and / or in response to a spatial filter change); and / or if the selected SSB or CSI-RS has not been changed from the selection in the last random access preamble transmission, the MAC entity of the radio device may increment PREAMBLE_POWER_RAMPING_COUNTER by 1. The radio device may determine the value of DELTA_PREAMBLE based on the preamble format and / or parameter set selected for the random access procedure (e.g., one or more values ​​of DELTA_PREAMBLE are predefined and associated with one or more preamble formats and / or parameter sets. For a given preamble format and parameter set, the radio device may select a specific value of DELTA_PREAMBLE from one or more values). The wireless device can determine PREAMBLE_RECEIVED_TARGET_POWER as preambleReceivedTargetPower + DELTA_PREAMBLE + (PREAMBLE_POWER_RAMPING_COUNTER – 1) × PREAMBLE_POWER_RAMPING_STEP. The MAC layer of the wireless device can instruct the physical layer to transmit the random access preamble based on the selected PRACH timing, the corresponding RA-RNTI (e.g., if available), PREAMBLE_INDEX, and / or PREAMBLE_RECEIVED_TARGET_POWER.

[0340] For a two-step RA procedure, MsgA (or transport block) may include a Common Control Channel (CCCH) SDU. For example, the transport block is transmitted for the CCCH logical channel. For example, the radio device may transmit an RRC (re)establishment request, an RRC setup request, and / or an RRC recovery request to the base station via the CCCH. The radio device may begin monitoring a downlink control channel (e.g., PDCCH) with a first RNTI (e.g., msgBRNTI). The PDCCH received via the downlink control channel indicates a downlink assignment including a PDSCH (e.g., MAC PDU) containing MsgB. In this case, the MsgB (or the PDSCH (e.g., MAC PDU) received by the radio device based on the downlink assignment may include a Signaling Radio Bearer (SRB) RRC message. The SRB RRC message may include RRC (re)establishment, RRC setup, and / or RRC recovery, respectively, as a response to the RRC (re)establishment request, RRC setup request, and / or RRC recovery request transmitted by the radio device via MsgA (or transport block).

[0341] When the MsgA (or transport block) includes a Common Control Channel (CCCH) SDU, the MAC PDU (or PDSCH) may multiplex one or more MsgBs for one or more radio devices. The MAC PDU may multiplex one or more MsgBs indicating only the success of MsgA. The MAC PDU may multiplex one or more MsgBs indicating only the failure of MsgA (e.g., a fallback response). The MAC PDU may multiplex multiple MsgBs, including one or more responses indicating the success of MsgA and / or one or more responses indicating the failure of MsgA (e.g., a fallback RAR). The MAC PDU may include at least one backoff indication. For a MsgB indicating the success of MsgA, the MsgB may include at least one of the following: a contention resolution identifier (which matches the identifier transmitted by the radio device via MsgA), a C-RNTI, and / or a TA command. For a MsgB indicating a failure of MsgA (e.g., fallback RAR), MsgB may include at least one of the following: RAPID, UL permission (e.g., for retransmission of the MsgA payload), TC-RNTI, and / or TA command. For example, upon receiving a MsgB indicating a failure of MsgA (e.g., fallback RAR), the wireless device may proceed to a four-step RACH procedure for Msg3 transmission (e.g., in...). Figure 13A (In the context of the text). For example, Msg3 transmitted by the wireless device as part of a fallback procedure includes a CCCH SDU transmitted via MsgA. A MAC PDU including MsgB indicating the success of MsgA may not be multiplexed with a four-step RACH RAR (e.g., Msg 2).

[0342] For a two-step RA procedure, the wireless device can determine whether contention resolution was successful and / or whether Msg B was successfully received, at least based on the C-RNTI. For example, if present, the wireless device can transmit MsgA, including the C-RNTI (e.g., C-RNTI MACCE), to the base station. For example, the wireless device receives a message including the C-RNTI from the base station before or after transmitting MsgA. MsgA (or a block of MsgA) may include a C-RNTI MACCE indicating the C-RNTI. The wireless device can, for example, begin monitoring the downlink control channel (e.g., Msg B) corresponding to MsgA with one or more RNTIs after transmitting MsgA (or a block of MsgA) or in response to transmitting MsgA (or a block of MsgA). For example, the wireless device can monitor the downlink control channel (e.g., PDCCH) with one or more RNTIs after transmitting MsgA indicating the C-RNTI (e.g., C-RNTI MACCE) or in response to transmitting MsgA. One or more RNTIs include a C-RNTI. One or more RNTIs include a first RNTI (e.g., msgB-RNTI), which may be determined (or calculated) based on uplink radio resources used for Msg A transmission. For example, the first RNTI is an RA-RNTI. For example, the first RNTI is determined based on uplink radio resources used for preamble and / or transport block. For example, uplink radio resources include the time (e.g., any combination of OFDM symbols, number of slots, number of subframes, and / or SFN) and / or frequency index of the PRACH timing (for preamble transmission), the preamble identifier of the preamble, the time (e.g., any combination of OFDM symbols, number of slots, number of subframes, SFN, and / or time offset relative to the associated PRACH timing) and / or frequency index of the PUSCH timing (for transport block transmission) and / or DMRS index (e.g., DMRS port identifier). For example, the wireless device may monitor the PDCCH of the C-RNTI for a successful response to MsgA, and monitor the PDCCH of the first RNTI (e.g., msgB-RNTI) for a failed (or fallback) response to MsgA. The wireless device may start a timer (e.g., a contention-resolved timer) and / or monitor the downlink control channel while the timer is running. For example, the timer may determine how long (e.g., a specific time interval or period) the wireless device monitors the downlink control channel to receive a MsgB (e.g., a successful response and / or fallback response) corresponding to MsgA from the base station after or in response to the transmission of MsgA.For example, if the wireless device receives at least one response (e.g., a PDCCH addressed to a C-RNTI and / or a PDCCH addressed to a first RNTI or RA-RNTI), the wireless device may stop monitoring the downlink channel. The wireless device may determine that contention resolution was successful based on one or more conditions. For example, if a PDCCH addressed to a C-RNTI (i.e., a C-RNTI included in MsgA) and / or a PDSCH indicated by a PDCCH (e.g., a downlink assignment in DCI) is successfully decoded, the wireless device determines that contention resolution was successful. The PDSCH may include at least one of a TA command (e.g., a MAC CE including one or more bits indicating a timing advance command) and / or a UL license. The wireless device may stop monitoring the PDCCH, for example, after determining that contention resolution was successful or in response to determining that contention resolution was successful. Detecting a PDCCH addressed to a C-RNTI may be an indication of a successful response (e.g., MsgB). Detecting a PDCCH addressed to a C-RNTI and / or decoding a PDSCH indicated by a PDCCH (e.g., a downlink assignment of the DCI of the PDCCH) can be an indication of a successful response (e.g., MsgB). For example, if the radio device receives a fallback response (e.g., RAR), the radio device stops monitoring PDCCHs addressed to a C-RNTI. In this case, contention resolution is unsuccessful, and the radio device can fall back to the four-step RA procedure for Msg3 transmission. The radio device can identify the fallback response based on a PDCCH addressed to a first RNTI (e.g., msgB RNTI or RA-RNTI). For example, when the radio device monitors a PDCCH, it detects a PDCCH addressed to a first RNTI (e.g., msgB RNTI or RA-RNTI). The PDCCH addressed to the first RNTI may include a downlink assignment, based on which the radio device receives a PDSCH including a fallback response. The PDSCH including the fallback response may include one or more responses. The wireless device identifies a corresponding response (e.g., a success response, a fallback response, and / or MsgB) from one or more responses based on one or more identifiers. For example, if the identifier indicated by the corresponding response matches the preamble index of the preamble transmitted by the wireless device, the wireless device represents the corresponding response from one or more responses. The corresponding response may include fields that implicitly or explicitly indicate whether the corresponding response is a success response or a fallback response. The corresponding response may include a UL license indicating uplink radio resources for Msg3 transmitted based on fallback operation. Figure 19A (For example, with) Figure 19B and Figure 19C This is an exemplary format of the PDU based on the PDSCH received by the first RNTI. For example, Figure 19C In this context, RAPID is the response that the wireless device uses to identify the corresponding fallback response (e.g., ...). Figure 19A An example identifier for the MAC RAR in the context of the device. For example, if neither a backoff response nor a C-RNTI addressed by the PDCCH is detected within a timer (e.g., a contention-resolved timer), the wireless device may determine that MsgB reception (or contention-resolved or MsgA transmission attempt) has failed. In this case, for example, if received in MsgB, the wireless device may base its decision on a backoff indicator (e.g., a backoff indicator). Figure 19B To perform a retreat operation.

[0343] Figure 23This is an example diagram illustrating a two-step RA procedure. A wireless device can receive a message including a C-RNTI from a base station. A wireless device with a C-RNTI can transmit the C-RNTI (e.g., a C-RNTI MAC CE indicating the C-RNTI) to the base station via MsgA during the two-step RA procedure. For example, during the two-step RA procedure, the wireless device can transmit a MsgA including a first transmission of a preamble and a second transmission of a transport block. The transport block may include a C-RNTI (e.g., a C-RNTI MAC CE indicating the C-RNTI). A wireless device transmitting a C-RNTI (e.g., a C-RNTI MAC CE indicating the C-RNTI) via MsgA (or via a transport block) can begin monitoring the downlink control channel with one or more RNTIs. One or more RNTIs may include C-RNTIs. One or more RNTIs may include msgB-RNTIs. One or more RNTIs may include RA-RNTIs. The wireless device may determine the msgB-RNTI and / or RA-RNTI based on radio resources used for the first and / or second transmissions (e.g., based on time (e.g., OFDM symbols, time slots, subframes, and / or SFN numbers) and / or frequency indices). Preamble indices and / or DMRS indices (e.g., port or sequence indices) used for the second transmission may be used by the wireless device to determine the msgB-RNTI and / or RA-RNTI. The wireless device may initiate a MsgBRAR window (or timer), for example, after or in response to the transmission of MsgA (or a transport block). The wireless device may monitor the control channel during the MsgB RAR window or while the timer is running. For example, if the wireless device receives at least one PDCCH addressed to C-RNTI and / or msgB-RNTI (or RA-RNTI) via the downlink control channel and during the msgB RAR window or while the timer is running, the wireless device may stop monitoring. For example, if the wireless device can receive at least one PDCCH addressed to C-RNTI and / or msgB-RNTI (or RA-RNTI) via the downlink control channel and during the msgB RAR window or while the timer is running, and / or if the PDSCH received based on the downlink artifact of at least one PDCCH is successfully decoded, the wireless device can stop monitoring.

[0344] Figure 24A and Figure 24BThis is an example diagram of a two-step RA procedure. A radio device with a C-RNTI can transmit the C-RNTI (e.g., a C-RNTI MAC CE indicating the C-RNTI) to the base station via MsgA during the two-step RA procedure. The radio device can initiate a MsgB RAR window (or timer) after transmitting MsgA (or a transport block) or in response to transmitting MsgA (or a transport block). The radio device can monitor the control channel during the MsgB RAR window or while the timer is running. A radio device that transmits the C-RNTI (e.g., a C-RNTI MAC CE indicating the C-RNTI) via MsgA can monitor the downlink control channel using the C-RNTI and / or msgB-RNTI (or RA-RNTI). For example, if the radio device receives at least one response (e.g., a success response or a fallback response) during the MsgB RAR window or while the timer is running, the radio device can stop monitoring the downlink control channel. For example, the detection of a PDCCH addressed to the C-RNTI could be a success response. For example, the detection of a PDCCH addressed to a C-RNTI and / or the reception (e.g., successful decoding) of a PDSCH indicated by a PDCCH addressed to a C-RNTI can be a success response. For example, receiving...

[0345] Figure 24AThis is an example diagram illustrating a wireless device receiving a PDCCH addressed to a C-RNTI via a downlink control channel. A wireless device transmitting a C-RNTI via MsgA (e.g., a C-RNTI MAC CE indicating the C-RNTI) can monitor the downlink control channel using the C-RNTI and / or msgB-RNTI (or RA-RNTI). The wireless device can, for example, stop monitoring the downlink control channel with C-RNTI and / or msgB-RNTI (or RA-RNTI) after receiving (and / or detecting) a PDCCH addressed to a C-RNTI, or in response to receiving (and / or detecting) a PDCCH addressed to a C-RNTI. In this case, the wireless device can determine, based on the detected PDCCH, that the two-step RA procedure was successfully completed, MsgB reception was successful, and / or contention resolution was successfully completed. For example, if the wireless device can receive (and / or detect) a PDCCH addressed to C-RNTI and / or msgB-RNTI (or RA-RNTI) via the downlink control channel and / or if the PDSCH received based on the downlink assignment of the PDCCH is successfully decoded, the wireless device can stop monitoring the downlink control channel with C-RNTI and / or msgB-RNTI (or RA-RNTI). In this example, the detected PDCCH includes a DCI containing the downlink assignment. The wireless device can receive the PDSCH (e.g., a MAC PDU) based on the downlink assignment. The received PDSCH (or MAC PDU) may include TA commands (e.g., TA command MAC CE). The wireless device may, for example, cease monitoring the downlink control channel with C-RNTI and / or msgB-RNTI (or RA-RNTI) after receiving a PDCCH addressed to C-RNTI and / or a corresponding PDSCH (or MAC PDU) including a TA command (e.g., TA command MAC CE) or in response to receiving a PDCCH addressed to C-RNTI and / or a corresponding PDSCH (or MAC PDU) including a TA command (e.g., TA command MAC CE). In this case, the wireless device may determine, based on the detected PDCCH and / or successfully decoded PDSCH (e.g., MAC PDU), that the two-step RA procedure was successfully completed, MsgB reception was successful, and / or contention resolution was successfully completed.

[0346] Figure 24BThis is an example diagram illustrating a wireless device receiving a PDCCH addressed to msgB-RNTI (or RA-RNTI) via a downlink control channel. A wireless device transmitting a C-RNTI (e.g., a C-RNTI MAC CE indicating the C-RNTI) via MsgA can monitor the downlink control channel using the C-RNTI and / or msgB-RNTI (or RA-RNTI). The wireless device can, for example, stop monitoring the downlink control channel with C-RNTI and / or msgB-RNTI (or RA-RNTI) after receiving a PDCCH addressed to msgB-RNTI (or RA-RNTI) or in response to receiving a PDCCH addressed to msgB-RNTI (or RA-RNTI). The detected PDCCH addressed to msgB-RNTI (or RA-RNTI) may include a DCI indicating a downlink assignment of a PDSCH (e.g., a MAC PDU). The wireless device can receive the PDSCH (e.g., the MAC PDU) based on the downlink assignment. The received PDSCH (e.g., MAC PDU) may include one or more responses (e.g., one or more MsgBs). The radio device may, for example, cease monitoring the downlink control channel with C-RNTI and / or msgB-RNTI (or RA-RNTI) after receiving a PDCCH addressed to C-RNTI and / or a PDCCH-based downlink assignment received PDSCH (e.g., MACPDU) based on a PDCCH addressed to C-RNTI and / or a PDCCH-based downlink assignment received PDSCH (e.g., MACPDU). The PDSCH may include a RAR (e.g., a fallback response) for MsgA. The radio device may identify the RAR (e.g., MsgB) corresponding to MsgA based on a preamble identifier that matches the preamble. For example, the RAR (e.g., MsgB) may include at least one preamble identifier. The wireless device can determine, for example, that the RAR (e.g., MsgB) in the PDSCH (or MAC PDU) corresponds to MsgA based at least on the preamble identifier of the RAR (e.g., MsgB) that matches the preamble transmitted by the wireless device to the base station via MsgA. The RAR can indicate (e.g., based on implicit or explicit indications / fields) a fallback to the four-step RA procedure for Msg3 transmission. For example, the RAR may include UL authorization and / or TA commands. The wireless device can transmit Msg3 via radio resources indicated by the UL authorization, where the UL transmission timing is adjusted based on TA commands. Msg3 may include at least a portion of a transport block. For example, the Msg3 and transport block of MsgA may be identical. For example, Msg3 may include C-RNTI.

[0347] Figure 25This is an example diagram illustrating a two-step RA procedure. The wireless device can transmit MsgA, including a first transmission of a preamble and a second transmission of a transport block. The transport block may include a CCCH SDU. The CCCH SDU may include an RRC (re)establishment request, an RRC setup request, and / or an RRC recovery request. A wireless device transmitting a CCCH SDU via MsgA may not receive a C-RNTI from the base station before transmitting MsgA. The wireless device may begin monitoring the downlink control channel with a specific RNTI. The wireless device may, for example, initiate an MsgB RAR window or timer after transmitting MsgA (or a transport block of MsgA) or in response to transmitting MsgA (or a transport block of MsgA). The wireless device may monitor the control channel during the MsgB RAR window or while the timer is running. The specific RNTI may be referred to as msgB-RNTI or RA-RNTI. The wireless device may determine a specific RNTI based on radio resources (e.g., based on time (e.g., OFDM symbols, time slots, subframes, and / or SFN numbers) and / or frequency indices) of a first transmission (e.g., for a preamble) and / or a second transmission (e.g., for a transport block). Preamble indices and / or DMRS indices (e.g., DMRS sequences and / or port indices) may be used by the wireless device to determine a specific RNTI. The wireless device may detect and / or receive a PDCCH addressed to a specific RNTI during the MsgB RAR window (or while a timer is running). A DCI received via the PDCCH may include a downlink assignment for receiving the PDSCH. The DCI may be a specific DCI whose format is predefined. For example, the DCI may be DCI format 1_0 or DCI format 1_1. The wireless device may receive and / or decode the PDSCH based on the downlink assignment. The MAC entity of the wireless device may receive a MAC PDU from the physical layer of the wireless device (e.g., parsed from the PDSCH). The physical layer can decode the PDSCH and send the data decoded and / or parsed from the PDSCH (e.g., MAC PDU) to the MAC entity. The wireless device can identify the response (e.g., MsgB) to MsgA from the MAC PDU. For example, the response may include a preamble identifier that matches the preamble transmitted by the wireless device to the base station via MsgA. The response may be a successful RAR. The response may be a fallback RAR. Explicit or implicit indicators may exist, based on which the wireless device identifies whether the received / identified response is a successful RAR or a fallback RAR. For example, there may be a field indicating the type of RAR (success or fallback) (e.g., an explicit indicator). For example, the wireless device may identify the type of RAR (success or fallback RAR) based on the format of the received RAR. For example, a successful RAR and / or a fallback RAR may include one or more fields of different types and / or different sizes. For example, the response (success or fallback RAR) may include a second field indicating the length (or size) of the response.The wireless device can identify the type of RAR (successful RAR or rollback RAR) based on the second field.

[0348] In the example, the wireless device may transmit a preamble and a transport block for the MsgA, used in a two-step RA procedure. The transport block may include an RRC request (e.g., a CCCH SDU). The RRC request (e.g., a CCCH SDU) may include an RRC (re)establishment request, an RRC setup request, and / or an RRC recovery request. A wireless device transmitting an RRC request (e.g., a CCCH SDU) via MsgA may not receive a C-RNTI from the base station before transmitting MsgA. The transport block (and / or the RRC request) may include a wireless device identifier that can be used for contention resolution. The wireless device may receive MsgB (PDSCH) as a success response or a fallback response to MsgA. For example, if MsgB is a success response to MsgA, then MsgB may include a response to an RRC request (e.g., a CCCH SDU). For example, a response to an RRC request (e.g., a CCCH SDU) may include an RRC message (e.g., an SRB RRC message). RRC messages (e.g., SRB RRC messages) may include RRC (re)establishment messages (or configurations), RRC setup messages (or configurations), and / or RRC recovery messages (or configurations), respectively, as responses to RRC (re)establishment requests, RRC setup requests, and / or RRC recovery requests transmitted by the wireless device via MsgA (or transport block).

[0349] In the example, RRC messages (e.g., SRB RRC messages) require the transmission of a relatively large number of message bits. For example, if a MsgB includes an RRC message (e.g., an SRB RRC message), the base station may not multiplex one or more MsgBs for one or more radio devices (or may multiplex a limited number of one or more MsgBs for one or more radio devices). For example, a MsgB received by a radio device from the base station as a response to MsgA (e.g., as a success response) may be divided into multiple MsgBs. At least one of the multiple MsgBs may be multiplexed with one or more MsgBs (e.g., MsgBs from other radio devices). At least one of the multiple MsgBs may be a radio device-specific message (e.g., not multiplexed with split MsgBs from other radio devices).

[0350] For example, a wireless device may receive MsgB from a base station as a response to MsgA (e.g., as a success response). MsgB may include a success RAR (e.g., referred to as MsgB1 in this specification) and an RRC message (e.g., referred to as MsgB2 in this specification). MsgB2 (e.g., the RRC message of MsgB) may include an RRC (re)establishment message (or configuration), an RRC setting message (or configuration), and / or an RRC recovery message (or configuration), as responses to an RRC (re)establishment request, an RRC setting request, and / or an RRC recovery request, respectively. MsgB1 (e.g., the success RAR of MsgB) may include one or more fields indicating at least one of the following: a preamble identifier, a UL license, a DL assignment, a TA command, and / or a contention resolution identifier. MsgB1 (e.g., the success RAR of MsgB) and / or MsgB2 (e.g., the RRC message of MsgB) may be multiplexed into a MAC PDU received by the wireless device as a response to MsgA. For example, MsgB1 and MsgB2 are multiplexed into a MAC PDU. The wireless device may receive MsgB1 and MsgB2 from a separate PDSCH. Alternatively, MsgB1 and MsgB2 may not be multiplexed into a MAC PDU. For example, the wireless device may receive a first PDSCH (e.g., a first MAC PDU) multiplexing MsgB1 with the RARs of other wireless devices (e.g., Msg2, MsgB1, and / or MsgB). For example, the wireless device may receive a second PDSCH (e.g., a second MAC PDU) including MsgB2. The second PDSCH may be a wireless device-specific message for the wireless device.

[0351] The wireless device may transmit MsgA, which includes an RRC request (e.g., a CCCH SDU). The wireless device may receive MsgB1 and MsgB2 as responses to MsgA via different PDSCHs. MsgB1 may include at least one of the following: a random access preamble identifier (RAPID), a contention resolution identifier, a C-RNTI, a TA command, a UL authorization, and / or a downlink assignment. MsgB2 may include an RRC message (e.g., an SRB RRC message). MsgB2 may also include one or more pieces of information that MsgB1 may not indicate (or include). For example, MsgB2 may include at least one of the following: a RAPID, a contention resolution identifier, a C-RNTI, a TA command, a UL authorization, and / or a downlink assignment. For example, the wireless device may receive a first PDSCH including a MAC PDU that multiplexes at least one MsgB1 (e.g., a MACsubPDU). MsgB1 may include at least one of the following: a RAPID, a TA command, and / or a C-RNTI. The wireless device may identify MsgB1 (or MacsubPDU) as a response corresponding to MsgA, for example, based on the RAPID of MsgB1 (e.g., MACsubPDU) that matches the preamble transmitted by the wireless device via MsgA. The wireless device may receive a second PDSCH from the base station including MsgB2. MsgB2 may be, for example, a wireless device-specific message not multiplexed with responses from other wireless devices. MsgB2 may include an RRC message (e.g., an RRC (re)establishment message, an RRC setup message, or an RRC recovery message), which may be a response to an RRC request (e.g., an RRC (re)establishment request, an RRC setup request, or an RRC recovery request, respectively). The wireless device may determine that contention resolution was successfully completed based on a match between the contention resolution identifier of MsgB1 and the wireless device identifier (ID) transmitted via MsgA.

[0352] The wireless device may receive MsgB1 (e.g., a successful RAR message for MsgB) and / or MsgB2 (e.g., an RRA message for MsgB) in one or more ways. The wireless device may transmit MsgA to the base station, including a preamble and a transport block (e.g., which may include a wireless device identifier). The wireless device may receive a DCI (via PDCCH) indicating a first downlink assignment for a first PDSCH. The wireless device may receive the first PDSCH based on a time / frequency resource allocation indicated by the first downlink assignment. The received first PDSCH may include a MAC PDU containing one or more MsgB1s. For example, the MAC PDU may also include one or more backoff responses. For example, the wireless device identifies the MsgB1 corresponding to MsgA from the MAC PDU based on a RAPID that matches the preamble. For example, the MsgB1 in the MAC PDU (e.g., a MACsubPDU) includes a field indicating a specific RAPID (e.g., in a subheader of MsgB1). If a specific RAPID matches a preamble transmitted via MsgA, the wireless device can determine that MsgB1 is a response to MsgA. MsgB1 may also include a contention resolution identifier. In this case, the wireless device can identify MsgB1 corresponding to MsgA from the MAC PDU based on the RAPID and / or the contention resolution identifier. For example, if the RAPID and / or the contention resolution identifier match the preamble and / or the wireless device identifier, respectively, the wireless device can determine that MsgB1 is a response to MsgA. In this case, the wireless device can determine that contention resolution was successfully completed based on the contention resolution identifier that matches the wireless device identifier. MsgB1 may include a second downlink assignment of a second PDSCH, which may include MsgB2. For example, the second downlink assignment is not indicated by control signals (e.g., PDCCH and / or DCI). For example, msgB1 (e.g., multiplexed in the MAC PDU) may indicate the second downlink assignment. In this case, the MAC entity of the wireless device can notify the physical layer of the wireless device of the second downlink assignment, causing the physical layer of the wireless device to receive the second PDSCH. The wireless device may receive a second PDSCH based on a second downlink assignment. The second PDSCH may include MsgB2, which includes an RRC message (e.g., RRC (re)establishment, RRC setup, or RRC recovery), which may be a response to a CCCH SDU (e.g., an RRC (re)establishment request, an RRC setup request, or an RRC recovery request, respectively).

[0353] Figure 26This is an example of a two-step RA procedure. The radio device initiating the two-step RA procedure may transmit a MsgA including a preamble and a transport block. The transport block may include an RRC request message (e.g., a CCCH SDU). For example, the RRC request message includes one of the following: an RRC (re)establishment request, an RRC setup request, and / or an RRC recovery request. The radio device may, for example, begin monitoring the downlink control channels of MsgB1 and MsgB2 after transmitting the MsgA or in response to transmitting the MsgA. The transport block (or RRC request message) may include a radio device identifier that can be used for contention resolution. The radio device may, for example, start a window (or timer) after transmitting the MsgA or in response to transmitting the MsgA. The radio device may receive a PDCCH including a DCI that schedules the first PDSCH during the window period (or while the timer is running). The PDCCH may be addressed to a specific RNTI (e.g., scrambled with a specific RNTI). For example, the radio device may determine the specific RNTI based on the time and / or frequency radio resources used for the transmission of the preamble and / or the transport block. The wireless device can further determine a specific RNTI based on the RAPID of the preamble and / or DMRS information (e.g., port number, sequence number, etc.) of the transport block. The first PDSCH may include a MAC PDU containing MsgB1. Multiple MsgB1s may exist in the MAC PDU. The wireless device can identify MsgB1 from the MAC PDU based on the RAPID. For example, if the RAPID indicated by a field of MsgB1 (e.g., a subheader) matches the identifier of the preamble, the wireless device will determine that MsgB1 is a response to MsgA. MsgB1 may also include a contention resolution identifier. In this case, the wireless device can identify MsgB1 from the MAC PDU based on the RAPID and / or the wireless device identifier. For example, if the RAPID indicated by the first field (e.g., subheader) of MsgB1 matches the identifier of the preamble, and / or the contention resolution identifier indicated by the second field in MsgB1 matches the radio device identifier transmitted to the base station via a transport block (or RRC message request), the radio device identifies MsgB1 as a response to MsgA. MsgB1 may also include DL assignment. The DL assignment may include DL scheduling information. The radio device may receive the second PDSCH based on the DL scheduling information. For example, the DL scheduling information indicates at least one of the following: the time and / or frequency radio resource indication of the DL transmission of the second PDSCH (e.g., based on time and / or frequency indexes), the size (or length) of the transport block (or packet, or message) transmitted via the second PDSCH, and / or the modulation and coding scheme of the second PDSCH. The second PDSCH received by the radio device from the base station may include MsgB2. MsgB2 may include a response to an RRC request message transmitted via a transport block.For example, MsgB2 includes at least one of the following: an RRC (re)establishment message, an RRC setup message, or an RRC recovery message, which may be a response to a CCCH SDU (e.g., an RRC (re)establishment request, an RRC setup request, or an RRC recovery request, respectively).

[0354] The wireless device may receive MsgB1 and MsgB2 in one or more ways. The wireless device may transmit MsgA, including a preamble and a transport block, to the base station. The transport block may include a wireless device identifier. The wireless device may receive a first DCI (via a first PDCCH) indicating a first downlink assignment of a first PDSCH. The wireless device may receive the first PDSCH based on a time / frequency resource allocation indicated by the first downlink assignment. The received first PDSCH may include (or resolve to) a MAC PDU containing one or more MAC subPDUs. For example, at least one of the one or more MAC subPDUs may include MsgB1. For example, the wireless device may identify at least one of the one or more MAC subPDUs as MsgB1 corresponding to MsgA based on the identifier of the preamble and from the one or more MAC subPDUs. MsgB1 may also include a contention resolution identifier. In this scenario, the radio device can identify MsgB1 corresponding to MsgA from one or more MACsubPDUs based on a RAPID that matches the identifier of the preamble and / or a contention-resolved identifier for MsgB1 that matches the radio device identifier. MsgB1 may also include a C-RNTI. The radio device can monitor the downlink control channel based on the C-RNTI. The radio device can receive a second PDCCH including a second DCI via the downlink control channel. The second PDCCH may be addressed to a C-RNTI (or scrambled with a C-RNTI). The second DCI may include a second downlink assignment of the second PDSCH. The second PDSCH may include MsgB2. The radio device can receive the second PDSCH based on the second downlink assignment. The second PDSCH may include MsgB2, which includes an RRC message (e.g., RRC (re)establishment, RRC setting, or RRC recovery), which may be a response to a CCCH SDU (e.g., an RRC (re)establishment request, RRC setting request, or RRC recovery request, respectively).

[0355] Figure 27This is an example of a two-step RA procedure. The radio device initiating the two-step RA procedure may transmit a MsgA including a preamble and a transport block. The transport block may include an RRC request message (e.g., a CCCH SDU). For example, the RRC message includes one of the following: an RRC (re)establishment request, an RRC setup request, and / or an RRC recovery request. The radio device may, for example, begin monitoring the downlink control channels of MsgB1 and MsgB2 after transmitting the MsgA or in response to transmitting the MsgA. The transport block (or RRC message) may include a radio device identifier that can be used for contention resolution. The radio device may, for example, start a window (or timer) after transmitting the MsgA or in response to transmitting the MsgA. The radio device may receive a first PDCCH including a first DCI that schedules a first PDSCH during the window period (or while the timer is running). The first PDCCH may be addressed to a specific RNTI (e.g., scrambled with a specific RNTI). For example, the radio device may determine the specific RNTI based on the time and / or frequency radio resources used for the transmission of the preamble and / or the transport block. The wireless device may further determine a specific RNTI based on the RAPID of the preamble and / or DMRS information (e.g., port number, sequence number, etc.) of the transport block. The first DCI may include a first downlink assignment scheduling downlink reception of the first PDSCH. The wireless device may receive the first PDSCH based on the first downlink assignment. The first PDSCH may include a MAC PDU containing MsgB1. For example, the MAC PDU may include one or more MAC subPDUs. For example, at least one of the one or more MAC subPDUs may include MsgB1. The wireless device may identify MsgB1 from one or more MAC subPDUs based on the identifier of the preamble. For example, if the RAPID indicated by a field of MsgB1 (e.g., a field in a subheader) matches the identifier of the preamble, then among the one or more MAC subPDUs, the wireless device identifies at least one MAC subPDU as MsgB1 (e.g., as a response to MsgA). MsgB1 may also include a contention resolution identifier. In this scenario, the wireless device can identify MsgB1 from one or more MACsubPDUs based on the preamble identifier and / or the wireless device identifier. For example, if the RAPID indicated by the first field in MsgB1 matches the preamble identifier, and / or the contention resolution identifier indicated by the second field in MsgB1 matches the wireless device identifier transmitted to the base station via a transport block (or RRC message request), then the wireless device identifies at least one MACsubPDU from the one or more MACsubPDUs as MsgB1 (e.g., in response to MsgA). MsgB1 may also include a specific RNTI (e.g., Figure 27 The specific RNTI is, for example, a C-RNTI. The radio device can monitor the downlink control channel for the second PDSCH based on the specific RNTI. The radio device can detect the second PDSCH addressed to a specific RNTI (e.g., a C-RNTI) (or scrambled with a specific RNTI (e.g., a C-RNTI)). The second PDSCH may include a second DCI. The second DCI may include a second downlink assignment for the second PDSCH. The second downlink assignment may include DL scheduling information. The radio device can receive the second PDSCH based on the DL scheduling information. For example, the DL scheduling information indicates at least one of the following: time and / or frequency radio resource indications for the DL transmission of the second PDSCH (e.g., based on time and / or frequency indexes), the size (or length) of the transport block (or packet, or message) transmitted via the second PDSCH, and / or the modulation and coding scheme of the second PDSCH. The second PDSCH received by the radio device from the base station may include MsgB2. MsgB2 may include a response to an RRC request message transmitted via the transport block. For example, MsgB2 includes at least one of the following: an RRC (re)establishment message, an RRC setup message, or an RRC recovery message, which may be a response to a CCCH SDU (e.g., an RRC (re)establishment request, an RRC setup request, or an RRC recovery request, respectively).

[0356] In a two-step RA procedure, MsgB may include two responses, MsgB1 and MsgB2. The wireless device may receive a single PDSCH (e.g., a single MAC PDU) including MsgB1 and MsgB2. The wireless device may receive MsgB1 and MsgB2 via different (or separate) PDSCHs (e.g., a first PDSCH and a second PDSCH). MsgB1 may include a contention resolution identifier. The wireless device may determine whether contention resolution was successful based on the contention resolution identifier. For example, the wireless device may transmit MsgA including a preamble and a transport block. The transport block may include the wireless device identifier of the wireless device. If the contention resolution identifier in the received MsgB1 matches the wireless device identifier, the wireless device may determine that contention resolution was successful. The wireless device may attempt to receive MsgB2 after determining successful contention resolution or in response to determining successful contention resolution. The wireless device may receive MsgB2 after receiving MsgB1 (e.g., successful decoding of MsgB1) and / or determining a successful contention resolution, or in response to receiving MsgB1 (e.g., successful decoding of MsgB1) and / or determining a successful contention resolution. MsgB2 may include a response to an RRC request transmitted via a transport block. For example, the wireless device may receive MsgB2 but may not be able to decode it. For example, if the wireless device fails to decode MsgB2, the wireless device may not set up radio bearers (e.g., SRBs and / or data radio bearers, DRBs) to the network (or to the base station). If the wireless device does not receive a response to an RRC request (e.g., RRC (re)establishment, RRC setup, or RRC recovery), the wireless device may not set up radio bearers (e.g., SRBs and / or DRBs) to the network (or to the base station). This could be a situation where the wireless device determines that contention resolution is successful, but the wireless device may not set up, (re)establish, or resume radio bearers (e.g., SRBs and / or DRBs) with the network (or base station).

[0357] If the wireless device fails to decode MsgB2, it may attempt to receive one or more other MsgB2s. A two-step RA procedure can support a HARQ procedure for receiving MsgB2. The wireless device may successfully decode the second MsgB2. The wireless device may transmit an ACK indicator (e.g., a UCI including the ACK indicator, via PUCCH) to the base station after successfully decoding the second MsgB2 or in response to successful decoding of the second MsgB2.

[0358] For example, if the wireless device fails to decode MsgB2 (e.g., the initial transmission of MsgB2), the wireless device may transmit a NACK indicator to the base station. For example, the wireless device may transmit a UCI including the NACK indicator to the base station via the PUCCH. The DCI scheduling the reception of MsgB2 (e.g., the initial transmission of MsgB2) may indicate the radio resources of the PUCCH. The wireless device may attempt to receive a second MsgB2 (e.g., a retransmission of MsgB2) after transmitting the NACK indicator or in response to transmitting the NACK indicator. If the wireless device fails to decode the second MsgB2, the wireless device may transmit a second NACK indicator via a second PUCCH (e.g., using a UCI). The second DCI scheduling the reception of the second MsgB2 (e.g., a second transmission of MsgB2) may indicate the radio resources of the second PUCCH. The wireless device may attempt to receive a third MsgB2 (e.g., a retransmission of MsgB2) after transmitting the second NACK indicator or in response to transmitting the NACK indicator. The wireless device can repeat this process N times, for example, until the wireless device successfully decodes MsgB2 based on N retransmissions of MsgB2.

[0359] Wireless devices can monitor downlink control signaling in a regular manner (e.g., in each time slot and / or in each symbol) to receive uplink grants and / or downlink assignments. Regular monitoring of downlink control signaling can be beneficial, for example, because the wireless device can react to changes in traffic behavior. This benefit may come at the cost of power consumption. For example, packet data traffic can be bursty. For instance, packet data traffic can be periods of intermittent transmission activity followed by long periods of silence. To reduce power consumption of wireless devices, radio technologies (e.g., Wi-Fi, LTE, and / or NR) can employ mechanisms for discontinuous reception (DRX).

[0360] According to an exemplary embodiment, multiple times, durations, and time intervals are used for DRX operation of a wireless device. These multiple times, durations, and time intervals may be referred to as one or more different methods or names and may be interchanged with one or more different methods or names. For example, the on-duration used in DRX operation may be referred to as on-duration, on-duration of DRX operation, DRX on-duration, etc. Similarly, the active time used in DRX operation may be referred to as active time, active time of DRX operation, DRX active time, etc. Time periods (e.g., durations and / or time intervals) for which the wireless device is not determined as active time for DRX operation may be referred to as inactive time (of DRX operation), inactive time (of DRX operation), DRX inactive time, non-DRX active time, etc. For example, an inactive timer used in DRX operation may be referred to as an inactive (or inactive) timer, inactive (or inactive) timer of DRX operation, DRX inactive (or inactive) timer, etc.

[0361] In the example, the wireless device can monitor the downlink channel (e.g., the downlink control channel) using a DRX period. The DRX period can be predefined and / or configurable. The wireless device can monitor the downlink control channel for downlink control signaling during a first time interval (e.g., an on duration and / or an active time) based on the DRX period. For example, the first time interval can be configurable and / or adjustable (e.g., extended) based on DL and / or UL transmissions. For example, the wireless device can adjust (e.g., extend) the first time interval if it receives an uplink grant (e.g., for a new transmission and / or for a retransmission) and / or a downlink assignment. During a second time interval, the wireless device may not monitor the downlink control channel (e.g., disable receiver circuitry). For example, the second time interval may not overlap with the first time interval. For example, the second time interval can be a period other than the first time interval (e.g., continuous, discontinuous, and / or a combination thereof). The wireless device can reduce power consumption based on monitoring the downlink control channel during a specific time interval (e.g., the first time interval). For example, the longer the period, the lower the power consumption. The base station can control / configure the cycle based on one or more parameters described in this specification.

[0362] The wireless device may, for example, receive control messages (e.g., RRC messages, MAC CE, DCI, and / or combinations thereof) from a base station to schedule the reception and / or transmission of data. In this case, the wireless device may be scheduled for another reception and / or transmission of data. In the example, the wireless device may be scheduled for transmissions for data retransmission and / or HARQ feedback. In the example, the wireless device may receive a UL license, based on which it may transmit a certain amount of data in a buffer during a scheduled transmission. For example, the wireless device may not be able to transmit all the data in the buffer during a scheduled transmission. Additional UL licenses (e.g., scheduled transmission times) may be required to transmit the remaining data in the buffer.

[0363] For example, if no additional opportunity is scheduled in the current activity cycle, a radio device in DRX operation may wait until the next activity cycle. This can result in delays. A radio device may remain active for a certain period of time after being scheduled (e.g., a configurable time). For example, when a radio device receives scheduling information (e.g., DL assignment and / or UL authorization), it may (re)start a timer (e.g., an inactive timer). A radio device that has (re)started a timer (e.g., an inactive timer) may continue monitoring the downlink control channel (e.g., remain active) until the timer expires.

[0364] The wireless device may perform DRX operations based on one or more timers. The one or more timers may be at least one of the following: drx-onDurationTimer, drx-InactivityTimer, drx-RetransmissionTimerDL, drx-RetransmissionTimerUL, drx-ShortCycleTimer, drx-HARQ-RTT-TimerDL, and / or drx-HARQ-RTT-TimerUL. The timer value for each of the one or more timers may be defined based on the number of TTIs, such as the number of OFDM symbols, the number of time slots, the number of subframes, the number of system frames, etc. The timer value for each of the one or more timers may be defined based on a time value, such as milliseconds, microseconds, seconds, etc.

[0365] Figure 28This is an example of DRX operation according to an exemplary embodiment of the present disclosure. The wireless device may receive a message including configuration parameters. The configuration parameters may indicate the duration of a long DRX period and / or a short DRX period. The wireless device may monitor the downlink control channel within a first time interval (e.g., during the DRX on duration and / or DRX activity period) via one or more PDCCH monitoring opportunities. The wireless device may determine one or more PDCCH monitoring opportunities based on the configuration parameters. For example, the wireless device determines the first time interval at the start of a DRX period (e.g., a long DRX period and / or a short DRX period). For example, the configuration parameters include a first timer value for a first timer. The wireless device may start the first time interval in response to the expiration of the first timer (e.g., the first timer reaches its first timer value). For example, if no PDCCH is received during the first time interval, the wireless device may stop monitoring. For example, the wireless device may shut down receiver circuitry, for example, based on stopping monitoring. For example, if the wireless device receives a PDCCH during the first time interval, the wireless device may continue monitoring the downlink control channel. For example, a wireless device may (re)start a second timer (e.g., an inactive timer) with a second timer value (e.g., indicated by configuration parameters) in response to receiving a PDCCH during a first time interval. The wireless device may continue monitoring the downlink control channel while the second timer is running (e.g., during additional PDCCH monitoring). For example, if the wireless device receives a PDCCH while the second timer is running, the wireless device may (re)start the second timer (e.g., an inactive timer). For example, if no PDCCH is received, for example, if the second timer expires, the wireless device may stop monitoring. One or more DRX cycl...

Claims

1. A communication method, comprising: One or more configuration parameters for a two-step random access (RA) procedure are received by the wireless device; Based on one or more configuration parameters, a message for the two-step RA procedure is sent, the message including a preamble and a transport block; and During the DRX activity time of the discontinuous reception (DRX) operation of the wireless device, a response to the message is received, wherein: The DRX activity time is based on a time window for receiving the response to the message, and The time window begins at least one symbol after the transmission timing of the transmission block.

2. The method according to claim 1, wherein, The transmission block indicates the identity of the wireless device.

3. The method according to claim 1, further comprising determining, based on the time window, that the DRX operation is within the DRX activity time.

4. The method of claim 1, further comprising stopping the time window in response to receiving the response.

5. The method according to claim 1, wherein, The time window begins at a first symbol in the control resource set of the wireless device, the first symbol being at least one symbol following the transmission timing.

6. The method of claim 1, wherein the transmit block includes a C-RNTI Media Access Control (MAC) element (CE) indicating the Cell Radio Network Temporary Identifier (C-RNTI) of the wireless device.

7. The method of claim 6, further comprising, in response to the response and based on the transport block including the C-RNTI MAC CE, monitoring one or more downlink control channels via the C-RNTI.

8. The method of claim 6, wherein the response is downlink control information (DCI) addressed to the C-RNTI.

9. The method of claim 1, further comprising, in response to receiving the response, ceasing monitoring of one or more downlink control channels based on determining that the DRX operation is not during the DRX activity period.

10. The method of claim 1, further comprising, in response to the response, using a radio network temporary identifier to monitor one or more downlink control channels.

11. A wireless device comprising: One or more processors; as well as A memory storing instructions that, when executed by the one or more processors, cause the wireless device to: Receive one or more configuration parameters for the two-step random access (RA) procedure; Based on the configuration parameters, a message for the two-step RA is sent, the message including a preamble and a transport block; as well as During the DRX activity time of the discontinuous reception (DRX) operation of the wireless device, a response to the message is received, wherein: The DRX activity time is based on a time window for receiving the response to the message, and The time window begins at least one symbol after the transmission timing of the transmission block.

12. The wireless device according to claim 11, wherein, The transmission block indicates the identity of the wireless device.

13. The wireless device of claim 11, wherein the instruction further causes the wireless device to determine, based on the time window, that the DRX operation is within the DRX activity time.

14. The wireless device of claim 11, further comprising stopping the time window in response to receiving the response.

15. The wireless device according to claim 11, wherein, The time window begins at a first symbol in the control resource set of the wireless device, the first symbol being at least one symbol following the transmission timing.

16. The wireless device of claim 11, wherein the transmit block includes a C-RNTI Media Access Control (MAC) element (CE) indicating the Cell Radio Network Temporary Identifier (C-RNTI) of the wireless device.

17. The wireless device according to claim 16, wherein, The instruction also causes the wireless device to monitor one or more downlink control channels via the C-RNTI in response to the response and based on the transport block including the C-RNTI MAC CE.

18. The wireless device of claim 16, wherein the response is downlink control information (DCI) addressed to the C-RNTI.

19. The wireless device of claim 11, wherein the instruction further causes the wireless device to stop monitoring one or more downlink control channels in response to receiving the response, based on determining that the DRX operation is not during the DRX activity period.

20. A base station, comprising: One or more processors; as well as A memory storing instructions that, when executed by the one or more processors, cause the base station to: Send one or more configuration parameters for the two-step random access (RA) procedure to the wireless device; Based on one or more configuration parameters, receive a message for the two-step RA, the message including a preamble and a transport block; as well as During the DRX activity time of the discontinuous reception (DRX) operation of the wireless device, a response to the message is sent, wherein: The DRX activity time is based on a time window for receiving the response to the message, and The time window begins at least one symbol after the transmission timing of the transmission block.

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