WO2023070519A1

WO2023070519A1 - Indication of reconfigurable intelligent surfaces (ris) presence in network

Info

Publication number: WO2023070519A1
Application number: PCT/CN2021/127402
Authority: WO
Inventors: Ahmed Elshafie; Hung Dinh LY; Yu Zhang
Original assignee: Qualcomm Incorporated
Priority date: 2021-10-29
Filing date: 2021-10-29
Publication date: 2023-05-04

Abstract

A base station may identify whether at least one RIS is present in a coverage area of the base station. The base station may transmit to a UE, and the UE may receive from the base station, a first indication of whether the at least one RIS is present in the coverage area. When at least one RIS is present, the base station may further transmit to the UE, and the UE may further receive from the base station, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS. The UE may forward the indications associated with the at least one RIS to additional UEs via a sidelink.

Description

INDICATION OF RECONFIGURABLE INTELLIGENT SURFACES (RIS) PRESENCE IN NETWORK

TECHNICAL FIELD

The present disclosure relates generally to communication systems, and more particularly, to indication of the presence or absence of a reconfigurable intelligent surface (RIS) in a wireless communication system.

INTRODUCTION

Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level An example telecommunication standard is 5G New Radio (NR) . 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT) ) , and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB) , massive machine type communications (mMTC) , and ultra-reliable low latency communications (URLLC) . Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

BRIEF SUMMARY

The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a first user equipment (UE) . The apparatus may receive, from a base station or a second UE, a first indication of whether at least one reconfigurable intelligent surface (RIS) is present in a coverage area of the base station. The apparatus may communicate with the base station or another UE based on the first indication.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided. The apparatus may be a base station. The apparatus may identify whether at least one RIS is present in a coverage area of the base station. The apparatus may transmit, to a UE, a first indication of whether the at least one RIS is present in the coverage area.

To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network.

FIG. 2A is a diagram illustrating an example of a first frame, in accordance with various aspects of the present disclosure.

FIG. 2B is a diagram illustrating an example of DL channels within a subframe, in accordance with various aspects of the present disclosure.

FIG. 2C is a diagram illustrating an example of a second frame, in accordance with various aspects of the present disclosure.

FIG. 2D is a diagram illustrating an example of UL channels within a subframe, in accordance with various aspects of the present disclosure.

FIG. 3 is a diagram illustrating an example of a base station and user equipment (UE) in an access network.

FIG. 4A is a diagram illustrating an example wireless communication system.

FIG. 4B is a diagram illustrating an example wireless communication system.

FIG. 5A is a diagram illustrating an example wireless communication system in which sidelink communication may be used.

FIG. 5B is a diagram illustrating an example wireless communication system 500B in which sidelink communication and a RIS may be used.

FIG. 6A is a diagram of a communication flow associatedwith a 4-step random access channel (RACH) procedure.

FIG. 6B is a diagram of a communication flow associated with a 2-step RACH procedure.

FIG. 7 is a diagram illustrating a structure of a sidelink SSB (S-SSB) .

FIG. 8 is a diagram of a communication flow of a method of wireless communication.

FIG. 9 is a flowchart of a method of wireless communication.

FIG. 10 is a flowchart of a method of wireless communication.

FIG. 11 is a flowchart of a method of wireless communication.

FIG. 12 is a flowchart of a method of wireless communication.

FIG. 13 is a diagram illustrating an example of a hardware implementation for an example apparatus.

FIG. 14 is a diagram illustrating an example of a hardware implementation for an example apparatus.

DETAILED DESCRIPTION

The detailed description set forth below in connection with the appended drawings is intended as a description of various configurations and is not intended to represent the only configurations in which the concepts descried herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be descried in the following detailed description and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as “elements” ) . These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.

By way of example, an element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs) , central processing units (CPUs) , application processors, digital signal processors (DSPs) , reduced instruction set computing (RISC) processors, systems on a chip (SoC) , baseband processors, field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other suitable hardware configured to perform the various functionality descried throughout this disclosure. One or more processors in the processing system may execute software. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, etc., whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.

Accordingly, in one or more example embodiments, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on or encoded as one or more instructions or code on a computer-readable medium. Computer-readable media includes computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise a random-access memory (RAM) , a read-only memory (ROM) , an electrically erasable programmable ROM (EEPROM) , optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of the types of computer-readable media, or any other medium that can be used to store computer executable code in the form of instructions or data structures that can be accessedby a computer.

While aspects and implementations are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios, Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, implementations and/or uses may come about via integrated chip implementations and other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, artificial intelligence (AI) -enabled devices, etc. ) . While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur, Implementations may range a spectrum from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more aspects of the described innovations. In some practical settings, devices incorporating described aspects and features may also include additional components and features for implementation and practice of claimed and described aspect. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes (e.g., hardware components including antenna, radio frequency (RF) -chains, power amplifiers, modulators, buffer, processor (s) , interleaver, adders/summers, etc. ) , It is intended that innovations described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc. of varying sizes, shapes, and constitution.

FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN) ) includes base stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and another core network 190 (e.g., a 5G Core (5GC) ) . The base stations 102 may include macrocells (high power cellular base station) and/or small cells (low power cellular base station) . The macrocells include base stations. The small cells include femtocells, picocells, and microcells.

The base stations 102 configured for 4G LTE (collectively referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) ) may interface with the EPC 160 through first backhaul links 132 (e.g., S1 interface) . The base stations 102 configured for 5G NR (collectively referred to as Next Generation RAN (NG-RAN) ) may interface with core network 190 through second backhaul links 184. In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity) , inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages. The base stations 102 may communicate directly or indirectly (e.g., through the EPC 160 or core network 190) with eachother over third backhaul links 134 (e.g., X2 interface) . The first backhaul links 132, the second backhaul links 184, and the third backhaul links 134 may be wired or wireless.

The base stations 102 may wirelessly communicate with the UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102′ may have a coverage area 110′ that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macrocells may be known as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs) , which may provide service to a restricted group known as a closed subscriber group (CSG) . The communication links 120 betweenthe base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and/or downlink (DL) (also referredto as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be through one or more carriers. The base stations 102 /UEs 104 mayuse spectrum up to YMHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (x component carriers) used for transmission in each direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respectto DL and UL (e.g., more or fewer carriers may be allocated for DL than for UL) . The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell) .

Certain UEs 104 may communicate with each other using device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL/UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) . D2D communication may be through a variety of wireless D2D communications systems, such as for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

The wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154, e.g., in a 5 GHz unlicensed frequency spectrum or the like. When communicating in an unlicensed frequency spectrum, the STAs 152 /AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.

The small cell 102′ may operate in a licensed and/or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102′ may employ NR and use the same unlicensed frequency spectrum (e.g., 5 GHz, or the like) as usedby the Wi-Fi AP 150. The small cell 102′, employing NR in anunlicensed frequency spectrum, may boost coverage to and/or increase capacity of the access network.

The electromagnetic spectrum is often subdivided, based on frequency/wavelength, into various classes, bands, channels, etc. In 5G NR, two initial operating bands have been identified as frequency range designations FR1 (410 MHz -7.125 GHz) and FR2 (24.25 GHz -52.6 GHz) . Although a portion of FR1 is greater than 6 GHz, FR1 is often referred to (interchangeably) as a “sub-6 GHz” band in various documents and articles. A similar nomenclature issue sometimes occurs with regard to FR2, which is often referredto (interchangeably) as a “millimeter wave” band in documents and articles, despite being different from the extremely high frequency (EHF) band (30 GHz -300 GHz) which is identified by the International Telecommunications Union (ITU) as a “millimeter wave” band.

The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. Recent 5G NR studies have identified an operating band for these mid-band frequencies as frequency range designation FR3 (7.125 GHz-24.25 GHz) . Frequency bands falling within FR3 may inherit FR1 characteristics and/or FR2 characteristics, and thus may effectively extend features of FR1 and/or FR2 into mid-band frequencies, In addition, higher frequency bands are currently being explored to extend 5G NR operation beyond 52.6 GHz. For example, three higher operating bands have been identified as frequency range designations FR2-2 (52.6 GHz -71 GHz) , FR4 (52.6 GHz -114.25 GHz) , and FR5 (114.25 GHz -300 GHz) . Each of these higher frequency bands falls within the EHF band.

With the above aspects in mind, unless specifically stated otherwise, it should be understood that the term “sub-6 GHz” or the like if used herein may broadly represent frequencies that may be less than 6 GHz, may be within FR1, or may include mid-band frequencies. Further, unless specifically stated otherwise, it should be understood that the term “millimeter wave” or the like if used herein may broadly represent frequencies that may include mid-band frequencies, may be within FR2, FR4, FR2-2, and/or FR5, or may be within the EHF band.

A base station 102, whether a small cell 102′ or a large cell (e.g., macro base station) , may include and/or be referredto as an eNB, gNodeB (gNB) , or another type of base station. Some base stations, such as gNB 180 may operate in a traditional sub 6 GHz spectrum, in millimeter wave frequencies, and/or near millimeter wave frequencies in communication with the UE 104. When the gNB 180 operates in millimeter wave or near millimeter wave frequencies, the gNB 180 may be referred to as a millimeter wave base station. The millimeter wave base station 180 may utilize beamforming 182 with the UE 104 to compensate for the path loss and short range. The base station 180 and the UE 104 may each include a plurality of antennas, such as antenna elements, antenna panels, and/or antenna arrays to facilitate the beamforming.

The base station 180 may transmit a beamformed signal to the UE 104 in one or more transmit directions 182′. The UE 104 may receive the beamformed signal from the base station 180 in one or more receive directions 182". The UE 104 may also transmit a beamformed signal to the base station 180 in one or more transmit directions. The base station 180 may receive the beamformed signal from the UE 104 in one or more receive directions. The base station 180 /UE 104 may perform beam training to determine the best receive and transmit directions for each of the base station 180 /UE 104. The transmit and receive directions for the base station 180 may or may not be the same. The transmit and receive directions for the UE 104 may or may not be the same.

The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a PacketData Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and/or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN) , and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start/stop) and for collecting eMBMS related charging information.

The core network 190 may include an Access and Mobility Management Function (AMF) 192, otherAMFs 193, a Session Management Function (SMF) 194, and aUser Plane Function (UPF) 195. The AMF 192 may be in communication with a Unified Data Management (UDM) 196. The AMF 192 is the control node that processes the signaling between the UEs 104 and the core network 190. Generally, the AMF 192 provides QoS flow and session management. All user Internet protocol (IP) packets are transferred through the UPF 195. The UPF 195 provides UE IP address allocation as well as other functions. The UPF 195 is connected to the IP Services 197. The IP Services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a Packet Switch (PS) Streaming (PSS) Service, and/or other IP services.

The base station may include and/or be referredto as a gNB, Node B, eNB, an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , atransmit reception point (TRP) , or some other suitable terminology. The base station 102 provides an access point to the EPC 160 or core network 190 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA) , a satellite radio, a global positioning system, amultimedia device, a video device, a digital audio player (e.g., MP3 player) , a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor/actuator, a display, or any other similar functioning device. Some of the UEs 104 may be referredto as lot devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc. ) . The UE 104 may also be referredto as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology. In some scenarios, the term UE may also apply to one or more companion devices such as in a device constellation arrangement. One or more of these devices may collectively access the network and/or individually access the network.

Referring again to FIG. 1, in certain aspects, the UE 104 may include a RIS management component 198 that may be configured to receive, from a base station or a second UE, a first indication of whether at least one RIS is present in a coverage area of the base station. The RIS management component 198 may be configured to communicate with the base station or another UE based on the first indication. In certain aspects, the base station 180 may include a RIS management component 199 that may be configured to identify whether at least one RIS is present in a coverage area of the base station. The RIS management component 199 may be configured to transmit, to a UE, a first indication of whether the at least one RIS is present in the coverage area. Although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

FIG. 2A is a diagram 200 illustrating an example of a first subframe within a 5G NR frame structure. FIG. 2B is a diagram 230 illustrating an example of DL channels within a 5G NR subframe. FIG. 2C is a diagram 250 illustrating an example of a second subframe within a 5G NR frame structure. FIG. 2D is a diagram 280 illustrating an example of UL channels within a 5G NR subframe. The 5G NR frame structure may be frequency division duplexed (FDD) in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for either DL or UL, or may be time division duplexed (TDD) in which for a particular set of subcarriers (carrier system bandwidth) , subframes within the set of subcarriers are dedicated for both DL and UL. In the examples provided by FIGs. 2A, 2C, the 5G NR frame structure is assumed to be TDD, with subframe 4 being configured with slot format 28 (with mostly DL) , where D is DL, U is UL, and F is flexible for use betweenDL/UL, and subframe 3 being configured with slot format 1 (with all UL) . While

subframes

3, 4 are shown with slot formats 1, 28, respectively, any particular subframe may be configured with any of the various available slot formats 0-61. Slot formats 0, 1 are all DL, UL, respectively. Other slot formats 2-61 include a mix of DL, UL, and flexible symbols. UEs are configured with the slot format (dynamically through DL control information (DCI) , or semi-statically/statically through radio resource control (RRC) signaling) through a received slot format indicator (SFI) . Note that the description infra applies also to a 5G NR frame structure that is TDD.

FIGs. 2A-2D illustrate a frame structure, and the aspects of the present disclosure may be applicable to other wireless communication technologies, which may have a different frame structure and/or different channels. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms) . Eachsubframe may include one or more time slots. Subframes may also include mini-slots, which may include 7, 4, or 2 symbols. Each slot may include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is normal or extended. For normal CP, each slot may include 14 symbols, and for extended CP, each slot may include 12 symbols. The symbols on DL may be CP orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbols. The symbols on UL may be CP-OFDM symbols (for high throughput scenarios) or discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) symbols (also referred to as single carrier frequency-division multiple access (SC-FDMA) symbols) (for power limited scenarios; limited to a single stream transmission) . The number of slots within a subframe is based on the CP and the numerology. The numerology defines the subcarrier spacing (SCS) and, effectively, the symbol length/duration, which is equal to 1/SCS.

For normal CP (14 symbols/slot) , different numerologies μ 0 to 4 allow for 1, 2, 4, 8, and 16 slots, respectively, per subframe. For extended CP, the numerology 2 allows for 4 slots per subframe. Accordingly, for normal CP and numerology μ, there are 14 symbols/slot and 2 ^μ slots/subframe. The subcarrier spacing may be equal to 2 ^μ*15 kHz, where /μ is the numerology 0 to 4. As such, the numerology μ=0 has a subcarrier spacing of 15 kHz and the numerology μ=4 has a subcarrier spacing of 240 kHz. The symbol length/duration is inversely related to the subcarrier spacing. FIGs. 2A-2D provide an example of normal CP with 14 symbols per slot and numerology μ=2 with 4 slots per subframe. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is approximately 16.67 μs. Within a set of frames, there may be one or more different bandwidth parts (BWPs) (see FIG. 2B) that are frequency division multiplexed. Each BWP may have a particular numerology and CP (normal or extended) .

A resource grid may be used to represent the frame structure. Each time slot includes a resource block (RB) (also referred to as physical RBs (PRBs) ) that extends 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs) . The number of bits carried by each RE depends on the modulation scheme.

As illustrated in FIG. 2A, some of the REs carry reference (pilot) signals (RS) for the UE.The RS may include demodulation RS (DM-RS) (indicated as R for one particular configuration, but other DM-RS configurations are possible) and channel state information reference signals (CSI-RS) for channel estimation at the UE. The RS may also include beam measurement RS (BRS) , beam refinement RS (BRRS) , and phase tracking RS (PT-RS) .

FIG. 2B illustrates an example of various DL channels within a subframe of a frame. The physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs) , each CCE including six RE groups (REGs) , each REG including 12 consecutive REs in an OFDM symbol of an RB. A PDCCH within one BWP may be referred to as a control resource set (CORESET) . A UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., common search space, UE-specific search space) during PDCCH monitoring occasions on the CORESET, where the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at greater and/or lower frequencies across the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of particular subframes of a frame. The PSS is used by a UE 104 to determine subframe/symbol timing and a physical layer identity. A secondary synchronization signal (SSS) may be within symbol 4 of particular subframes of a frame. The SSS is used by a UE to determine a physical layer cell identity group number and radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine a physical cell identifier (PCI) . Based on the PCI, the UE can determine the locations of the DM-RS. The physical broadcast channel (PBCH) , which carries a master information block (MIB) , may be logically grouped with the PSS and SSS to form a synchronization signal (SS) /PBCH block (also referred to as SS block (SSB) ) . The MIB provides a number of RBs in the system bandwidth and a system frame number (SFN) . The physical downlink shared channel (PDSCH) carries user data, broadcast system information not transmitted through the PBCH such as system information blocks (SIBs) , and paging messages.

As illustrated in FIG. 2C, some of the REs carry DM-RS (indicated as R for one particular configuration, but other DM-RS configurations are possible) for channel estimation at the base station. The UE may transmit DM-RS for the physical uplink control channel (PUCCH) and DM-RS for the physical uplink shared channel (PUSCH) . The PUSCH DM-RS may be transmitted in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be transmitted in different configurations depending on whether short or long PUCCHs are transmitted and depending on the particular PUCCH format used. The UE may transmit sounding reference signals (SRS) . The SRS may be transmitted in the last symbol of a subframe. The SRS may have a comb structure, and a UE may transmit SRS on one of the combs. The SRS may be used by a base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

FIG. 2D illustrates an example of various UL channels within a subframe of a frame. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI) , such as scheduling requests, a channel quality indicator (CQI) , a precoding matrix indicator (PMI) , a rank indicator (RI) , and hybrid automatic repeat request (HARQ) acknowledgment (ACK) (HARQ-ACK) feedback (i.e., one or more HARQ ACK bits indicating one or more ACK and/or negative ACK (NACK) ) . The PUSCH carries data, and may additionally be used to carry a buffer status report (B SR) , a power headroom report (PHR) , and/or UCI.

FIG. 3 is a block diagram of a base station 310 in communication with a UE 350 in an access network. In the DL, IP packets from the EPC 160 may be provided to a controller/processor 375. The controller/processor 375 implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller/processor 375 provides RRC layer functionality associated with broadcasting of system information (e.g., MIB, SIBs) , RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release) , inter radio access technology (RAT) mobility, and measurement configuration for UE measurement reporting; PDCP layer functionality associated with header compression /decompression, security (ciphering, deciphering, integrity protection, integrity verification) , and handover support functions; RLC layer functionality associated with the transfer of upper layer packet data units (PDUs) , error correction through ARQ, concatenation, segmentation, and reassembly of RLC service data units (SDUs) , re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs) , demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

The transmit (TX) processor 316 andthe receive (RX) processor 370 implement layer 1 functionality associated with various signal processing functions. Layer 1, which includes a physical (PHY) layer, may include error detection on the transport channels, forward error correction (FEC) coding/decoding of the transport channels, interleaving, rate matching, mapping onto physical channels, modulation/demodulation of physical channels, and MIMO antenna processing. The TX processor 316 handles mapping to signal constellations based on various modulation schemes (e.g., binary phase-shift keying (BPSK) , quadrature phase-shift keying (QPSK) , M-phase-shift keying (M-P SK) , M-quadrature amplitude modulation (M-QAM) ) . The coded and modulated symbols may then be split into parallel streams. Each stream may then be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time and/or frequency domain, and then combined together using an Inverse Fast Fourier Transform (IFFT) to produce a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine the coding and modulation scheme, as well as for spatial processing. The channel estimate maybe derived from a reference signal and/or channel condition feedback transmitted by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318 TX. Each transmitter 318 TX may modulate a radio frequency (RF) carrier with a respective spatial stream for transmission.

At the UE 350, each receiver 354 RX receives a signal through its respective antenna 352. Each receiver 354 RX recovers information modulated onto an RF carrier and provides the information to the receive (RX) processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functionality associated with various signal processing functions. The RX processor 356 may perform spatial processing on the information to recover any spatial streams destined for the UE 350. Ifmultip le spatial streams are destined for the UE 350, they may be combined by the RX processor 356 into a single OFDM symbol stream. The RX processor 356 then converts the OFDM symbol stream from the time-domain to the frequency domain using a Fast Fourier Transform (FFT) . The frequency domain signal comprises a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols on each subcarrier, and the reference signal, are recovered and demodulated by determining the most likely signal constellation points transmitted by the base station 310. These soft decisions may be based on channel estimates computed by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals that were originally transmitted by the base station 310 on the physical channel. The data and control signals are then provided to the controller/processor 359, which implements layer 3 and layer 2 functionality.

The controller/processor 359 can be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer-readable medium. In the UL, the controller/processor 359 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the EPC 160. The controller/processor 359 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

Similar to the functionality descried in connection with the DL transmission by the base station 310, the controller/processor 359 provides RRC layer functionality associated with system information (e.g., MIB, SIBs) acquisition, RRC connections, and measurement reporting; PDCP layer functionality associated with header compression /decompression, and security (ciphering, deciphering, integrity protection, integrity verification) ; RLC layer functionality associated with the transfer of upper layer PDUs, error correction through ARQ, concatenation, segmentation, and reassembly of RLC SDUs, re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functionality associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority handling, and logical channel prioritization.

Channel estimates derived by a channel estimator 358 from a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antenna 352 via separate transmitters 354TX. Each transmitter 354TX may modulate an RF carrier with a respective spatial stream for transmission.

The UL transmission is processed at the base station 310 in a manner similar to that described in connection with the receiver function at the UE 350. Each receiver 318RX receives a signal through its respective antenna 320. Each receiver 318RX recovers information modulated onto an RF carrier and provides the information to a RX processor 370.

The controller/processor 375 can be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer-readable medium. In the UL, the controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 350. IP packets from the controller/processor 375 may be provided to the EPC 160. The controller/processor 375 is also responsible for error detection using an ACK and/or NACK protocol to support HARQ operations.

At least one of the TX processor 368, the RX processor 356, and the controller/processor 359 may be configured to perform aspects in connection with 198 of FIG. 1.

At least one of the TX processor 316, the RX processor 370, and the controller/processor 375 may be configured to perform aspects in connection with 199 of FIG. 1.

5G massive MIMO may be a key enabler for increasing system throughput. With an active antenna unit (AAU) , the antenna ports may be associated with individual RF chains. A high beamforming gain may be achieved with AAUs. However, the use of AAUs may result in a significant increase in power consumption. Passive MIMO may be used as a substitute for AAUs.

FIG. 4A is a diagram illustrating an example wireless communication system 400A. A UE 1 104a may be located in a coverage area of, and may be served by a base station 1 102a/180a. Similarly, a UE 2 104b may be located in a coverage area of, and may be served by a base station 2 102b/180b. Due to the existence of a blockage that significantly obstructs signal propagation, the base station 1 102a/180a may not be able to communicate with the UE 2 104b directly, and similarly, the base station 2 102b/180b may not be able to communicate with the UE 1 104a directly.

FIG. 4B is a diagram illustrating an example wireless communication system 400B. A base station 1 102a/180a may communicate directly with a UE 1 104a. However, due to the existence of a blockage, the base station 1 102a/180a may not communicate directly with a UE 2 104b. ARIS 402 may be employed to extend cellular coverage (e.g., 5G coverage) with negligible power consumption. The RIS 402 may be a near passive device. The RIS 402 may include, or may be associated with a RIS controller (not shown) that is in communication with a base station (e.g., the base station 1 102a/180a) . The base station 1 102a/180a may transmit suitable configure information to the RIS controller to configure the operation of the RIS 402. In particular, the base station 1 102a/180a may configure coefficients associated with the RIS elements of the RIS 402, such that the RIS 402 may reflect an impinging radio wave to a desired direction. Accordingly, through coordination with the UE 2 104b, the base station 1 102a/180a may configure the RIS 402 to reflect impinging downlink signals from the base station 1 102a/180a on a beam toward the UE 2 104b and to reflect impinging uplink signals from the UE 2 104b on abeam toward the base station 1 102a/180a. In other words, by placing the RIS 402 at an appropriate location, the base station 1 102a/180a may communicate with the UE 2 104b via the RIS 402, despite the fact the base station 1 102a/180a may not communicate directly with the UE 2 104b due to the presence of the blockage. In another configuration, the RIS 402 maybe configured by aUE (e.g., the UE2 104b) . ARIS may also be referredto as an intelligent reflective surface (IRS) .

Sidelink communication (which may be D2D communication) may allow two UEs to communicate with each other directly without routing from a base station. The sidelink communication may share the same spectrum (e.g., a licensed spectrum) as other communications in the cellular link (e.g., uplink or downlink) . A sidelink may also be referred to as a PC5 link. One of two resource allocation modes may be used with the sidelink communication. With mode 1 resource allocation, the base station may control the resource allocation over the sidelink to coordinate the interferences among different pairs of sidelink communicating UEs. Alternatively, with mode 2 resource allocation, the UE may autonomously determine resource allocation on its own based on sensing and resource reservation. In particular, in mode 2, the UE may sense the medium, and determine available (free) resources for communication based on the sensing. Such sensing may depend on the activities of other UEs in the vicinity of the sensing UE. In one configuration, the sensing may be based on a measured reference signal received power (RSRP) . For example, ifa UE measures an RSRP on a frequency resource, and determines that the RSRP is higher than a threshold, then the UE may determine that this resource is reserved (i.e., not available/not free) because it will likely be occupied by other UEs in a future transmission. The UE may use resources that are not reserved (i.e., available/free) or are reserved by other UEs that are far away (hence not creating any significant interference among each other) for a subsequent sidelink transmission.

FIG. 5A is a diagram illustrating an example wireless communication system 500A in which sidelink communication may be used. A UE 104a may communicate directly with abase station 102/180 (e.g., via a direct Uu link) . The UE 104a may be located within a coverage area 502 of the base station 102/180. A UE 104b and a UE 104c may communicate with eachother over a sidelink. Both the UE 104b and the UE 104c may be located within the coverage area 502. A UE 104d and a UE 104e may communicate with each other over a sidelink, where at least one of the UE 104d or the UE 104e may be located outside the coverage area 502. For example, the UE 104e may be located outside the coverage area 502 of the base station 102/180, which may not affect the sidelink communication between the UE 104d and the UE 104e.

When a RIS is deployed to assist in the wireless communication, the RIS may be used to control the propagation environment in which the RIS operates. In particular, the reflection matrix of the RIS may be dynamically changed. For a sidelink UE, this may create certain challenges. For example, the operation of the RIS may render the sensing results obtained by a sidelink UE unreliable because the channel strength on a link may be impacted by whether the RIS is on or off. As another example, for two UEs attempting to communicate with each other, the channel quality may experience significant changes over time, making channel state information (CSI) feedback (and possibly power control) less useful. In case of using a RIS in positioning, the positioning accuracymay be a function of whether the RIS is present or not. Herein a present RIS may refer to a RIS that is switched on and may assist in at least some of the communication, and may not refer to a RIS that is switched off for all communication.

FIG. 5B is a diagram illustrating an example wireless communication system 500B in which sidelink communication and a RIS may be used. A UE 104a may communicate directly with a base station 102/180 (e.g., via a direct Uu link) . The UE 104a may be located within a coverage area 502 of the base station 102/180. A UE 104f may communicate with the base station 102/180 via a RIS 504 due to the presence of a blockage between the UE 104f and the base station 102/180. The UE 104f may be located within the coverage area 502. A UE 104d and a UE 104e may communicate with each other over a direct sidelink, where at least one of the UE 104d or the UE 104e may be located outside the coverage area 502. For example, the UE 104e may be located outside the coverage area 502 of the base station 102/180, which may not affectthe sidelink communication between the UE 104d and the UE 104e. Further, a sidelink UE 1 104b and a sidelink UE 2 104c may communicate with each other over a sidelink via the RIS 504 due to the presence of a blockage between the sidelink UE 1 104b and the sidelink UE 2 104c. In one configuration, the sidelink UE 1 104b may be located outside the coverage area 502 of the base station 102/180, which may not affect the sidelink communication between the sidelink UE 1 104b and the sidelink UE 2 104c.

Aspects of the disclosure may relate to the signaling of the presence of a RIS in the communication system. The UEs or other wireless devices may be inside or outside the coverage area of a base station.

FIG. 6A is a diagram of a communication flow 600A associated with a 4-step random access channel (RACH) procedure. First, the base station 102/180 may transmit, to a UE 104, a PSS, an SSS, and a PBCH in an SSB. The base station 102/180 may then transmit, to the UE 104, a SIB 1 (SIB1) via a PDCCH and/or a PDSCH. To begin the 4-step RACH procedure, the UE 104 may transmit, to the base station 102/180, a Message 1 including a physical random access channel (PRACH) preamble via a PRACH. Next, the base station 102/180 may transmit, to the UE 104, a Message 2 (also known as a random access response (RAR) message) including a timing advance, an uplink grant for the Message 3, and a temporary cell -radio network temporary identifier (TC-RNTI) , etc. via a PDCCH and/or a PDSCH. Next, the UE 104 may transmit, to the base station 102/180, a Message 3 including an RRC connection request, a scheduling request, and a buffer status, etc. via a PUSCH. Thereafter, the base station 102/180 may transmit, to the UE 104, a Message 4 including a contention resolution message via a PDCCH and/or a PDSCH.

FIG. 6B is a diagram of a communication flow 600B associated with a 2-step RACH procedure. The 2-step RACH procedure may be used in a number of scenarios. For example, the 2-step RACH procedure may be used when the UE transitions from an RRC Idle/Inactive state to an RRC Connected state. The 2-step RACH procedure may be used for a small data transmission when the UE is in an RRC Idle/Inactive state. The 2-step RACH procedure may be used for a handover of a UE from a source cell to a target cell when the UE is in an RRC Connected state. The 2-step RACH procedure may also be used when a UE attempts to recover from an uplink synchronization loss when the UE is in an RRC Connected state. First, the base station 102/180 may transmit, to an RRC Connected UE 104, an SSB, a SIB, at least one reference signal, and/or RRC signaling. The UE 104 may then perform downlink synchronization and system information decoding and measurement. To begin the 2-step RACH procedure, in step 1, the UE 104 may transmit, to the base station 102/180, a Message A (also known as a random access message) via a PRACH (for the Message A preamble) and a PUSCH (for the Message A payload) . The Message A payload may include similar information as the Message 3 in a 4-step PRACH procedure. For example, the Message A payload may include an RRC request and a buffer state report, etc. The Message A payload may also include some small data. The base station 102/180 mayprocess and attempt to decode the MessageA preamble. Once the Message A preamble is decoded, the base station 102/180 may process the Message A payload. Next, in step 2, the base station 102/180 may transmit, to the UE 104, a Message B (also known as an RAR message) via a PDCCH and/or a PDSCH. The Message B may include similar information as the Message 2 as well as the Message 4 of the 4-step RACH procedure. Thereafter, upon successfully receiving the message B, the UE 104 may transmit, to the base station 102/180, a HARQ-ACK feedback message corresponding to the Message B via a PUCCH.

FIG. 7 is a diagram 700 illustrating a structure of a sidelink SSB (S-SSB) . The S-SSB bandwidth may correspond to 11 PRBs, and may include physical sidelink broadcast channels (PS-BCHs) , sidelink PSSs (S-PSSs) , and sidelink SSSs (S-SSSs) . The PS-BCHs may be associated with 11 PRBs and 9/7 OFDM symbols for the normal CP (NCP) /extended CP (ECP) . The first PS-BCH symbol may be used for automatic gain control (AGC) training at the receiver. An S-PSS may be a length 127 M-sequence, and may be associated with the same generator/initial value as a Uu PSS with cyclic shifts (CSs) {22, 65} , which may be repeated on 2 consecutive symbols. An S-SSS may be length 127 Gold sequence, and may be associated with the same generator/initial value and cyclic shifts as a Uu SSS, which may be repeated on 2 consecutive symbols. A demodulation reference signal (DMRS) may be provided in every PS-BCH symbol on every fourth RE. A PS-BCH may be associated with a 56-bit payload, within which a direct frame number (DFN) may take up 10 bits, an indication of the TDD configuration may take up 12 bits, a slot index may take up 7 bits, an in-coverage indicator may take up 1 bit, reserve bits may take up 2 bits, and a cyclic redundancy check (CRC) code may take up 24 bits. The TDD configuration may be associated with system wide information, (e.g., a TDD uplink-downlink common configuration and/or potential sidelink slots) .

FIG. 8 is a diagram of a communication flow 800 of a method of wireless communication. At 808, the base station 802 may identify whether at least one RIS is present in a coverage area of the base station 802. At 810, the base station 802 may transmit to a UE A 804, and the UE A 804 may receive from the base station 802, a first indication of whether the at least one RIS is present in the coverage area.

In one configuration, the first indication 810 may be transmitted and received via or associated with at least one of a MIB via a PBCH, a DMRS configuration associated with the PBCH, a sequence associated with a PSS, or a sequence associated with an SSS.

In one configuration, whether the at least one RIS is present in the coverage area may be indicated by the base station 802 in a MIB via a PBCH (e.g., with 1 bit) . In one configuration, whether the at least one RIS is present in the coverage area may be indicated by the base station 802 based on a DMRS configuration associated with the PBCH (e.g., a configuration type I may indicate at least one RIS is present) . In one configuration, whether the at least one RIS is present in the coverage area may be indicated by the base station 802 based on a sequence associated with a PSS (e.g., some of the possible sequences for the PSS may be used to indicate the presence of at least one RIS, while other possible sequences for the PSS maybe used to indicate the absence of any RIS) . In one configuration, whether the at least one RIS is present in the coverage area may be indicated by the base station 802 based on a sequence associated with an SSS (e.g., some of the possible sequences for the SSS may be used to indicate the presence of at least one RIS, while other possible sequences for the SSS may be used to indicate the absence of any RIS) . In one configuration, whether the at least one RIS is present in the coverage area may be indicated by the base station 802 based on, jointly, a sequence associated with a PSS and a sequence associated with an SSS (i.e., a combination of a sequence associated with a PSS and a sequence associated with an SSS) (e.g., some sequence combinations of possible sequence combinations for the PSS and the SSS may be used to indicate the presence of at least one RIS, while other possible sequence combinations may be used to indicate the absence of any RIS) .

In one configuration, the first indication 810 may be transmitted and received via at least one of a PDSCH associated with a SIB1, a DMRS associated with the PDSCH associated with the SIB1, a DCI message via a PDCCH associated with the SIB1, or a DMRS associated with the PDCCH associated with the SIB1.

In one configuration, whether the at least one RIS is present in the coverage area may be indicated by the base station 802 via a PDSCH associated with a SIB1. In one configuration, whether the at least one RIS is present in the coverage area may be indicated by the base station 802 based on a DMRS associated with the PDSCH associated with the SIB1 (e.g., a particular DMRS sequence may be used to indicate the presence of at least one RIS, while a different DMRS sequence may be used to indicate the absence of any RIS) . In one configuration, whether the at least one RIS is present in the coverage area may be indicated by the base station 802 in a DCI message via a PDCCH associated with the SIB1. In one configuration, whether the at least one RIS is present in the coverage area may be indicated by the base station 802 based on a DMRS associated with the PDCCH associated with the SIB1.

In one configuration, the first indication 810 may be transmitted and received via at least one of a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.

In one configuration, whether the at least one RIS is present in the coverage area may be indicated by the base station 802 in a Message 2 (i.e., the RAR message) (e.g., in a DCI message via a PDCCH and/or via a PDSCH) in a 4-step RACH procedure. In one configuration, whether the at least one RIS is present in the coverage area maybe indicated by the base station 802 in a Message4 (e.g., in a DCI message via aPDCCH and/or via a PDSCH) in the 4-step RACH procedure. In one configuration, whether the at least one RIS is present in the coverage area maybe indicated by the base station 802 in a Message B (e.g., in a DCI message via a PDCCH and/or via a PDSCH) in a 2-step RACH procedure.

In one configuration, the first indication 810 may be transmitted and received via at least one of RRC signaling or a MAC -control element (CE) (MAC-CE) .

In one configuration, whether the at least one RIS is present in the coverage area may be indicated by the base station 802 via RRC signaling. In one configuration, whether the at least one RIS is present in the coverage areamaybe indicated by the base station 802 in a MAC-CE.

In case at least one RIS is present, at 812, the base station 802 may transmit, to the UE A 804, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS. The communication directions associated with the operation of the at least one RIS may indicate, e.g., whether the at least one RIS would assist in the uplink, the downlink, or both. In one configuration, the second indication of one or more communication directions associated with the operation of the at least one RIS may take up at least 2 bits (e.g., “00” may indicate that the RIS may assist in the downlink, “01” may indicate that the RIS may assist in the uplink, and “10” may indicate that the RIS may assist in both the downlink and the uplink) .

The time division pattern associated with the operation of the at least one RIS may be on a per symbol, per sub-slot, or per slot basis, and may indicate whether the at least one RIS may assist in any particular symbol, sub-slot, or slot. In one configuration, the time division patternmay correspond to abitmap. For example, ifthe system TDD configuration corresponds to a cyclic “DDDUUUD” TDD pattern, and the RIS assists in the downlink and not in the uplink, a 4-bit bitmap may be used to indicate in which of the 4 downlink symbols/sub-slots/slots within the system TDD pattern the RIS may actually assist. In another example with the same system TDD configuration, if the RIS assists in both the downlink and the uplink, a 7-bit bitmap maybe usedto indicate in which symbols/sub-slots/slots within the system TDD pattern the RIS may actually assist. In another configuration, the time division pattern may correspond to a start and length indicator value (SLiV) , which may include the starting symbol/sub-slot/slot and the length of the duration during which the RIS may actually assist, In one configuration, if multiple RISs are present, the time division pattern may be indicated individually for the RISs, where each of the multiple RISs may be associated with a RIS identifier (ID) and an individual time division pattern, In one configuration, if multiple RISs are present, the time division pattern may be collectively indicated, In other words, if at least one RIS would assist in a particular symbol/sub-slot/slot, the time division pattern may indicate that the RISs would assist in the symbol/sub-slot/slot; on the other hand, if none of the RISs would assist in a particular symbol/sub-slot/slot, the time division pattern may indicate that the RISs would not assist in the symbol/sub-slot/slot. In one configuration, separate time division patterns associated with the operation of the at least one RIS may be provided for the Uu link and for the sidelink. It should be appreciated that while a RIS may assist in the uplink, the downlink, or both for the Uu link, the sidelink may be symmetric, and the RIS may not distinguish between communication directions for the sidelink.

In one configuration, the at least one of the second indication or the third indication 812 may be transmitted and received via at least one of a MIB via a PBCH, a PDSCH associated with a SIB1, a DCI message via a PDCCH associated with the SIB1, a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.

In one configuration, the communication directions associated with the operation of the at least one RIS and/or the time division pattern associated with the operation of the at least one RIS may be indicated by the base station 802 in a MIB via a PBCH (e.g., 2 bits may be used to indicate the communication directions, and k bits may be used to indicate the time division pattern) .

In one configuration, the communication directions associated with the operation of the at least one RIS and/or the time division pattern associated with the operation of the at least one RIS may be indicated by the base station 802 via a PDSCH associated with a SIB1 and/or in a DCI message via a PDCCH associated with the SIB1 (e.g., 2 bits may be used to indicate the communication directions, and k bits may be used to indicate the time division pattern) .

In one configuration, the communication directions associated with the operation of the at least one RIS and/or the time division pattern associated with the operation of the at least one RIS may be indicated by the base station 802 in a Message 2 (i.e., the RAR message) (e.g., in a DCI message via a PDCCH and/or via a PDSCH) in a 4-step RACH procedure (e.g., 2 bits may be used to indicate the communication directions, and k bits may be used to indicate the time division pattern) .

In one configuration, the communication directions associated with the operation of the at least one RIS and/or the time division pattern associated with the operation of the at least one RIS may be indicated by the base station 802 in a Message 4 (e.g., in a DCI message via a PDCCH and/or via a PDSCH) in a 4-step RACH procedure (e.g., 2 bits may be used to indicate the communication directions, and k bits may be used to indicate the time division pattern) .

In one configuration, the communication directions associated with the operation of the at least one RIS and/or the time division pattern associated with the operation of the at least one RIS may be indicated by the base station 802 in a Message B (e.g., in a DCI message via a PDCCH and/or via a PDSCH) in a 2-step RACH procedure (e.g., 2 bits may be used to indicate the communication directions, and k bits may be used to indicate the time division pattern) .

In one configuration, the communication directions associated with the operation of the at least one RIS and/or the time division pattern associated with the operation of the at least one RIS may be indicated by the base station 802 based on a combination of the above-described options, where the bits for the indications may be divided and conveyed separately based on a combination of the options (e.g., some of the bits may be conveyed in the MIB, and some of the bits may be conveyed in the SIB1, etc. )

In one configuration, the at least one of the second indication or the third indication 812 may be transmitted and received via at least one of RRC signaling or a MAC-CE.

In one configuration, the communication directions associated with the operation of the at least one RIS and/or the time division pattern associated with the operation of the at least one RIS may be indicated by the base station 802 via RRC signaling.

In one configuration, the communication directions associated with the operation of the at least one RIS and/or the time division pattern associated with the operation of the at least one RIS may be indicated by the base station 802 in a MAC-CE.

The UE A 804 may forward the first indication, the second indication, and/or the third indication to the UE B 806 via a sidelink. In one configuration, the UE B 806 may be outside the coverage area of the base station 802, and may not be able to receive the indications directly from the base station 802. In one configuration, the UE B 806 may be inside the coverage area of the base station 802.

At 814, the UE A 804 may transmit to the UE B 806, and the UE B 806 may receive from the UE A 804, a fourth indication of whether the at least one RIS is present in the coverage area based on the first indication 810. In case at least one RIS is present, at 816, the UE A 804 may transmit to the UE B 806, and the UE B 806 may receive from the UE A 804, at least one of a fifth indication of the one or more communication directions associated with the operation of the at least one RIS or a sixth indication of the at least one time division pattern associated with the operation of the at least one RIS based on the at least one of the second indication or the third indication 812.

In one configuration, the fourth indication, the fifth indication, and/or the sixth indication may be transmitted and received via at least one of a PBCH (e.g., a PS-BCH) , PC5-RRC signaling, or a MAC-CE.

In one configuration, the UE A 804 (which may transmit an S-SSB) may transmit the fourth indication to the UE B 806 via a PBCH (e.g., a PS-BCH) . In one configuration, the UE A 804 may transmit the fifth indication and/or the sixth indication to the UE B 806 via a PBCH (e.g., a PS-BCH) .

In one configuration, the UE A 804 may transmit the fourth indication, the fifth indication, and/or the sixth indication to the UE B 806 via PC5-RRC signaling, In one configuration, the UE A 804 may transmit the fourth indication, the fifth indication, and/or the sixth indication to the UE B 806 in a MAC-CE.

In one configuration, separate time division patterns associated with the operation of the at least one RIS may be provided for the Uu link and for the sidelink, It should be appreciated that while a RIS may assist in the uplink, the downlink, or both for the Uu link, the sidelink may be symmetric, and the RIS may not distinguish between communication directions for the sidelink.

In one configuration, for the sidelink, the base station 802 may signal the presence of at least one RIS and the time division pattern within a particular resource pool. This may be especially useful if the RIS is able to control the frequency response per resource pool. In one configuration, the base station 802 may signal the presence of at least one RIS and the time division pattern across all resource pools. This may be useful if the RIS is not able to control the frequency response per resource pool. In one configuration, the base station 802 may further signal that the RIS is not able to control the frequency response per resource pool. The presence of at least one RIS and the time division pattern within a particular resource pool or across all resource pools may be signaled by the base station 802 (e.g., to the in-coverage UE A 804) via RRC signaling and/or in a MAC-CE. The UE A 804 may relay the indications of these resource pool configurations to one or more out-of-coverage UEs (e.g., the UE B 806) .

At 818, the UE A 804 may communicate with the base station 802 or another UE based on the first indication.

FIG. 9 is a flowchart 900 of a method of wireless communication. The method may be performed by a first UE (e.g., the UE 104/350; the UE A 804; the UE B 806; the apparatus 1302) . The first UE may correspond to either the UE A 804 in FIG. 8 or the UE B 806 in FIG. 8. When the first UE corresponds to the UE A 804, the UE B 806 may be referred to as a third UE. When the first UE corresponds to the UE B 806, the UE A 804 may be referred to as a second UE. At 902, the first UE may receive, from a base station or a second UE, a first indication of whether at least one RIS is present in a coverage area of the base station. For example, 902 may be performed by the RIS management component 1340 in FIG. 13. Referring to FIG. 8, in one aspect, at 810, the first UE (UE A) 804 may receive, from a base station 802, a first indication of whether at least one RIS is present in a coverage area of the base station. In another aspect, at 814, the first UE (UE B) 806 may receive, from a second UE (UE A) 804, a first indication of whether at least one RIS is present in a coverage area of the base station.

At 904, the first UE may communicate with the base station or another UE based on the first indication. For example, 904 may be performed by the RIS management component 1340 in FIG. 13. Referring to FIG. 8, at 818, the first UE (UE A) 804 may communicate with the base station 802 or another UE based on the first indication.

FIG. 10 is a flowchart 1000 of a method of wireless communication. The method may be performed by a first UE (e.g., the UE 104/350; the UE A 804; the UE B 806; the apparatus 1302) . The first UE may correspond to either the UE A 804 in FIG. 8 or the UE B 806 in FIG. 8. When the first UE corresponds to the UE A 804, the UE B 806 maybe referredto as a third UE. When the first UE corresponds to the UE B 806, the UE A 804 may be referred to as a second UE. At 1002, the first UE may receive, from a base station or a second UE, a first indication of whether at least one RIS is present in a coverage area of the base station. For example, 1002 may be performed by the RIS management component 1340 in FIG. 13. Referring to FIG. 8, in one aspect, at 810, the first UE (UE A) 804 may receive, from a base station 802, a first indication of whether at least one RIS is present in a coverage area of the base station. In another aspect, at 814, the first UE (UE B) 806 may receive, from a second UE (UE A) 804, a first indication of whether at least one RIS is present in a coverage area of the base station.

At 1012, the first UE may communicate with the base station or another UE based on the first indication. For example, 1012 may be performed by the RIS management component 1340 in FIG. 13. Referring to FIG. 8, at 818, the first UE (UE A) 804 may communicate with the base station 802 or another UE based on the first indication.

In one configuration, referring back to FIG. 8, the first indication 810 may be received from the base station 802.

In one configuration, referring backto FIG. 8, the first indication 810 maybe received via or associated with at least one of a MIB via a PBCH, a DMRS configuration associated with the PBCH, a sequence associated with a PSS, or a sequence associated with an SSS.

In one configuration, referring back to FIG. 8, the first indication 810 may be received via at least one of a PDSCH associated with a SIB1, a DMRS associated with the PDSCH associated with the SIB1, a DCI message via a PDCCH associated with the SIB1, or a DMRS associated with the PDCCH associated with the SIB1.

In one configuration, referring back to FIG. 8, the first indication 810 may be received via at least one of a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.

In one configuration, referring back to FIG. 8, the first indication 810 may be received via at least one of RRC signaling or a MAC-CE.

In one configuration, at 1006, the first UE may transmit, to a third UE, a fourth indication of whether the at least one RIS is present in the coverage area based on the first indication. For example, 1006 may be performed by the RIS management component 1340 in FIG. 13. Referring to FIG. 8, at 814, the first UE (UE A) 804 may transmit, to a third UE (UE B) 806, a fourth indication of whether the at least one RIS is present in the coverage area based on the first indication 810.

In one configuration, referring back to FIG. 8, the fourth indication 814 may be transmitted via a PBCH.

In one configuration, the at least one RIS may be present in the coverage area. At 1004, the first UE may receive, from the base station, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS. For example, 1004 may be performed by the RIS management component 1340 in FIG. 13. Referring to FIG. 8, at 812, the first UE (UE A) 804 may receive, from the base station 802, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS.

In one configuration, referring back to FIG. 8, the at least one of the second indication or the third indication 812 may be received via at least one of a MIB via a PBCH, a PDSCH associated with a SIB1, a DCI message via a PDCCH associated with the SIB1, a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.

In one configuration, referring back to FIG. 8, the at least one of the second indication or the third indication 812 may be received via at least one of RRC signaling or a MAC-CE.

In one configuration, the operation of the at least one RIS may be associated with at least one resource pool.

In one configuration, at 1008, the first UE may transmit, to a third UE, at least one of a fifth indication of the one or more communication directions associated with the operation of the at least one RIS or a sixth indication of the at least one time division pattern associated with the operation of the at least one RIS based on the at least one of the second indication or the third indication. For example, 1008 may be performed by the RIS management component 1340 in FIG. 13. Referring to FIG. 8, at 816, the first UE (UE A) 804 may transmit, to a third UE (UE B) 806, at least one of a fifth indication of the one or more communication directions associated with the operation of the at least one RIS or a sixth indication of the at least one time division pattern associated with the operation of the at least one RIS based on the at least one of the second indication or the third indication 812.

In one configuration, referring back to FIG. 8, the at least one of the fifth indication or the sixth indication 816 may be transmitted via at least one of a PBCH, PC5-RRC signaling, or a MAC-CE.

In one configuration, referring back to FIG. 8, the first indication may be received from the second UE (UE A) 804.

In one configuration, referring back to FIG. 8, the first UE (UE B) 806 may be outside the coverage area of the base station.

In one configuration, referring back to FIG. 8, the first indication 814 may be received via a PBCH.

In one configuration, the at least one RIS may be present in the coverage area. At 1010, the first UE may receive, from the second UE, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS. For example, 1010 may be performed by the RIS management component 1340 in FIG. 13. Referring to FIG. 8, at 816, the first UE (UE B) 806 may receive, from the second UE (UE A) 804, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS.

In one configuration, referring back to FIG. 8, the at least one of the second indication or the third indication 816 may be received via at least one of a PBCH, PC5-RRC signaling, or a MAC-CE.

FIG. 11 is a flowchart 1100 of a method of wireless communication. The method may be performed by a base station (e.g., the base station 102/180/310/802; the apparatus 1402) . At 1102, the base station may identify whether at least one RIS is present in a coverage area of the base station. For example, 1102 may be performed by the RIS management component 1440 in FIG. 14. Referring to FIG. 8, at 808, the base station 802 may identify whether at least one RIS is present in a coverage area of the base station 802.

At 1104, the base station may transmit, to a UE, a first indication of whether the at least one RIS is present in the coverage area. For example, 1104 may be performed by the RIS management component 1440 in FIG. 14. Referring to FIG. 8, at 810, the base station 802 may transmit, to a UE 804, a first indication of whether the at least one RIS is present in the coverage area.

FIG. 12 is a flowchart 1200 of a method of wireless communication. The method may be performed by a base station (e.g., the base station 102/180/310/802; the apparatus 1402) . At 1202, the base station may identify whether at least one RIS is present in a coverage area of the base station. For example, 1202 may be performed by the RIS management component 1440 in FIG. 14. Referring to FIG. 8, at 808, the base station 802 may identify whether at least one RIS is present in a coverage area of the base station 802.

At 1204, the base station may transmit, to a UE, a first indication of whether the at least one RIS is present in the coverage area. For example, 1204 may be performed by the RIS management component 1440 in FIG. 14. Referring to FIG. 8, at 810, the base station 802 may transmit, to a UE 804, a first indication of whether the at least one RIS is present in the coverage area.

In one configuration, referring back to FIG. 8, the first indication 810 may be transmitted via or associated with at least one of a MIB via a PBCH, a DMRS configuration associated with the PBCH, a sequence associated with a PSS, or a sequence associated with an SSS.

In one configuration, referring back to FIG. 8, the first indication 810 may be transmitted via at least one of a PDSCH associated with a SIB1, a DMRS associated with the PDSCH associated with the SIB1, a DCI message via a PDCCH associated with the SIB1, or a DMRS associated with the PDCCH associated with the SIB1.

In one configuration, referring back to FIG. 8, the first indication 810 may be transmitted via at least one of a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.

In one configuration, referring back to FIG. 8, the first indication 810 may be transmitted via at least one of RRC signaling or a MAC-CE.

In one configuration, the at least one RIS may be present in the coverage area. At 1206, the base station may transmit, to the UE, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS. The at least one time division pattern may include a first time division pattern associated with a Uu link or a second time division pattern associated with a sidelink. For example, 1206 may be performed by the RIS management component 1440 in FIG. 14. Referring to FIG. 8, at 812, the base station 802 may transmit, to the UE 804, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS.

In one configuration, referring back to FIG. 8, the at least one of the second indication or the third indication 812 may be transmitted via at least one of a MIB via a PBCH, a PDSCH associated with a SIB1, a DCI message via a PDCCH associated with the SIB1, a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.

In one configuration, referring back to FIG. 8, the at least one of the second indication or the third indication 812 may be transmitted via at least one of RRC signaling or a MAC-CE.

FIG. 13 is a diagram 1300 illustrating an example of a hardware implementation for an apparatus 1302. The apparatus 1302 may be a UE, a component of a UE, or may implement UE functionality. In some aspects, the apparatusl302 may include a cellular baseband processor 1304 (also referred to as a modem) coupled to a cellular RF transceiver 1322. In some aspects, the apparatus 1302 may further include one or more subscriber identity modules (SIM) cards 1320, an application processor 1306 coupled to a secure digital (SD) card 1308 and a screen 1310, a Bluetooth module 1312, a wireless local area network (WLAN) module 1314, a Global Positioning System (GPS) module 1316, or a power supply 1318. The cellular baseband processor 1304 communicates through the cellular RF transceiver 1322 with the UE 104 and/or BS 102/180. The cellular baseband processor 1304 may include a computer-readable medium /memory. The computer-readable medium /memory may be non-transitory. The cellular baseband processor 1304 is responsible for general processing, including the execution of software stored on the computer-readable medium /memory. The software, when executed by the cellular baseband processor 1304, causes the cellular baseband processor 1304 to perform the various functions described supra. The computer-readable medium /memory may also be used for storing data that is manipulated by the cellular baseband processor 1304 when executing software. The cellular baseband processor 1304 further includes a reception component 1330, a communication manager 1332, and a transmission component 1334. The communication manager 1332 includes the one or more illustrated components. The components within the communication manager 1332 may be stored in the computer-readable medium /memory and/or configured as hardware within the cellular baseband processor 1304. The cellular baseband processor 1304 may be a component of the UE 350 and may include the memory 360 and/or at least one of the TX processor 368, the RX processor 356, and the controller/processor 359. In one configuration, the apparatus 1302 may be a modem chip and include just the baseband processor 1304, and in another configuration, the apparatus 1302 may be the entire UE (e.g., see 350 of FIG. 3) and include the additional modules of the apparatus 1302.

The communication manager 1332 includes a RIS management component 1340 that may be configured to receive, from a base station or a second UE, a first indication of whether at least one RIS is present in a coverage area of the base station, e.g., as described in connection with 902 in FIG. 9 and 1002 in FIG. 10. The RIS management component 1340 may be configured to receive, from the base station, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS, e.g., as described in connection with 1004 in FIG. 10. The RIS management component 1340 may be configured to transmit, to a third UE, a fourth indication of whether the at least one RIS is present in the coverage area based on the first indication, e.g., as descried in connection with 1006 in FIG. 10. The RIS management component 1340 may be configured to transmit, to a third UE, at least one of a fifth indication of the one or more communication directions associated with the operation of the at least one RIS or a sixth indication of the at least one time division pattern associated with the operation of the at least one RIS based on the at least one of the second indication or the third indication, e.g., as descried in connection with 1008 in FIG. 10. The RIS management component 1340 may be configured to receive, from the second UE, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS, e.g., as descried in connection with 1010 in FIG. 10. The RIS management component 1340 may be configured to communicate with the base station or another UE based on the first indication, e.g., as descried in connection with 904 in FIG. 9 and 1012 in FIG. 10.

The apparatus may include additional components that perform each of the blocks of the algorithm in the flowcharts of FIGs. 8-10. As such, each block in the flowcharts of FIGs. 8-10 may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

As shown, the apparatus 1302 may include a variety of components configured for various functions. In one configuration, the apparatus 1302, and in particular the cellular baseband processor 1304, includes means for receiving, from a base station or a second UE, a first indication of whether at least one RIS is present in a coverage area of the base station. The apparatus 1302, and in particular the cellular baseband processor 1304, includes means for communicating with the base station or another UE based on the first indication.

In one configuration, the first indication may be received from the base station. In one configuration, the first indication may be received via or associated with at least one of a MIB via a PBCH, a DMRS configuration associated with the PBCH, a sequence associated with a PSS, or a sequence associated with an SSS. In one configuration, the first indication may be received via at least one of a PDSCH associated with a SIB1, a DMRS associated with the PDSCH associated with the SIB1, a DCI message via a PDCCH associated with the SIB1, or a DMRS associated with the PDCCH associated with the SIB1. In one configuration, the first indication may be received via at least one of a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure. In one configuration, the first indication may be received via at least one of RRC signaling or a MAC-CE. In one configuration, the apparatus 1302, and in particular the cellular baseband processor 1304, includes means for transmitting, to a third UE, a fourth indication of whether the at least one RIS is present in the coverage area based on the first indication. In one configuration, the fourth indication may be transmitted via a PBCH. In one configuration, the at least one RIS may be present in the coverage area. The apparatus 1302, and in particular the cellular baseband processor 1304, includes means for receiving, from the base station, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS. In one configuration, the at least one of the second indication or the third indication may be received via atleast one of a MIB via a PBCH, a PDSCH associated with a SIB1, a DCI message via a PDCCH associated with the SIB1, a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure. In one configuration, the at least one of the second indication or the third indication maybe received via at least one of RRC signaling or a MAC-CE. In one configuration, the operation of the at least one RIS may be associated with at least one resource pool. In one configuration, the apparatus 1302, and in particular the cellular baseband processor 1304, includes means for transmitting, to a third UE, at least one of a fifth indication of the one or more communication directions associated with the operation of the at least one RIS or a sixth indication of the at least one time division pattern associated with the operation of the at least one RIS based on the at least one of the second indication or the third indication. In one configuration, the at least one of the fifth indication or the sixth indication may be transmitted via at least one of a PBCH, PC5-RRC signaling, or a MAC-CE. In one configuration, the first indication may be received from the second UE.In one configuration, the first UE may be outside the coverage area of the base station. In one configuration, the first indication may be received via a PBCH. In one configuration, the at least one RIS may be present in the coverage area. The apparatus 1302, and in particular the cellular baseband processor 1304, includes means for receiving, from the second UE, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS. In one configuration, the at least one of the second indication or the third indication may be received via at least one of a PBCH, PC5-RRC signaling, or a MAC-CE.

The means may be one or more of the components of the apparatus 1302 configured to perform the functions recited by the means. As described supra, the apparatus 1302 may include the TX Processor 368, the RX Processor 356, and the controller/processor 359. As such, in one configuration, the means may be the TX Processor 368, the RX Processor 356, and the controller/processor 359 configured to perform the functions recited by the means.

FIG. 14 is a diagram 1400 illustrating an example of a hardware implementation for an apparatus 1402. The apparatus 1402 may be a base station, a component of a base station, or may implement base station functionality. In some aspects, the apparatus 1302 may include a baseband unit 1404. The baseband unit 1404 may communicate through a cellular RF transceiver 1422 with the UE 104. The baseband unit 1404 may include a computer-readable medium /memory. The baseband unit 1404 is responsible for general processing, including the execution of software stored on the computer-readable medium /memory. The software, when executed by the baseband unit 1404, causes the baseband unit 1404 to perform the various functions described supra. The computer-readable medium /memory may also be used for storing data that is manipulated by the baseband unit 1404 when executing software. The baseband unit 1404 further includes a reception component 1430, a communication manager 1432, and a transmission component 1434. The communication manager 1432 includes the one or more illustrated components. The components within the communication manager 1432 may be stored in the computer-readable medium /memory and/or configured as hardware within the baseband unit 1404. The baseband unit 1404 may be a component of the base station 310 and may include the memory 376 and/or at least one of the TX processor 316, the RX processor 370, and the controller/processor 375.

The communication manager 1432 includes a RIS management component 1440 that may be configured to identify whether at least one RIS is present in a coverage area of the base station, e.g., as described in connection with 1102 in FIG. 11 and 1202 in FIG. 12. The RIS management component 1440 may be configured to transmit, to a UE, a first indication of whether the at least one RIS is present in the coverage area, e.g., as descried in connection with 1104 in FIG. 11 and 1204 in FIG. 12. The RIS management component 1440 may be configured to transmit, to the UE, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS, e.g., as descried in connection with 1206 in FIG. 12.

The apparatus may include additional components that perform each of the blocks of the algorithm in the flowcharts of FIGs. 8, 11, and 12. As such, each block in the flowcharts of FIGs. 8, 11, and 12 may be performed by a component and the apparatus may include one or more of those components. The components may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by a processor configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by a processor, or some combination thereof.

As shown, the apparatus 1402 may include a variety of components configured for various functions. In one configuration, the apparatus 1402, and in particular the baseband unit 1404, includes means for identifying whether at least one RIS is present in a coverage area of the base station. The apparatus 1402, and in particular the baseband unit 1404, includes means for transmitting, to a UE, a first indication of whether the at least one RIS is present in the coverage area.

In one configuration, the first indication may be transmitted via or associated with at least one of a MIB via a PBCH, a DMRS configuration associated with the PBCH, a sequence associated with a PSS, or a sequence associated with an SSS. In one configuration, the first indication may be transmitted via at least one of a PDSCH associated with a SIB1, a DMRS associated with the PDSCH associated with the SIB1, a DCI message via a PDCCH associated with the SIB1, or a DMRS associated with the PDCCH associated with the SIB1. In one configuration, the first indication may be transmitted via at least one of a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure. In one configuration, the first indication may be transmitted via at least one of RRC signaling or a MAC-CE. In one configuration, the at least one RIS may be present in the coverage area. The apparatus 1402, and in particular the baseband unit 1404, includes means for transmitting, to the UE, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS. In one configuration, the at least one of the second indication or the third indication may be transmitted via at least one of a MIB via a PBCH, a PDSCH associated with a SIB1, a DCI message via a PDCCH associated with the SIB1, a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure. In one configuration, the at least one of the second indication or the third indication may be transmitted via atleast one of RRC signaling or a MAC-CE. In one configuration, the operation of the at least one RIS may be associated with at least one resource pool.

The means may be one or more of the components of the apparatus 1402 configured to perform the functions recited by the means. As described supra, the apparatus 1402 may include the TX Processor 316, the RX Processor 370, and the controller/processor 375. As such, in one configuration, the means may be the TX Processor 316, the RX Processor 370, and the controller/processor 375 configured to perform the functions recited by the means.

Referring back to FIGs. 8-12, a base station may identify whether at least one RIS is present in a coverage area of the base station. The base station may transmit to a UE, and the UE may receive from the base station, a first indication of whether the at least one RIS is present in the coverage area. When at least one RIS is present, the base station may further transmit to the UE, and the UE may further receive from the base station, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS. The UE may forward the indications associated with the at least one RIS to additional UEs via a sidelink. The additional UEs may be outside the coverage area of the base station. Accordingly, the UEs (especially sidelink UEs) may operate with suitable knowledge about the presence or absence of RISs and about other RIS configuration information if at least one RIS is present.

It is understood that the specific order or hierarchy of blocks in the processes /flowcharts disclosed is an illustration of example approaches. Based upon design preferences, it is understood that the specific order or hierarchy of blocks in the processes /flowcharts may be rearranged. Further, some blocks may be combined or omitted. The accompanying method claims present elements of the various blocks in a sample order, and are not meant to be limited to the specific order or hierarchy presented.

The previous description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not intended to be limited to the aspects shown herein, but is to be accorded the full scope consistent with the language claims, wherein reference to an element in the singular is not intended to mean “one and only one” unless specifically so stated, but rather “one or more. ” Terms such as “if, ” “when, ” and “while” should be interpreted to mean “under the condition that” rather than imply an immediate temporal relationship or reaction. That is, these phrases, e.g., “when, ” do not imply an immediate action in response to or during the occurrence of an action, but simply imply that if a condition is met then an action will occur, but without requiring a specific or immediate time constraint for the action to occur. The word “exemplary” is used herein to mean “serving as an example, instance, or illustration. ” Any aspect descried herein as “exemplary” is not necessarily to be construed as preferred or advantageous over other aspects. Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” include any combination of A, B, and/or C, and may include multiples of A, multiples of B, or multiples of C. Specifically, combinations such as “at least one of A, B, or C, ” “one or more of A, B, or C, ” “at least one of A, B, and C, ” “one or more of A, B, and C, ” and “A, B, C, or any combination thereof” may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, where any such combinations may contain one or more member or members of A, B, or C. All structural and functional equivalents to the elements of the various aspects descried throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are intended to be encompassed by the claims. Moreover, nothing disclosed herein is intended to be dedicated to the public regardless of whether such disclosure is explicitly recited in the claims. The words “module, ” “mechanism, ” “element, ” “device, ” and the like may not be a substitute for the word “means. ” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for. ”

The following aspects are illustrative only and may be combined with other aspects or teachings descried herein, without limitation.

Aspect 1 is an apparatus for wireless communication at a first UE including at least one processor coupled to a memory and configured to receive, from a base station or a second UE, a first indication of whether at least one RIS is present in a coverage area of the base station; and communicate with the base station or another UE based on the first indication.

Aspect 2 is the apparatus of aspect 1, where the first indication is received from the base station.

Aspect 3 is the apparatus of aspect 2, where the first indication is received via or associated with at least one of a MIB via a PBCH, a DMRS configuration associated with the PBCH, a sequence associated with a PSS, or a sequence associated with an SSS.

Aspect 4 is the apparatus of aspect 2, where the first indication is received via at least one of a PDSCH associated with a SIB1, a DMRS associated with the PDSCH associated with the SIB1, a DCI message via a PDCCH associated with the SIB1, or a DMRS associated with the PDCCH associated with the SIB1.

Aspect 5 is the apparatus of aspect2, where the first indication is received via at least one of a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.

Aspect 6 is the apparatus of aspect 2, where the first indication is received via at least one of RRC signaling or a MAC-CE.

Aspect 7 is the apparatus of any of aspects 2 to 6, the at least one processor being further configured to: transmit, to a third UE, a fourth indication of whether the at least one RIS is present in the coverage area based on the first indication.

Aspect 8 is the apparatus of aspect 7, where the fourth indication is transmitted via a PBCH.

Aspect 9 is the apparatus of any of aspects 2 to 8, where the at least one RIS is present in the coverage area, and the at least one processor is further configured to: receive, from the base station, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS.

Aspect 10 is the apparatus of aspect 9, where the at least one of the second indication or the third indication is received via at least one of a MIB via a PBCH, a PDSCH associated with a SIB1, a DCI message via a PDCCH associated with the SIB1, a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.

Aspect 11 is the apparatus of aspect 9, where the at least one of the second indication or the third indication is received via at least one of RRC signaling or a MAC-CE. Aspect 12 is the apparatus of aspect 11, where the operation of the at least one RIS is associated with at least one resource pool.

Aspect 13 is the apparatus of any of aspects 9 to 12, the at least one processor being further configured to: transmit, to a third UE, at least one of a fifth indication of the one or more communication directions associated with the operation of the at least one RIS or a sixth indication of the at least one time division pattern associated with the operation of the at least one RIS based on the at least one of the second indication or the third indication.

Aspect 14 is the apparatus of aspect 13, where the at least one of the fifth indication or the sixth indication is transmitted via at least one of a PBCH, PC5-RRC signaling, or a MAC-CE.

Aspect 15 is the apparatus of aspect 1, where the first indication is received from the second UE.

Aspect 16 is the apparatus of aspect 15, where the first UE is outside the coverage area of the base station.

Aspect 17 is the apparatus of any of aspects 15 and 16, where the first indication is received via a PBCH.

Aspect 18 is the apparatus of any of aspects 15 to 17, where the at least one RIS is present in the coverage area, and the at least one processor is further configured to: receive, from the second UE, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS.

Aspect 19 is the apparatus of aspect 18, where the at least one of the second indication or the third indication is received via at least one of a PBCH, PC5-RRC signaling, or a MAC-CE.

Aspect 20 is the apparatus of any of aspects 1 to 19, further including a transceiver coupled to the at least one processor.

Aspect 21 is an apparatus for wireless communication at a base station including at least one processor coupled to a memory and configured to identify whether at least one RIS is present in a coverage area of the base station; and transmit, to a UE, a first indication of whether the at least one RIS is present in the coverage area.

Aspect 22 is the apparatus of aspect 21, where the first indication is transmitted via or associated with at least one of a MIB via a PBCH, a DMRS configuration associated with the PBCH, a sequence associated with a PSS, or a sequence associated with an SSS.

Aspect 23 is the apparatus of aspect21, where the first indication is transmitted via at least one of a PDSCH associated with a SIB1, a DMRS associated with the PDSCH associated with the SIB1, a DCI message via a PDCCH associated with the SIB1, or a DMRS associated with the PDCCH associated with the SIB1.

Aspect 24 is the apparatus of aspect21, where the first indication is transmitted via at least one of a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.

Aspect 25 is the apparatus of aspect21, where the first indication is transmitted via at least one of RRC signaling or a MAC-CE.

Aspect 26 is the apparatus of any of aspects 21 to 25, where the at least one RIS is present in the coverage area, and the at least one processor is further configured to: transmit, to the UE, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS.

Aspect 27 is the apparatus of aspect 26, where the at least one of the second indication or the third indication is transmitted via at least one of a MIB via a PBCH, a PDSCH associated with a SIB1, a DCI message via a PDCCH associated with the SIB1, a Message 2 in a 4-step RACH procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.

Aspect 28 is the apparatus of aspect 26, where the at least one of the second indication or the third indication is transmitted via at least one of RRC signaling or a MAC-CE.

Aspect 29 is the apparatus of aspect 28, where the operation of the at least one RIS is associated with at least one resource pool.

Aspect 30 is the apparatus of any of aspects 21 to 29, further including a transceiver coupled to the at least one processor.

Aspect 31 is a method of wireless communication for implementing any of aspects 1 to 30.

Aspect 32 is an apparatus for wireless communication including means for implementing any of aspects 1 to 30.

Aspect 33 is a computer-readable medium storing computer executable code, where the code when executed by a processor causes the processor to implement any of aspects 1 to 30.

Claims

An apparatus for wireless communication at a first user equipment (UE) , comprising:

a memory; and

at least one processor coupled to the memory and configured to:

receive, from a base station or a second UE, a first indication of whether at least one reconfigurable intelligent surface (RIS) is present in a coverage area of the base station; and

communicate with the base station or another UE based on the first indication.
The apparatus of claim 1, further comprising a transceiver coupled to the at least one processor, wherein the first indication is received from the base station.
The apparatus of claim 2, wherein the first indication is received via or associated with at least one of a master information block (MIB) via a physical broadcast channel (PBCH) , a demodulation reference signal (DMRS) configuration associated with the PBCH, a sequence associated with a primary synchronization signal (PSS) , or a sequence associated with a secondary synchronization signal (SSS) .
The apparatus of claim 2, wherein the first indication is received via at least one of a physical downlink shared channel (PDSCH) associated with a system information block 1 (SIB1) , a demodulation reference signal (DMRS) associated with the PDSCH associated with the SIB1, a downlink control information (DCI) message via a physical downlink control channel (PDCCH) associated with the SIB1, or a DMRS associated with the PDCCH associated with the SIB1.
The apparatus of claim 2, wherein the first indication is received via at least one of a Message 2 in a 4-step random access channel (RACH) procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.
The apparatus of claim 2, wherein the first indication is received via at least one of radio resource control (RRC) signaling or a medium access control (MAC) -control element (CE) (MAC-CE) .
The apparatus of claim 2, the at least one processor being further configured to:

transmit, to a third UE, a fourth indication of whether the at least one RIS is present in the coverage area based on the first indication.
The apparatus of claim 7, wherein the fourth indication is transmitted via a physical broadcast channel (PBCH) .
The apparatus of claim 2, wherein the at least one RIS is present in the coverage area, and the at least one processor is further configured to:

receive, from the base station, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS.
The apparatus of claim 9, wherein the at least one of the second indication or the third indication is received via at least one of a master information block (MIB) via a physical broadcast channel (PBCH) , a physical downlink shared channel (PDSCH) associated with a system information block 1 (SIB1) , a downlink control information (DCI) message via a physical downlink control channel (PDCCH) associated with the SIB1, a Message 2 in a 4-step random access channel (RACH) procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.
The apparatus of claim 9, wherein the at least one of the second indication or the third indication is received via at least one of radio resource control (RRC) signaling or a medium access control (MAC) -control element (CE) (MAC-CE) .
The apparatus of claim 11, wherein the operation of the at least one RIS is associated with at least one resource pool.
The apparatus of claim 9, the at least one processor being further configured to:

transmit, to a third UE, at least one of a fifth indication of the one or more communication directions associated with the operation of the at least one RIS or a sixth indication of the at least one time division pattern associated with the operation of the at least one RIS based on the at least one of the second indication or the third indication.
The apparatus of claim 13, wherein the at least one of the fifth indication or the sixth indication is transmitted via at least one of a physical broadcast channel (PBCH) , PC5-radio resource control (RRC) signaling, or a medium access control (MAC) -control element (CE) (MAC-CE) .
The apparatus of claim 1, wherein the first indication is received from the second UE.
The apparatus of claim 15, wherein the first UE is outside the coverage area of the base station.
The apparatus of claim 15, wherein the first indication is received via a physical broadcast channel (PBCH) .
The apparatus of claim 15, wherein the at least one RIS is present in the coverage area, and the at least one processor is further configured to:

receive, from the second UE, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS.
The apparatus of claim 18, wherein the at least one of the second indication or the third indication is received via at least one of a physical broadcast channel (PBCH) , PC5-radio resource control (RRC) signaling, or a medium access control (MAC) -control element (CE) (MAC-CE) .
A method of wireless communication at a first user equipment (UE) , comprising:

receiving, from a base station or a second UE, a first indication of whether at least one reconfigurable intelligent surface (RIS) is present in a coverage area of the base station; and

communicating with the base station or another UE based on the first indication.
An apparatus for wireless communication at a base station, comprising:

a memory; and

at least one processor coupled to the memory and configured to:

identify whether at least one reconfigurable intelligent surface (RIS) is present in a coverage area of the base station; and

transmit, to a user equipment (UE) , a first indication of whether the atleast one RIS is present in the coverage area.
The apparatus of claim 21, further comprising a transceiver coupled to the at least one processor, wherein the first indication is transmitted via or associated with at least one of a master information block (MIB) via a physical broadcast channel (PBCH) , a demodulation reference signal (DMRS) configuration associated with the PBCH, a sequence associated with a primary synchronization signal (PSS) , or a sequence associated with a secondary synchronization signal (SSS) .
The apparatus of claim 21, wherein the first indication is transmitted via at least one of a physical downlink shared channel (PDSCH) associated with a system information block 1 (SIB1) , a demodulation reference signal (DMRS) associated with the PDSCH associated with the SIB1, a downlink control information (DCI) message via a physical downlink control channel (PDCCH) associated with the SIB1, or a DMRS associated with the PDCCH associated with the SIB1.
The apparatus of claim 21, wherein the first indication is transmitted via at least one of a Message 2 in a 4-step random access channel (RACH) procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.
The apparatus of claim 21, wherein the first indication is transmitted via at least one of radio resource control (RRC) signaling or a medium access control (MAC) -control element (CE) (MAC-CE) .
The apparatus of claim 21, wherein the at least one RIS is present in the coverage area, and the at least one processor is further configured to:

transmit, to the UE, at least one of a second indication of one or more communication directions associated with operation of the at least one RIS or a third indication of at least one time division pattern associated with the operation of the at least one RIS, wherein the at least one time division pattern comprises a first time division pattern associated with a Uu link or a second time division pattern associated with a sidelink.
The apparatus of claim 26, wherein the at least one of the second indication or the third indication is transmitted via at least one of a master information block (MIB) via a physical broadcast channel (PBCH) , a physical downlink shared channel (PDSCH) associated with a system information block 1 (SIB1) , a downlink control information (DCI) message via a physical downlink control channel (PDCCH) associated with the SIB1, a Message 2 in a 4-step random access channel (RACH) procedure, a Message 4 in the 4-step RACH procedure, or a Message B in a 2-step RACH procedure.
The apparatus of claim 26, wherein the at least one of the second indication or the third indication is transmitted via at least one of radio resource control (RRC) signaling or a medium access control (MAC) -control element (CE) (MAC-CE) .
The apparatus of claim 28, wherein the operation of the at least one RIS is associated with at least one resource pool.
A method of wireless communication at abase station, comprising:

identifying whether at least one reconfigurable intelligent surface (RIS) is present in a coverage area of the base station; and

transmitting, to a user equipment (UE) , a first indication of whether the at least one RIS is present in the coverage area.