WO2022052023A1

WO2022052023A1 - Non-periodic drx paging method for sidelink device-to-device communications

Info

Publication number: WO2022052023A1
Application number: PCT/CN2020/114678
Authority: WO
Inventors: Nan Zhang
Original assignee: Qualcomm Incorporated
Priority date: 2020-09-11
Filing date: 2020-09-11
Publication date: 2022-03-17

Abstract

Aspects of the present disclosure may enable a first wireless device to configure flexible paging monitoring periods for one or more wireless devices, such that the first wireless device and the one or more wireless devices may monitor for paging from each other in a more flexible and efficient manner. In one aspect, a wireless device indicates one or more sidelink paging times to a second wireless device for paging between the first wireless device and the second wireless device. The wireless device performs discontinuous reception. The wireless device monitors for sidelink paging from the second wireless device based on the one or more sidelink paging times indicated to the second wireless device.

Description

NON-PERIODIC DRX PAGING METHOD FOR SIDELINK DEVICE-TO-DEVICE COMMUNICATIONS

INTRODUCTION

The present disclosure relates generally to communication systems, and more particularly, to sidelink communication involving paging.

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. Some aspects of wireless communication may comprise direct communication between devices based on sidelink, such as in vehicle-to-everything (V2X) and/or other device-to-device (D2D) communication. There exists a need for further improvements in sidelink technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.

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 of wireless communication is provided. The method may provide a more flexible paging system/mechanism for communication between wireless devices, such as for sidelink D2D UE to UE communications. Aspects presented herein may enable a first UE (e.g., a primary device) to configure flexible paging monitoring periods for one or more UEs (e.g., peer UEs, secondary devices) , thereby enabling the first UE and the one or more UEs to monitor for paging from each other in a more flexible and efficient manner.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided for wireless communication at a first wireless device. The apparatus indicates one or more sidelink paging times to a second wireless device for paging between the first wireless device and the second wireless device. The apparatus performs discontinuous reception. The apparatus monitors for sidelink paging from the second wireless device based on the one or more sidelink paging times indicated to the second wireless device.

In an aspect of the disclosure, a method, a computer-readable medium, and an apparatus are provided for wireless communication at a first wireless device. The apparatus receives an indication of one or more sidelink paging times from a second wireless device. The apparatus monitors for a sidelink paging from the second wireless device based on the one or more sidelink paging times.

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 including devices that communicate based on sidelink.

FIG. 2 illustrates aspects of an example sidelink slot structure.

FIG. 3 is a diagram illustrating an example of a first device and a second device configured to wireless communication including sidelink communication.

FIG. 4 illustrates an example sidelink communication system.

FIG. 5 illustrates an example of discontinuous reception (DRX) including an extension of a DRX ON duration.

FIG. 6 illustrates example communication flow between two UEs.

FIG. 7 is a diagram illustrating an example of paging time configuration according to aspects of the present disclosure.

FIG. 8 is a diagram illustrating an example of paging time configuration according to aspects of the present disclosure.

FIG. 9 is a diagram illustrating an example of paging time configuration according to aspects of the present disclosure.

FIG. 10 is a diagram illustrating an example of paging time configuration according to aspects of the present disclosure.

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

FIG. 12 is a diagram illustrating an example of a hardware implementation for an example apparatus.

FIG. 13 is a flowchart of a method of wireless communication.

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 described 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 described 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 described 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 examples, 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 aforementioned 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 accessed by a computer.

A UE may reduce power consumption through discontinuous reception (DRX) in which the UE monitors for communication or transmits communication during a DRX ON duration and does not monitor for communication or transmit communication during a DRX OFF duration. The DRX OFF duration may correspond to a time during which the UE operates in a lower power mode, a sleep mode, etc. By having periods during which the UE does not monitor for or transmit communication, the UE may save power or extend battery life for the UE. However, sidelink communication that is exchanged direction between devices may rely on discovery messages for sidelink UEs to find nearby UEs or may rely on sensing of resource reservations by other UEs in order to select resources for transmission. A UE in a DRX OFF duration will miss discovery messages from other UEs and will not sense resource reservations. If multiple UEs operate using different DRX patterns, discovery between UEs may become more difficult.

The UE may provide the information about the DRX pattern in a broadcast announcement message and/or in a reply to a sidelink discovery message. The UE may monitor for sidelink communication based on the DRX pattern. A second UE may use the DRX pattern to transmit communication to the first UE within the first UE’s DRX ON duration. In some examples, both UEs may operate based on DRX, and the two UEs may transmit sidelink communication to each other at times that fall within the DRX ON duration for both UEs.

In some examples, the UE may perform sidelink activity, such as transmitting, receiving, sensing, or reservation of resources, within a DRX ON duration of the DRX pattern, e.g., without extending the DRX ON duration. For example, the UE may postpone a retransmission that would occur outside of a DRX ON duration until the next DRX ON duration. The UE may reserve resources within a current DRX ON duration and/or in a later DRX ON duration.

Aspects presented herein enable a UE to configure flexible paging monitoring periods for one or more UEs (e.g., peer UEs) , such that the first UE and the one or more UEs may monitor for paging from each other in a more flexible and efficient manner.

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.

A link between a UE 104 and a base station 102 or 180 may be established as an access link, e.g., using a Uu interface. Other communication may be exchanged between wireless devices based on sidelink. For example, some UEs 104 may communicate with each other directly using a device-to-device (D2D) communication link 158. In some examples, 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.

Some examples of sidelink communication may include vehicle-based communication devices that can communicate from vehicle-to-vehicle (V2V) , vehicle-to-infrastructure (V2I) (e.g., from the vehicle-based communication device to road infrastructure nodes such as a Road Side Unit (RSU) ) , vehicle-to-network (V2N) (e.g., from the vehicle-based communication device to one or more network nodes, such as a base station) , vehicle-to-pedestrian (V2P) , cellular vehicle-to-everything (C-V2X) , and/or a combination thereof and/or with other devices, which can be collectively referred to as vehicle-to-anything (V2X) communications. Sidelink communication may be based on V2X or other D2D communication, such as Proximity Services (ProSe) , etc. In addition to UEs, sidelink communication may also be transmitted and received by other transmitting and receiving devices, such as Road Side Unit (RSU) 107, etc. Sidelink communication may be exchanged using a PC5 interface, such as described in connection with the example in FIG. 2. Although the following description, including the example slot structure of FIG 2, may provide examples for sidelink communication in connection with 5G NR, the concepts described herein may be applicable to other similar areas, such as LTE, LTE-A, CDMA, GSM, and other wireless technologies.

A UE 104 may include a sidelink paging component 198 configured to indicate one or more sidelink paging times to a second wireless device for paging between the first wireless device and the second wireless device. The sidelink paging component 198 may be configured to perform discontinuous reception. The sidelink paging component 198 may be configured to monitor for sidelink paging from the second wireless device based on the one or more sidelink paging times indicated to the second wireless device. The sidelink paging component 198 may be configured to enable a first wireless device (e.g., a primary device) to configure flexible paging monitoring periods for one or more wireless devices (e.g., peer wireless devices, secondary devices) , thereby enabling the first wireless device and the one or more wireless devices to monitor for paging from each other in a more flexible and efficient manner.

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 each other 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 between the 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 referred to 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 may use spectrum up to Y MHz (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 respect to 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) .

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 used by the Wi-Fi AP 150. The small cell 102', employing NR in an unlicensed 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) . The frequencies between FR1 and FR2 are often referred to as mid-band frequencies. 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 referred to (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.

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, 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 referred to 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. Similarly, beamforming may be applied for sidelink communication, e.g., between UEs.

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. Although this example is described for the base station 180 and UE 104, the aspects may be similarly applied between a first and second device (e.g., a first and second UE) for sidelink communication.

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 Packet Data 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, other AMFs 193, a Session Management Function (SMF) 194, and a User 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 referred to 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) , a transmit 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, a multimedia 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 referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc. ) . The UE 104 may also be referred to 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.

FIG. 2 illustrates example diagrams 200 and 210 illustrating example aspects of slot structures that may be used for sidelink communication (e.g., between UEs 104, RSU 107, etc. ) . The slot structure may be within a 5G/NR frame structure. 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. This is merely one example, and other wireless communication technologies may have different frame structures and/or different channels for sidelink communication. A frame (10 ms) may be divided into 10 equally sized subframes (1 ms) . Each subframe 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 7 or 14 symbols, depending on the slot configuration. For slot configuration 0, each slot may include 14 symbols, and for slot configuration 1, each slot may include 7 symbols. Diagram 200 illustrates a single resource block of a single slot transmission, e.g., which may correspond to a 0.5 ms transmission time interval (TTI) . A physical sidelink control channel may be configured to occupy multiple physical resource blocks (PRBs) , e.g., 10, 12, 15, 20, or 25 PRBs. The PSCCH may be limited to a single sub-channel. A PSCCH duration may be configured to be 2 symbols or 3 symbols, for example. A sub-channel may comprise 10, 15, 20, 25, 50, 75, or 100 PRBs, for example. The resources for a sidelink transmission may be selected from a resource pool including one or more subchannels. As a non-limiting example, the resource pool may include between 1-27 subchannels. A PSCCH size may be established for a resource pool, e.g., as between 10-100 %of one subchannel for a duration of 2 symbols or 3 symbols. The diagram 210 in FIG. 2 illustrates an example in which the PSCCH occupies about 50%of a subchannel, as one example to illustrate the concept of PSCCH occupying a portion of a subchannel. The physical sidelink shared channel (PSSCH) occupies at least one subchannel. The PSCCH may include a first portion of sidelink control information (SCI) , and the PSSCH may include a second portion of SCI in some examples.

A resource grid may be used to represent the frame structure. Each time slot may include 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. 2, some of the REs may comprise control information in PSCCH and some REs may comprise demodulation RS (DMRS) . At least one symbol may be used for feedback. FIG. 2 illustrates examples with two symbols for a physical sidelink feedback channel (PSFCH) with adjacent gap symbols. A symbol prior to and/or after the feedback may be used for turnaround between reception of data and transmission of the feedback. The gap enables a device to switch from operating as a transmitting device to prepare to operate as a receiving device, e.g., in the following slot. Data may be transmitted in the remaining REs, as illustrated. The data may comprise the data message described herein. The position of any of the data, DMRS, SCI, feedback, gap symbols, and/or LBT symbols may be different than the example illustrated in FIG. 2. Multiple slots may be aggregated together in some examples.

FIG. 3 is a block diagram 300 of a first wireless communication device 310 in communication with a second wireless communication device 350 based on sidelink. In some examples, the

devices

310 and 350 may communicate based on V2X or other D2D communication. The communication may be based on sidelink using a PC5 interface. The devices 310 and the 350 may comprise a UE, an RSU, a base station, etc. Packets may be provided to a controller/processor 375 that implements layer 3 and layer 2 functionality. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer.

The transmit (TX) processor 316 and the 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-PSK) , 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 may be derived from a reference signal and/or channel condition feedback transmitted by the device 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 an RF carrier with a respective spatial stream for transmission.

At the device 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 device 350. If multiple spatial streams are destined for the device 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 device 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 device 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. The controller/processor 359 may provide demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing. 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 described in connection with the transmission by device 310, the controller/processor 359 may provide 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 device 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 354 TX. Each transmitter 354 TX may modulate an RF carrier with a respective spatial stream for transmission.

The transmission is processed at the device 310 in a manner similar to that described in connection with the receiver function at the device 350. Each receiver 318 RX receives a signal through its respective antenna 320. Each receiver 318 RX 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. The controller/processor 375 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing. 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, the controller/processor 359, the TX processor 316, the RX processor 370, or the controller/processor 375 may be configured to perform aspects in connection with the sidelink paging component 198 of FIG. 1.

FIG. 4 illustrates an example 400 of wireless communication between devices based on sidelink communication. The communication may be based on a slot structure comprising aspects described in connection with FIG. 2. For example, transmitting UE 402 may transmit a transmission 414, e.g., comprising a control channel and/or a corresponding data channel, that may be received by receiving

UEs

404, 406, 408. A control channel may include information for decoding a data channel and may also be used by receiving device to avoid interference by refraining from transmitting on the occupied resources during a data transmission. The number of TTIs, as well as the RBs that will be occupied by the data transmission, may be indicated in a control message from the transmitting device. The

UEs

402, 404, 406, 408 may each be capable of operating as a transmitting device in addition to operating as a receiving device. Thus,

UEs

406, 408 are illustrated as transmitting

transmissions

416, 420. The

transmissions

414, 416, 420 may be broadcast or multicast to nearby devices. For example, UE 414 may transmit communication intended for receipt by other UEs within a range 401 of UE 414. Additionally, or alternatively, the RSU 407 may receive communication from and/or transmit communication 418 to

UEs

402, 404, 406, 408.

For some UEs, such as vehicle UE (VUE) , the UE may have access to larger amounts of battery power, and power savings may not be as important as other factors. For example, a VUE may continually sense sidelink resources, such as a pool of resources, to identify resources reserved by other UEs whether for reception of the sidelink communication from the other UEs or for selection from the available resources for sidelink transmission. For other UEs, power savings and longer battery lives may be more significant.

As presented herein a

UE

402, 404, 406, or 408 may reduce power consumption through DRX in which the

UE

402, 404, 406, or 408 monitors for communication or transmits communication during a DRX ON duration and does not monitor for communication or transmit communication during a DRX OFF duration. For example, the UE may monitor for sidelink control information (SCI) discontinuously using a sleep and wake cycle. The DRX OFF duration may correspond to a time during which the UE operates in a lower power mode, a sleep mode, etc. During the DRX OFF duration, the UE may shut down, turn off, or not use a radio frequency (RF) function. The DRX pattern may include one or more timers or values, such as an ON duration timer or a value that indicates the starting point of the DRX ON duration and/or the DRX OFF duration, etc. The ON duration timer may indicate a period of time, e.g., in consecutive symbols, slots, subframes, or TTIs, in which the UE wakes up from the OFF duration and monitors for control signaling. A DRX cycle may include a periodic repetition of the DRX ON duration and the DRX OFF duration.

By having periods during which the UE does not monitor for or transmit communication, the UE may save power or extend battery life for the UE. For example, DRX for sidelink may provide power savings, e.g., at a physical layer or a medium access control (MAC) layer. Power savings may be helpful in sidelink applications such as public safety applications, commercial applications, wearables, etc.

DRX may also be used by a UE for communication over a link 120, e.g., a cellular link, access link or Uu link, between a UE 104 and a base station 102 or 180, as illustrated in FIG. 1. The base station 102 or 180 may configure the UE 104 with a DRX configuration. The base station may configure DRX parameters for the UE that indicate the DRX cycle, the DRX ON duration, etc. Additionally, the base station 102 or 180 may schedule the communication with the UE 104 based on the UE’s DRX configuration because the base station is aware of the DRX configuration that the base station 102 or 180 provided to the UE 104. FIG. 5 illustrates an example of DRX cycle 500 that may be configured by a base station 102 or 180 for a UE 104 using an access link 120 with the base station. The UE 104 may monitor for PDCCH from the base station 102 or 180 during the DRX ON duration and may skip monitoring for the PDCCH during the DRX OFF duration. If the UE receives a PDCCH during the on duration, such as illustrated at 502, the UE may stay awake for an extended period of time based on an inactivity timer that starts upon reception of the PDCCH. If the UE 104 does not receive downlink communication from the base station 102 or 180 during the duration of the inactivity timer, the UE may stop monitoring, e.g., enter a sleep mode or lower power mode, for the remaining DRX OFF duration.

While the DRX mechanism may provide various benefits for communications between a base station and a UE (e.g., phones, narrowband-internet of things (NB-IoT) , etc. ) , the mechanism may not be flexible for device-to-device (D2D) communications and/or for communications not involving a base station. For example, for sidelink D2D communications, the DRX mechanism may lead to some power waste for UEs that are not communicating in regular intervals, where the UEs may be communicating with each other upon certain triggering events (e.g., manufacturing involving automation components, smart phone censors, etc. ) . By configuring a periodic DRX cycles for UEs that are not expecting pagings in a period of time, additional power may be wasted by the UE for monitoring the pagings. On the other hand, if the DRX cycle is enlarged for these UEs, it may lead to worse data service latency as the UEs may not be able to communicate with each other during the enlarged inactive (e.g., sleep mode) period.

Aspects presented herein may provide a more flexible paging system/mechanism for communications between wireless devices, such as for sidelink D2D UE to UE communications. Aspects presented herein may enable a first UE (e.g., a primary device) to configure flexible paging monitoring periods for one or more UEs (e.g., peer UEs, secondary devices) , thereby enabling the first UE and the one or more UEs to monitor for pagings from each other in a more flexible and efficient manner.

FIG. 6 is a diagram 600 illustrating an example communication flow between two UEs according to aspects of the present disclosure. In one aspect, a first UE (e.g., UE-A) may assign a single or a few next non-periodic paging occasion occurring time to a second UE (e.g., UE-B) . For example, at 606, a UE-A 602 may indicate (e.g., via a message or signaling) one or more sidelink paging times to a UE-B 604. The UE-A 602 may be a primary device whereas the UE-B 604 may be a secondary device, and there may also be multiple UE-Bs. The one or more sidelink paging times may include a duration (e.g., 610) in which the UE-A and UE-B do not monitor for paging (s) (e.g., sidelink paging) from each other and/or transmit paging (s) to each other, and/or a duration (e.g., 612) in which the UE-A and UE-B may monitor for paging (s) from each other and/or transmit paging (s) to each other.

For example, after the UE-A 602 indicates the one or more sidelink paging times to the UE-B 604, the UE-A 602 may perform the discontinuous reception 608, where the UE-A 602 may not monitor for paging (s) (e.g., sidelink paging) from the UE-B 604 and/or may not transmit sidelink paging (s) to the UE-B 604 during a non-monitoring paging period 610. During the non-monitoring paging period 610, the UE-A 602 may enter into an idle mode or a sleep mode (e.g., to conserve power) . After the non-monitoring paging period 610, the UE-A 602 may transition into a wake up mode, and the UE-A 602 may monitor for paging (s) from the UE-B 604 and/or transmit paging (s) (e.g., at 614) to the UE-B 604 in a monitoring and paging period 612. Similarly, after the UE-B 604 receives the one or more sidelink paging times from the UE-A 602, the UE-B 604 may perform the discontinuous reception 608, where the UE-B 604 may not monitor for paging (s) (e.g., sidelink paging) from the UE-A 602 and/or may not transmit sidelink paging (s) to the UE-A 602 during the non-monitoring paging period 610. During the non-monitoring paging period 610, the UE-B 604 may enter into an idle mode or a sleep mode. After the non-monitoring paging period 610, the UE-B 604 may transition into a wake up mode, and the UE-B 604 may monitor for paging (s) from the UE-A 602 and/or transmit paging (s) (e.g., at 614) to the UE-A 602 in the monitoring and paging period 612. After the UE-B 604 is able to monitor for pagings, such as during the monitoring and paging period 612, the UE-A 602 may transmit a paging to the UE-B 604, and may configure or indicate one or more sidelink paging times to the UE-B 604, such as shown at 616.

In one aspect, the paging time (e.g., at 606 of FIG. 6) indicated by the first UE (e.g., UE-A) may be a single value. For example, as shown by diagram 700 of FIG. 7, a UE-A 702 may indicate a paging time 706 (e.g., 30 seconds) to a UE-B 704. Then, both UEs may not monitoring for paging (s) from each other and transmitting paging (s) to each other during the non-monitoring and paging period 708 (e.g., 30 seconds) as indicated by the paging time 706, where they may enter into an idle or a sleep mode. After the non-monitoring and paging period 708, the UE-A 702 and the UE-B 704 may monitor for paging (s) from each other and/or transmit paging (s) to each other during the monitoring and paging period 710. The duration for the monitoring and paging period 710 may also be indicated by the UE-A 702 (e.g., such as included in the paging time) , or it may be pre-configured and defined at the UE-A 702 and/or the UE-B 704 (e.g., a fixed or standard value) . During or after the monitoring and paging period 710, the UE-A 702 may indicate another paging time 712 (e.g., 50 seconds) to the UE-B 704. Similarly, both UEs may not monitoring for paging (s) from each other and transmitting paging (s) to each other during the non-monitoring and paging period 714 (e.g., 50 seconds) based on the paging time 712, where they may enter into the idle or the sleep mode. After the non-monitoring and paging period 714, the UE-A 702 and the UE-B 704 may monitor for paging (s) from each other and/or transmit paging (s) to each other during the monitoring and paging period 716 and the process may continue and repeat. In one configuration, if the UE-B 704 does not receive the paging time 712 (e.g., another configuration or indication for paging time) , the UE-B 704 and optionally the UE-A 702 may apply a default paging monitoring/transmitting cycle, where the UE-B 704 may monitor for paging (s) from UE-A 702 at a default interval (e.g., 20 seconds) . In another configuration, if the UE-B 704 does not receive the paging time 712, the UE-B 704 may continue to follow the duration or paging time indicated by the paging time 706 (i.e., the previous or latest paging time received) , where the UE-B 704 may monitor for paging (s) from UE-A 702 at the interval defined by the paging time 706 (e.g., 30 seconds) .

In another aspect, the one or more paging times (e.g., at 606 of FIG. 6) indicated by the first UE (e.g., UE-A) may include multiple page monitoring and transmitting periods (e.g., non-periodic paging occasions) . For example, as shown by diagram 800 of FIG. 8, a UE-A 802 may transmit or indicate multiple paging times 806 to a UE-B 804, where the multiple paging times 806 may include a first duration 808 (e.g., 120 seconds) , a second duration 812 (e.g., 200 seconds) and a third duration 816 (e.g., 210 seconds) . Based on the multiple paging times 806, both UEs may monitor for paging (s) from each other and/or transmitting paging (s) to each other at the expiry of each duration, such as at the monitoring and

paging periods

810, 814 and 818. For example, the UE-A 802 and the UE-B 804 may enter into an idle or a sleep mode, and wake up 120 seconds later to check for the paging information, if any. Then, the UE-A 802 and the UE-B 804 may enter into the idle or the sleep mode again, and wake up 200 seconds later (e.g., from the time the multiple paging times 806 is transmitted or received) to check for the paging information, if any. Then, the UE-A 802 and the UE-B 804 may enter into the idle or the sleep mode, again, and wake up 210 seconds later (e.g., from the time the multiple paging times 806 is transmitted or received) to check for the paging information, if any. In another example, as shown by diagram 900 of FIG. 9, a UE-A 902 may transmit or indicate multiple paging times 906 to a UE-B 904, where the multiple paging times 906 may include a first duration 908 (e.g., 60 seconds) , a second duration 912 (e.g., 80 seconds) and a third duration 916 (e.g., 50 seconds) , and optionally the monitoring and

paging periods

910, 914 and 918 (e.g., may also be pre-configured) . Based on the multiple paging times 906, both UEs may monitor for paging (s) from each other and/or transmitting paging (s) to each other at the expiry of each duration, such as at the monitoring and

paging periods

910, 914 and 918. For example, the UE-A 902 and the UE-B 904 may enter into an idle or a sleep mode, and wake up 60 seconds later to check for the paging information, if any (e.g., during the monitoring and paging period 910) . Then, the UE-A 902 and the UE-B 904 may enter into the idle or the sleep mode again, and wake up 80 seconds later (e.g., after the start/end of the monitoring and paging period 910 depending on the configuration) to check for the paging information, if any (e.g., during the monitoring and paging period 914) . Then, the UE-A 902 and the UE-B 904 may enter into the idle or the sleep mode again, and wake up 50 seconds later (e.g., after the start/end of the monitoring and paging period 914 depending on the configuration) to check for the paging information, if any (e.g., during the monitoring and paging period 918) . The three paging times are merely examples to illustrate the concept, and the aspects presented herein may be applied to any number of paging times and any duration of paging times.

Similarly, in some examples, if the UE-

B

804 or 904 does not receive the multiple paging times 806 or 906 (e.g., another configuration or indication for paging time) , the UE-

B

804 or 904 and optionally the UE-

A

802 or 902 may apply a default paging monitoring/transmitting cycle, where the UE-

B

804 or 904 may monitor for paging (s) from UE-

A

802 or 902 at a default interval. In another example, if the UE-

B

804 or 904 does not receive the paging time 712, the UE-

B

804 or 904 may continue to follow the duration or paging time indicated by the paging time 806 or 906 (i.e., the previous or latest paging time received) , where the UE-

B

804 or 904 may monitor for paging (s) from UE-

A

802 or 902 at intervals defined by the

paging time

806 or 906 or one of the intervals (e.g., the last interval) defined by the

paging time

806 or 906.

In another aspect, the UE-A (e.g., 602, 702, 802, 902) may have the authority to modify or update the paging ordered timelines to the UE-B (e.g., 604, 704, 804, 904) at any time when UE-A and UE-B are wake-up, such as during the monitoring and paging periods (e.g., 612, 710, 810, 910) . If the UE-A has not assigned any paging time to the UE-B, the UE-A and UE-B may use a default paging cycle time. In addition, the UE-A may also indicate a paging time (e.g., 30 seconds) and a number of repetitions (e.g., five) for the paging time to the UE-B, such that the UE-A and the UE-B may monitor for the paging period based on the paging time and the number of repetition (e.g., the UE-A and the UE-B may monitor for paging every 30 seconds for five times) . In some examples, the paging time indicated/assigned by the UE-A may take higher priority to overwrite a default paging cycle time on the UE-B and/or the UE-A. For example, as shown by diagram 1000 of FIG. 10, a UE-A 1002 and/or a UE-B 1004 may be following a default cycle that includes a non-monitoring and paging period 1008 and a monitoring and paging period 1010. During the default cycle, the UE-A 1002 may indicate a paging time 1006 to the UE-B 1004, where the paging time 1006 may indicate a different non-monitoring and paging period 1012 and optionally a monitoring and paging period 1014 (e.g., the monitoring and paging period 1014 may be the same as the monitoring and paging period 1010 such as based on a default or preconfigured value) . Based on the paging time 1006, the UE-A 1002 and the UE-B 1004 may overwrite the default paging cycle time, and follow the non-monitoring and paging period 1012 and optionally the monitoring and paging period 1014 as indicated by the paging time 1006. Similarly, if the UE-A 1002 does not transmit another paging time to the UE-B 1004 afterwards, the UE-A 1002 and the UE-B 1004 may return to the default cycle (e.g., 1008 and 1010) or continue to repeat the time indicated by the paging time 1006 (e.g., 1012, 1014) depending on the configuration.

FIG. 11 is a flowchart 1100 of a method of wireless communication. The method may be performed by a first wireless device communicating based on sidelink (e.g., the

UE

104, 402, 404, 406, 408, 602, 702, 802, 902, 1002, the

device

310 or 350, the RSU 407; the apparatus 1202) . Optional aspects are illustrated with a dashed line. The method may enable the first wireless device (e.g., a primary device) to configure flexible paging monitoring periods for one or more wireless devices (e.g., peer UEs, secondary devices) , thereby enabling the first wireless device and the one or more wireless devices to monitor for paging from each other in a more flexible and efficient manner.

At 1102, the first wireless device may indicate one or more sidelink paging times to a second wireless device for paging between the first wireless device and the second wireless device, such as descried in connection with FIGs. 6-10. For example, at 606, the UE-A 602 may transmit one or more sidelink paging times to the UE-B 604. Each of the one or more sidelink paging times may include a duration and the first wireless device may not monitor for the sidelink paging from the second wireless device during the duration between paging occasions (e.g., the non-monitoring and

paging period

610, 708, 908, etc. ) . In one configuration, the first wireless device may indicate multiple sidelink paging times and monitors for the sidelink paging from the second wireless device based on each of the multiple sidelink paging times, such as described in connection with FIGs. 8 and 9. In such configuration, the one or more sidelink paging times may be non-periodic (e.g., each paging time is different) . In another configuration, the first wireless device may indicate a single paging time, such as described in connection with FIG. 7. The one or more sidelink paging times may include a duration (e.g., the non-monitoring and

paging period

610, 708, 908, etc. ) , where the first wireless device may repeat monitoring for sidelink paging based on the duration for a defined number of times. In one configuration, the one or more sidelink paging time may be applied in place of a default sidelink paging cycle of the second wireless device.

At 1104, the first wireless device may perform discontinuous reception, such as descried in connection with FIGs. 6-10. For example, after the UE-A 602 indicates the one or more sidelink paging times to the UE-B 604, the UE-A 602 may perform the discontinuous reception 608, where the UE-A 602 may not monitor for paging (s) (e.g., sidelink paging) from the UE-B 604 and/or may not transmit sidelink paging (s) to the UE-B 604 during a non-monitoring paging period 610. During the discontinuous reception, the first wireless device may enter into an idle mode or a sleep mode after indicating the one or more sidelink paging times to the second wireless device. Then, the first wireless device may wake up based on the one or more sidelink paging times to monitor for the sidelink paging from the second wireless device.

At 1106, the first wireless device may monitor for sidelink paging from the second wireless device based on the one or more sidelink paging times indicated to the second wireless device, such as descried in connection with FIGs. 6-10. For example, after the non-monitoring paging period 610, the UE-A 602 may transition into a wake up mode, and the UE-A 602 may monitor for paging (s) from the UE-B 604 and/or transmit paging (s) to the UE-B 604 in a monitoring and paging period 612. Also, based on the one or more sidelink paging times, the first wireless device may transmit a sidelink page to the second wireless device in a paging occasion.

At 1108, the first wireless device may indicate a different paging time to the second wireless device after the one or more sidelink paging times expire, such as descried in connection with FIG. 7. For example, the UE-A 702 may indicate another paging time 712 to the UE-B 704 after the paging time 706 expires. If the first wireless device does not indicate a different paging time to the second wireless device, the first wireless device may apply a default paging cycle.

FIG. 12 is a diagram 1200 illustrating an example of a hardware implementation for an apparatus 1202. The apparatus 1202 is a UE and includes a cellular baseband processor 1204 (also referred to as a modem) coupled to a cellular RF transceiver 1222 and one or more subscriber identity modules (SIM) cards 1220, an application processor 1206 coupled to a secure digital (SD) card 1208 and a screen 1210, a Bluetooth module 1212, a wireless local area network (WLAN) module 1214, a Global Positioning System (GPS) module 1216, and a power supply 1218. The cellular baseband processor 1204 communicates through the cellular RF transceiver 1222 with the UE 104 and/or BS 102/180. The cellular baseband processor 1204 may include a computer-readable medium /memory. The computer-readable medium /memory may be non-transitory. The cellular baseband processor 1204 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 1204, causes the cellular baseband processor 1204 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 1204 when executing software. The cellular baseband processor 1204 further includes a reception component 1230, a communication manager 1232, and a transmission component 1234. The communication manager 1232 includes the one or more illustrated components. The components within the communication manager 1232 may be stored in the computer-readable medium /memory and/or configured as hardware within the cellular baseband processor 1204. The cellular baseband processor 1204 may be a component of the device 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 1202 may be a modem chip and include just the baseband processor 1204, and in another configuration, the apparatus 1202 may be the entire UE (e.g., see 350 of FIG. 3) and include the additional modules of the apparatus 1202.

The communication manager 1232 includes a paging time component 1240 that is configured to indicate one or more sidelink paging times to a second wireless device for paging between the first wireless device and the second wireless device, e.g., as described in connection with 1102 of FIG. 11. The communication manager 1232 includes a DRX component 1242 that is configured to perform discontinuous reception, e.g., as described in connection with 1104 of FIG. 11. The communication manager 1232 includes a monitoring and paging component 1244 that is configured to monitor for sidelink paging from the second wireless device based on the one or more sidelink paging times indicated to the second wireless device, e.g., as described in connection with 1106 of FIG. 11.

The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of FIG. 11. As such, each block in the aforementioned flowcharts of FIG. 11 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.

In one configuration, the apparatus 1202, and in particular the cellular baseband processor 1204, may include means for indicating one or more sidelink paging times to a second wireless device for paging between the first wireless device and the second wireless device; means for performing discontinuous reception; and means for monitoring for sidelink paging from the second wireless device based on the one or more sidelink paging times indicated to the second wireless device. The apparatus 1202 may further include means for transmitting a sidelink page to the second wireless device in a paging occasion based on the one or more sidelink paging times. The apparatus 1202 may further include means for entering into an idle mode or a sleep mode after indicating the one or more sidelink paging times to the second wireless device; and means for waking up based on the one or more sidelink paging times to monitor for the sidelink paging from the second wireless device. The apparatus 1202 may further include means for indicating a different paging time to the second wireless device after the one or more sidelink paging times expire. The apparatus 1202 may further include means for receiving an indication of one or more sidelink paging times from a second wireless device; and means for monitoring for a sidelink paging from the second wireless device based on the one or more sidelink paging times. The aforementioned means may be one or more of the aforementioned components of the apparatus 1202 configured to perform the functions recited by the aforementioned means. As described supra, the apparatus 1202 may include the TX Processor 368, the RX Processor 356, and the controller/processor 359. As such, in one configuration, the aforementioned means may be the TX Processor 368, the RX Processor 356, and the controller/processor 359 configured to perform the functions recited by the aforementioned means.

FIG. 13 is a flowchart 1300 of a method of wireless communication. The method may be performed by a first wireless device communicating based on sidelink (e.g., the

UE

104, 402, 404, 406, 408, 604, 704, 804, 904, 1004, the

device

310 or 350, the RSU 407; the apparatus 1402) . Optional aspects are illustrated with a dashed line. The method may enable the first wireless device (e.g., a secondary device) to be configured with a flexible paging and page monitoring period (s) .

At 1302, the first wireless device may receive an indication of one or more sidelink paging times from a second wireless device, such as descried in connection with FIGs. 6-10. For example, at 606, the UE-A 602 may transmit one or more sidelink paging times to the UE-B 604. Each of the one or more sidelink paging times may include a duration and the first wireless device may not monitor for the sidelink paging from the second wireless device during the duration between paging occasions (e.g., the non-monitoring and

paging period

610, 708, 908, etc. ) . In one configuration, the first wireless device may receive multiple sidelink paging times and monitors for the sidelink paging from the second wireless device based on each of the multiple sidelink paging times, such as described in connection with FIGs. 8 and 9. In such configuration, the one or more sidelink paging times may be non-periodic (e.g., each paging time is different) . In another configuration, the first wireless device may receive a single paging time, such as described in connection with FIG. 7. The one or more sidelink paging times may include a duration (e.g., the non-monitoring and

paging period

610, 708, 908, etc. ) , where the first wireless device may repeat monitoring for sidelink paging based on the duration for a defined number of times. In one configuration, the one or more sidelink paging time may be applied in place of a default sidelink paging cycle of the first wireless device.

After receiving the indication of one or more sidelink paging times from the second wireless device, the first wireless device may perform discontinuous reception, such as descried in connection with FIGs. 6-10. For example, after the UE-B 604 receives the one or more sidelink paging times from the UE-A 602, the UE-B 604 may perform the discontinuous reception 608, where the UE-B 604 may not monitor for paging (s) (e.g., sidelink paging) from the UE-A 602 and/or may not transmit sidelink paging (s) to the UE-A 602 during a non-monitoring paging period 610. During the discontinuous reception, the first wireless device may enter into an idle mode or a sleep mode after receiving the one or more sidelink paging times from the second wireless device. Then, the first wireless device may wake up based on the one or more sidelink paging times to monitor for the sidelink paging from the second wireless device.

At 1304, the first wireless device may monitor for a sidelink paging from the second wireless device based on the one or more sidelink paging times, such as descried in connection with FIGs. 6-10. For example, after the non-monitoring paging period 610, the UE-B 604 may transition into a wake up mode, and the UE-B 604 may monitor for paging (s) from the UE-A 602 and/or transmit paging (s) to the UE-A 602 in a monitoring and paging period 612. Also, based on the one or more sidelink paging times, the first wireless device may transmit a sidelink page to the second wireless device in a paging occasion.

At the expiration of the one or more sidelink paging times, the first wireless device may receive a different paging time from the second wireless device, such as descried in connection with FIG. 7. For example, the UE-A 702 may indicate another paging time 712 to the UE-B 704 after the paging time 706 expires. If the first wireless device does not receive a different paging time from the second wireless device, the first wireless device may apply a default paging cycle.

FIG. 14 is a diagram 1400 illustrating an example of a hardware implementation for an apparatus 1402. The apparatus 1402 is a UE and includes a cellular baseband processor 1404 (also referred to as a modem) coupled to a cellular RF transceiver 1422 and one or more subscriber identity modules (SIM) cards 1420, an application processor 1406 coupled to a secure digital (SD) card 1408 and a screen 1410, a Bluetooth module 1412, a wireless local area network (WLAN) module 1414, a Global Positioning System (GPS) module 1416, and a power supply 1418. The cellular baseband processor 1404 communicates through the cellular RF transceiver 1422 with the UE 104 and/or BS 102/180. The cellular baseband processor 1404 may include a computer-readable medium /memory. The computer-readable medium /memory may be non-transitory. The cellular baseband processor 1404 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 1404, causes the cellular baseband processor 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 cellular baseband processor 1404 when executing software. The cellular baseband processor 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 cellular baseband processor 1404. The cellular baseband processor 1404 may be a component of the device 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 1402 may be a modem chip and include just the baseband processor 1404, and in another configuration, the apparatus 1402 may be the entire UE (e.g., see 350 of FIG. 3) and include the additional modules of the apparatus 1402.

The communication manager 1432 includes a paging time component 1440 that is configured to receive an indication of one or more sidelink paging times from a second wireless device, e.g., as described in connection with 1302 of FIG. 13. The communication manager 1432 includes a monitoring and paging component 1442 that is configured to monitor for a sidelink paging from the second wireless device based on the one or more sidelink paging times, e.g., as described in connection with 1304 of FIG. 13.

The apparatus may include additional components that perform each of the blocks of the algorithm in the aforementioned flowcharts of FIG. 13. As such, each block in the aforementioned flowcharts of FIG. 13 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.

In one configuration, the apparatus 1402, and in particular the cellular baseband processor 1404, may include means for receiving an indication of one or more sidelink paging times from a second wireless device; and means for monitoring for a sidelink paging from the second wireless device based on the one or more sidelink paging times. The apparatus 1402 may further include means for transmitting a sidelink page to the second wireless device in a paging occasion based on the one or more sidelink paging times. The apparatus 1402 may further include means for entering into an idle mode or a sleep mode after receiving the one or more sidelink paging times from the second wireless device; and means for waking up based on the one or more sidelink paging times to monitor for the sidelink paging from the second wireless device. The apparatus 1402 may further include means for receiving a sidelink page from the second wireless device in a paging occasion based on the one or more sidelink paging times. The apparatus 1402 may further include means for receiving a different paging time from the second wireless device after the one or more sidelink paging times expire. The apparatus 1402 may further include means for applying the one or more sidelink paging time in place of a default sidelink paging cycle of the first wireless device. The aforementioned means may be one or more of the aforementioned components of the apparatus 1402 configured to perform the functions recited by the aforementioned means. As described supra, the apparatus 1402 may include the TX Processor 368, the RX Processor 356, and the controller/processor 359. As such, in one configuration, the aforementioned means may be the TX Processor 368, the RX Processor 356, and the controller/processor 359 configured to perform the functions recited by the aforementioned means.

The following examples are illustrative only and aspects thereof may be combined with aspects of other examples or teaching described herein, without limitation.

Example 1 is a method of wireless communication at a first wireless device, comprising: indicating one or more sidelink paging times to a second wireless device for paging between the first wireless device and the second wireless device; performing discontinuous reception; and monitoring for sidelink paging from the second wireless device based on the one or more sidelink paging times indicated to the second wireless device.

In Example 2, the method of Example 1 further includes that each of the one or more sidelink paging times comprises a duration and the first wireless device does not monitor for the sidelink paging from the second wireless device during the duration between paging occasions.

In Example 3, the method of Example 1 or Example 2 further includes that the first wireless device indicates multiple sidelink paging times and monitors for the sidelink paging from the second wireless device based on each of the multiple sidelink paging times.

In Example 4, the method of any of Examples 1-3 further includes that the first wireless device indicates a single paging time.

In Example 5, the method of any of Examples 1-4 further includes that the one or more sidelink paging times are non-periodic.

In Example 6, the method of any of Examples 1-5 further includes that the one or more sidelink paging times include a duration, wherein the first wireless device repeats monitoring for sidelink paging based on the duration for a defined number of times.

In Example 7, the method of any of Examples 1-6 further comprises: transmitting a sidelink page to the second wireless device in a paging occasion based on the one or more sidelink paging times.

In Example 8, the method of any of Examples 1-7 further comprises: entering into an idle mode or a sleep mode after indicating the one or more sidelink paging times to the second wireless device; and waking up based on the one or more sidelink paging times to monitor for the sidelink paging from the second wireless device.

In Example 9, the method of any of Examples 1-8 further comprises: indicating a different paging time to the second wireless device after the one or more sidelink paging times expire.

In Example 10, the method of any of Examples 1-9 further includes that the one or more sidelink paging times are applied in place of a default sidelink paging cycle of the second wireless device.

Example 11 is an apparatus for wireless communication at a first wireless device, comprising: means for indicating one or more sidelink paging times to a second wireless device for paging between the first wireless device and the second wireless device; means for performing discontinuous reception; and means for monitoring for sidelink paging from the second wireless device based on the one or more sidelink paging times indicated to the second wireless device.

In Example 12, the apparatus of Example 11 further comprises means to perform the method of any of Examples 2-10.

Example 13 is an apparatus for wireless communication at a first wireless device, comprising: a memory; and at least one processor coupled to the memory, the memory and at least one processor being configured to perform the method of any of Examples 1-10.

Example 14 is a non-transitory computer-readable medium storing computer executable code for wireless communication at a first wireless device, the code when executed by a processor cause the processor to perform the method of any of Examples 1-10.

Example 15 is a method of wireless communication at a first wireless device, comprising: receiving an indication of one or more sidelink paging times from a second wireless device; and monitoring for a sidelink paging from the second wireless device based on the one or more sidelink paging times.

In Example 16, the method of Example 15 further includes that the one or more sidelink paging times include a duration and the first wireless device refrains from paging the second wireless device during the duration.

In Example 17, the method of Example 15 or Example 16 further includes that the second wireless device indicates multiple sidelink paging times and the first wireless device monitors for the sidelink paging from the first wireless device based on each of the multiple sidelink paging times.

In Example 18, the method of any of Examples 15-17 further includes that the second wireless device indicates a single paging time.

In Example 19, the method of any of Examples 15-18 further includes that the one or more sidelink paging times are non-periodic.

In Example 20, the method of any of Examples 15-19 further includes that the one or more sidelink paging times include a duration, wherein the first wireless device repeats monitoring for sidelink paging based on the duration for a defined number of times.

In Example 21, the method of any of Examples 15-20 further comprises: transmitting a sidelink page to the second wireless device in a paging occasion based on the one or more sidelink paging times.

In Example 22, the method of any of Examples 15-21 further comprises: receiving a sidelink page from the second wireless device in a paging occasion based on the one or more sidelink paging times.

In Example 23, the method of any of Examples 15-22 further comprises: entering into an idle mode or a sleep mode after receiving the one or more sidelink paging times from the second wireless device; and waking up based on the one or more sidelink paging times to monitor for the sidelink paging from the second wireless device.

In Example 24, the method of any of Examples 15-23 further comprises: receiving a different paging time from the second wireless device after the one or more sidelink paging times expire.

In Example 25, the method of any of Examples 15-24 further comprises:

applying the one or more sidelink paging time in place of a default sidelink paging cycle of the first wireless device.

Example 26 is an apparatus for wireless communication at a first wireless device, comprises: means for receiving an indication of one or more sidelink paging times from a second wireless device; and means for monitoring for a sidelink paging from the second wireless device based on the one or more sidelink paging times.

In Example 27, the apparatus of Example 26 further comprises means to perform the method of any of Examples 16-25.

Example 28 is an apparatus for wireless communication at a first wireless device, comprises: a memory; and at least one processor coupled to the memory, the memory and at least one processor being configured to perform the method of any of Examples 15-25.

Example 29 is a non-transitory computer-readable medium storing computer executable code for wireless communication at a first wireless device, the code when executed by a processor cause the processor to perform the method of any of Examples 15-25.

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 described 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 described 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. ”

Claims

A method of wireless communication at a first wireless device, comprising:

indicating one or more sidelink paging times to a second wireless device for paging between the first wireless device and the second wireless device;

performing discontinuous reception; and

monitoring for sidelink paging from the second wireless device based on the one or more sidelink paging times indicated to the second wireless device.
The method of claim 1, wherein each of the one or more sidelink paging times comprises a duration and the first wireless device does not monitor for the sidelink paging from the second wireless device during the duration between paging occasions.
The method of claim 2, wherein the first wireless device indicates multiple sidelink paging times and monitors for the sidelink paging from the second wireless device based on each of the multiple sidelink paging times.
The method of claim 2, wherein the first wireless device indicates a single paging time.
The method of claim 1, wherein the one or more sidelink paging times are non-periodic.
The method of claim 1, wherein the one or more sidelink paging times include a duration, wherein the first wireless device repeats monitoring for sidelink paging based on the duration for a defined number of times.
The method of claim 1, further comprising:

transmitting a sidelink page to the second wireless device in a paging occasion based on the one or more sidelink paging times.
The method of claim 1, further comprising:

entering into an idle mode or a sleep mode after indicating the one or more sidelink paging times to the second wireless device; and

waking up based on the one or more sidelink paging times to monitor for the sidelink paging from the second wireless device.
The method of claim 1, further comprising:

indicating a different paging time to the second wireless device after the one or more sidelink paging times expire.
The method of claim 1, wherein the one or more sidelink paging times are applied in place of a default sidelink paging cycle of the second wireless device.
An apparatus for wireless communication at a first wireless device, comprising:

means for indicating one or more sidelink paging times to a second wireless device for paging between the first wireless device and the second wireless device;

means for performing discontinuous reception; and

means for monitoring for sidelink paging from the second wireless device based on the one or more sidelink paging times indicated to the second wireless device.
The apparatus of claim 11, further comprising means for performing the method of any of claims 2-10.
An apparatus for wireless communication at a first wireless device, comprising:

a memory; and

at least one processor coupled to the memory, the memory and at least one processor being configured to perform the method of any of claims 1-10.
A non-transitory computer-readable medium storing computer executable code for wireless communication at a first wireless device, the code when executed by a processor cause the processor to perform the method of any of claims 1-10.
A method of wireless communication at a first wireless device, comprising:

receiving an indication of one or more sidelink paging times from a second wireless device; and

monitoring for a sidelink paging from the second wireless device based on the one or more sidelink paging times.
The method of claim 15, wherein the one or more sidelink paging times include a duration and the first wireless device refrains from paging the second wireless device during the duration.
The method of claim 16, wherein the second wireless device indicates multiple sidelink paging times and the first wireless device monitors for the sidelink paging from the first wireless device based on each of the multiple sidelink paging times.
The method of claim 16, wherein the second wireless device indicates a single paging time.
The method of claim 15, wherein the one or more sidelink paging times are non-periodic.
The method of claim 15, wherein the one or more sidelink paging times include a duration, wherein the first wireless device repeats monitoring for the sidelink paging based on the duration for a defined number of times.
The method of claim 15, further comprising:

transmitting a sidelink page to the second wireless device in a paging occasion based on the one or more sidelink paging times.
The method of claim 15, further comprising:

receiving a sidelink page from the second wireless device in a paging occasion based on the one or more sidelink paging times.
The method of claim 15, further comprising:

entering into an idle mode or a sleep mode after receiving the one or more sidelink paging times from the second wireless device; and

waking up based on the one or more sidelink paging times to monitor for the sidelink paging from the second wireless device.
The method of claim 15, further comprising:

receiving a different paging time from the second wireless device after the one or more sidelink paging times expire.
The method of claim 15, further comprising:

applying the one or more sidelink paging times in place of a default sidelink paging cycle of the first wireless device.
An apparatus for wireless communication at a first wireless device, comprising:

means for receiving an indication of one or more sidelink paging times from a second wireless device; and

means for monitoring for a sidelink paging from the second wireless device based on the one or more sidelink paging times.
The apparatus of claim 26, further comprising means for performing the method of any of claims 16-25.
An apparatus for wireless communication at a first wireless device, comprising:

a memory; and

at least one processor coupled to the memory, the memory and at least one processor being configured to perform the method of any of claims 15-25.
A non-transitory computer-readable medium storing computer executable code for wireless communication at a first wireless device, the code when executed by a processor cause the processor to perform the method of any of claims 15-25.