Transmission cancellation of a sidelink positioning reference signal

Abstract

Disclosed are techniques for wireless communication. Aspects of the disclosure are directed to cancellation of a sidelink positioning reference signal (SL-PRS) transmission on one or more SL-PRS resources in a SL-PRS resource pool for a position estimation session, such as a location services (LCS) session. In an aspect, the transmission cancellation of the SL-PRS transmission is based on detection that one or more session cancellation conditions associated with the position estimation session are satisfied. For example, the session cancellation condition(s) may indicate that one or more requirements of the position estimation session cannot be satisfied. Such aspects provide various technical advantages, such as reducing medium congestion and unnecessary power consumption attributable to unnecessary UE transmissions.

Description

Qualcomm Ref. No.2403139WO TRANSMISSION CANCELLATION OF A SIDELINK POSITIONING REFERENCE SIGNAL TECHNICAL FIELD

[0001] Aspects of the disclosure relate generally to wireless technologies. BACKGROUND

[0002] Wireless communication systems have developed through various generations, including a first-generation analog wireless phone service (1G), a second-generation (2G) digital wireless phone service (including interim 2.5G and 2.75G networks), a third-generation (3G) high speed data, Internet-capable wireless service and a fourth-generation (4G) service (e.g., Long Term Evolution (LTE) or WiMax). There are presently many different types of wireless communication systems in use, including cellular and personal communications service (PCS) systems. Examples of known cellular systems include the cellular analog advanced mobile phone system (AMPS), and digital cellular systems based on code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), the Global System for Mobile communications (GSM), etc.

[0003] A fifth generation (5G) wireless standard, referred to as New Radio (NR), enables higher data transfer speeds, greater numbers of connections, and better coverage, among other improvements. The 5G standard, according to the Next Generation Mobile Networks Alliance, is designed to provide higher data rates as compared to previous standards, more accurate positioning (e.g., based on reference signals for positioning (RS-P), such as downlink, uplink, or sidelink positioning reference signals (PRS)), radio frequency (RF) sensing, and other technical enhancements. These enhancements, as well as the use of higher frequency bands, advances in PRS processes and technology, and high-density deployments for 5G, enable highly accurate 5G-based sensing and positioning. SUMMARY

[0004] The following presents a simplified summary relating to one or more aspects disclosed herein. Thus, the following summary should not be considered an extensive overview relating to all contemplated aspects, nor should the following summary be considered to 1 QC2403139WOQualcomm Ref. No.2403139WO identify key or critical elements relating to all contemplated aspects or to delineate the scope associated with any particular aspect. Accordingly, the following summary has the sole purpose to present certain concepts relating to one or more aspects relating to the mechanisms disclosed herein in a simplified form to precede the detailed description presented below.

[0005] In an aspect, a method performed by a user equipment (UE) includes determining a set of sidelink positioning reference signal (SL-PRS) resources in a SL-PRS resource pool on which to transmit SL-PRS during a time window of a position estimation session; detecting that one or more session cancellation conditions associated with the position estimation session are satisfied; and canceling transmission of the SL-PRS on one or more SL-PRS resources of the set of SL-PRS resources based on the detection of the one or more session cancellation conditions and irrespective of an availability of the one or more SL-PRS resources.

[0006] In an aspect, a user equipment (UE) includes one or more memories; one or more transceivers; and one or more processors communicatively coupled to the one or more memories and the one or more transceivers, the one or more processors, either alone or in combination, configured to: determine a set of sidelink positioning reference signal (SL- PRS) resources in a SL-PRS resource pool on which to transmit SL-PRS during a time window of a position estimation session; detect that one or more session cancellation conditions associated with the position estimation session are satisfied; and cancel transmission of the SL-PRS on one or more SL-PRS resources of the set of SL-PRS resources based on the detection of the one or more session cancellation conditions and irrespective of an availability of the one or more SL-PRS resources.

[0007] In an aspect, a user equipment (UE) includes means for determining a set of sidelink positioning reference signal (SL-PRS) resources in a SL-PRS resource pool on which to transmit SL-PRS during a time window of a position estimation session; means for detecting that one or more session cancellation conditions associated with the position estimation session are satisfied; and means for canceling transmission of the SL-PRS on one or more SL-PRS resources of the set of SL-PRS resources based on the detection of the one or more session cancellation conditions and irrespective of an availability of the one or more SL-PRS resources. QC2403139WOQualcomm Ref. No.2403139WO

[0008] In an aspect, a non-transitory computer-readable medium storing computer-executable instructions that, when executed by a user equipment (UE), cause the UE to: determine a set of sidelink positioning reference signal (SL-PRS) resources in a SL-PRS resource pool on which to transmit SL-PRS during a time window of a position estimation session; detect that one or more session cancellation conditions associated with the position estimation session are satisfied; and cancel transmission of the SL-PRS on one or more SL-PRS resources of the set of SL-PRS resources based on the detection of the one or more session cancellation conditions and irrespective of an availability of the one or more SL-PRS resources.

[0009] Other objects and advantages associated with the aspects disclosed herein will be apparent to those skilled in the art based on the accompanying drawings and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The accompanying drawings are presented to aid in the description of various aspects of the disclosure and are provided solely for illustration of the aspects and not limitation thereof.

[0011] FIG. 1 illustrates an example wireless communications system, according to aspects of the disclosure.

[0012] FIGS.2A, 2B, and 2C illustrate example wireless network structures, according to aspects of the disclosure.

[0013] FIGS. 3A, 3B, and 3C are simplified block diagrams of several sample aspects of components that may be employed in a user equipment (UE), a base station, and a network entity, respectively, and configured to support communications as taught herein.

[0014] FIG. 4 is a diagram illustrating an example frame structure, according to aspects of the disclosure.

[0015] FIGS.5A and 5B illustrate various scenarios of interest for sidelink-only or joint Uu and sidelink positioning, according to aspects of the disclosure.

[0016] FIGS. 6A and 6B are diagrams of example sidelink slot structures with and without feedback resources, according to aspects of the disclosure.

[0017] FIGS. 7A to 7D are diagrams illustrating examples of resource pools for positioning, according to aspects of the disclosure. QC2403139WOQualcomm Ref. No.2403139WO

[0018] FIG. 8 illustrates the two resource allocation modes for transmissions on a sidelink, according to aspects of the disclosure.

[0019] FIG. 9 illustrates a location services (LCS) session, in accordance with aspects of the disclosure.

[0020] FIG. 10 illustrates a location services (LCS) session, in accordance with aspects of the disclosure.

[0021] FIG.11 illustrates an exemplary process of communications according to an aspect of the disclosure.

[0022] FIG. 12 illustrates an example implementation of the process of FIG. 11, in accordance with aspects of the disclosure. DETAILED DESCRIPTION

[0023] Aspects of the disclosure are provided in the following description and related drawings directed to various examples provided for illustration purposes. Alternate aspects may be devised without departing from the scope of the disclosure. Additionally, well-known elements of the disclosure will not be described in detail or will be omitted so as not to obscure the relevant details of the disclosure.

[0024] Various aspects relate generally to transmission cancellation of a sidelink positioning reference signal (SL-PRS). In some designs, when one or more sidelink positioning reference signal (SL-PRS) transmission (TX) user equipments (UE) of a location services (LCS) session do not manage to perform their required number of SL-PRS TXs (within a session time window), the session is rendered useless (no confidence in positioning accuracy). In addition, any SL-PRS TXs that managed to get transmitted within this useless session effectively only contributed to unnecessary medium congestion and unnecessary power consumption (for the TX UEs that managed to perform SL-PRS TXs).

[0025] Particular aspects of the subject matter described in this disclosure can be implemented to realize one or more of the following potential advantages. Aspects of the disclosure are directed to cancellation of a sidelink positioning reference signal (SL-PRS) transmission on one or more SL-PRS resources in a SL-PRS resource pool for a position estimation session, such as a location services (LCS) session. In an aspect, the transmission cancellation of the SL-PRS transmission is based on detection that one or more session cancellation conditions associated with the position estimation session are satisfied. For 4 QC2403139WOQualcomm Ref. No.2403139WO example, the session cancellation condition(s) may indicate that one or more requirements of the position estimation session cannot be satisfied. Such aspects provide various technical advantages, such as reducing medium congestion and unnecessary power consumption attributable to unnecessary UE transmissions.

[0026] The words “exemplary” and / or “example” are used herein to mean “serving as an example, instance, or illustration.” Any aspect described herein as “exemplary” and / or “example” is not necessarily to be construed as preferred or advantageous over other aspects. Likewise, the term “aspects of the disclosure” does not require that all aspects of the disclosure include the discussed feature, advantage or mode of operation.

[0027] Those of skill in the art will appreciate that the information and signals described below may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the description below may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof, depending in part on the particular application, in part on the desired design, in part on the corresponding technology, etc.

[0028] Further, many aspects are described in terms of sequences of actions to be performed by, for example, elements of a computing device. It will be recognized that various actions described herein can be performed by specific circuits (e.g., application specific integrated circuits (ASICs)), by program instructions being executed by one or more processors, or by a combination of both. Additionally, the sequence(s) of actions described herein can be considered to be embodied entirely within any form of non- transitory computer-readable storage medium having stored therein a corresponding set of computer instructions that, upon execution, would cause or instruct an associated processor of a device to perform the functionality described herein. Thus, the various aspects of the disclosure may be embodied in a number of different forms, all of which have been contemplated to be within the scope of the claimed subject matter. In addition, for each of the aspects described herein, the corresponding form of any such aspects may be described herein as, for example, “logic configured to” perform the described action.

[0029] As used herein, the terms “user equipment” (UE) and “base station” are not intended to be specific or otherwise limited to any particular radio access technology (RAT), unless otherwise noted. In general, a UE may be any wireless communication device (e.g., a QC2403139WOQualcomm Ref. No.2403139WO mobile phone, router, tablet computer, laptop computer, consumer asset locating device, wearable (e.g., smartwatch, glasses, augmented reality (AR) / virtual reality (VR) headset, etc.), vehicle (e.g., automobile, motorcycle, bicycle, etc.), Internet of Things (IoT) device, etc.) used by a user to communicate over a wireless communications network. A UE may be mobile or may (e.g., at certain times) be stationary, and may communicate with a radio access network (RAN). As used herein, the term “UE” may be referred to interchangeably as an “access terminal” or “AT,” a “client device,” a “wireless device,” a “subscriber device,” a “subscriber terminal,” a “subscriber station,” a “user terminal” or “UT,” a “mobile device,” a “mobile terminal,” a “mobile station,” or variations thereof. Generally, UEs can communicate with a core network via a RAN, and through the core network the UEs can be connected with external networks such as the Internet and with other UEs. Of course, other mechanisms of connecting to the core network and / or the Internet are also possible for the UEs, such as over wired access networks, wireless local area network (WLAN) networks (e.g., based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 specification, etc.) and so on.

[0030] A base station may operate according to one of several RATs in communication with UEs depending on the network in which it is deployed, and may be alternatively referred to as an access point (AP), a network node, a NodeB, an evolved NodeB (eNB), a next generation eNB (ng-eNB), a New Radio (NR) Node B (also referred to as a gNB or gNodeB), etc. A base station may be used primarily to support wireless access by UEs, including supporting data, voice, and / or signaling connections for the supported UEs. In some systems a base station may provide purely edge node signaling functions while in other systems it may provide additional control and / or network management functions. A communication link through which UEs can send signals to a base station is called an uplink (UL) channel (e.g., a reverse traffic channel, a reverse control channel, an access channel, etc.). A communication link through which the base station can send signals to UEs is called a downlink (DL) or forward link channel (e.g., a paging channel, a control channel, a broadcast channel, a forward traffic channel, etc.). As used herein the term traffic channel (TCH) can refer to either an uplink / reverse or downlink / forward traffic channel.

[0031] The term “base station” may refer to a single physical transmission-reception point (TRP) or to multiple physical TRPs that may or may not be co-located. For example, where the 6 QC2403139WOQualcomm Ref. No.2403139WO term “base station” refers to a single physical TRP, the physical TRP may be an antenna of the base station corresponding to a cell (or several cell sectors) of the base station. Where the term “base station” refers to multiple co-located physical TRPs, the physical TRPs may be an array of antennas (e.g., as in a multiple-input multiple-output (MIMO) system or where the base station employs beamforming) of the base station. Where the term “base station” refers to multiple non-co-located physical TRPs, the physical TRPs may be a distributed antenna system (DAS) (a network of spatially separated antennas connected to a common source via a transport medium) or a remote radio head (RRH) (a remote base station connected to a serving base station). Alternatively, the non-co-located physical TRPs may be the serving base station receiving the measurement report from the UE and a neighbor base station whose reference radio frequency (RF) signals the UE is measuring. Because a TRP is the point from which a base station transmits and receives wireless signals, as used herein, references to transmission from or reception at a base station are to be understood as referring to a particular TRP of the base station.

[0032] In some implementations that support positioning of UEs, a base station may not support wireless access by UEs (e.g., may not support data, voice, and / or signaling connections for UEs), but may instead transmit reference signals to UEs to be measured by the UEs, and / or may receive and measure signals transmitted by the UEs. Such a base station may be referred to as a positioning beacon (e.g., when transmitting signals to UEs) and / or as a location measurement unit (e.g., when receiving and measuring signals from UEs).

[0033] An “RF signal” comprises an electromagnetic wave of a given frequency that transports information through the space between a transmitter and a receiver. As used herein, a transmitter may transmit a single “RF signal” or multiple “RF signals” to a receiver. However, the receiver may receive multiple “RF signals” corresponding to each transmitted RF signal due to the propagation characteristics of RF signals through multipath channels. The same transmitted RF signal on different paths between the transmitter and receiver may be referred to as a “multipath” RF signal. As used herein, an RF signal may also be referred to as a “wireless signal” or simply a “signal” where it is clear from the context that the term “signal” refers to a wireless signal or an RF signal.

[0034] FIG.1 illustrates an example wireless communications system 100, according to aspects of the disclosure. The wireless communications system 100 (which may also be referred to as a wireless wide area network (WWAN)) may include various base stations 102 QC2403139WOQualcomm Ref. No.2403139WO (labeled “BS”) and various UEs 104. The base stations 102 may include macro cell base stations (high power cellular base stations) and / or small cell base stations (low power cellular base stations). In an aspect, the macro cell base stations may include eNBs and / or ng-eNBs where the wireless communications system 100 corresponds to an LTE network, or gNBs where the wireless communications system 100 corresponds to a NR network, or a combination of both, and the small cell base stations may include femtocells, picocells, microcells, etc.

[0035] The base stations 102 may collectively form a RAN and interface with a core network 170 (e.g., an evolved packet core (EPC) or a 5G core (5GC)) through backhaul links 122, and through the core network 170 to one or more location servers 172 (e.g., a location management function (LMF) or a secure user plane location (SUPL) location platform (SLP)). The location server(s) 172 may be part of core network 170 or may be external to core network 170. A location server 172 may be integrated with a base station 102. A UE 104 may communicate with a location server 172 directly or indirectly. For example, a UE 104 may communicate with a location server 172 via the base station 102 that is currently serving that UE 104. A UE 104 may also communicate with a location server 172 through another path, such as via an application server (not shown), via another network, such as via a wireless local area network (WLAN) access point (AP) (e.g., AP 150 described below), and so on. For signaling purposes, communication between a UE 104 and a location server 172 may be represented as an indirect connection (e.g., through the core network 170, etc.) or a direct connection (e.g., as shown via direct connection 128), with the intervening nodes (if any) omitted from a signaling diagram for clarity.

[0036] In addition to other functions, the base stations 102 may perform functions that relate to one or more of transferring 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, 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 with each other directly or indirectly (e.g., through the EPC / 5GC) over backhaul links 134, which may be wired or wireless. 8 QC2403139WOQualcomm Ref. No.2403139WO

[0037] 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. In an aspect, one or more cells may be supported by a base station 102 in each geographic coverage area 110. A “cell” is a logical communication entity used for communication with a base station (e.g., over some frequency resource, referred to as a carrier frequency, component carrier, carrier, band, or the like), and may be associated with an identifier (e.g., a physical cell identifier (PCI), an enhanced cell identifier (ECI), a virtual cell identifier (VCI), a cell global identifier (CGI), etc.) for distinguishing cells operating via the same or a different carrier frequency. In some cases, different cells may be configured according to different protocol types (e.g., machine-type communication (MTC), narrowband IoT (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access for different types of UEs. Because a cell is supported by a specific base station, the term “cell” may refer to either or both of the logical communication entity and the base station that supports it, depending on the context. In addition, because a TRP is typically the physical transmission point of a cell, the terms “cell” and “TRP” may be used interchangeably. In some cases, the term “cell” may also refer to a geographic coverage area of a base station (e.g., a sector), insofar as a carrier frequency can be detected and used for communication within some portion of geographic coverage areas 110.

[0038] While neighboring macro cell base station 102 geographic coverage areas 110 may partially overlap (e.g., in a handover region), some of the geographic coverage areas 110 may be substantially overlapped by a larger geographic coverage area 110. For example, a small cell base station 102' (labeled “SC” for “small cell”) may have a geographic coverage area 110' that substantially overlaps with the geographic coverage area 110 of one or more macro cell base stations 102. A network that includes both small cell and macro cell base stations may be known as a heterogeneous network. A heterogeneous network may also include home eNBs (HeNBs), which may provide service to a restricted group known as a closed subscriber group (CSG).

[0039] The communication links 120 between the base stations 102 and the UEs 104 may include uplink (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 MIMO antenna technology, 9 QC2403139WOQualcomm Ref. No.2403139WO including spatial multiplexing, beamforming, and / or transmit diversity. The communication links 120 may be through one or more carrier frequencies. Allocation of carriers may be asymmetric with respect to downlink and uplink (e.g., more or less carriers may be allocated for downlink than for uplink).

[0040] The wireless communications system 100 may further include a wireless local area network (WLAN) access point (AP) 150 in communication with WLAN stations (STAs) 152 via communication links 154 in an unlicensed frequency spectrum (e.g., 5 GHz). When communicating in an unlicensed frequency spectrum, the WLAN STAs 152 and / or the WLAN AP 150 may perform a clear channel assessment (CCA) or listen before talk (LBT) procedure prior to communicating in order to determine whether the channel is available.

[0041] The small cell base station 102' may operate in a licensed and / or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell base station 102' may employ LTE or NR technology and use the same 5 GHz unlicensed frequency spectrum as used by the WLAN AP 150. The small cell base station 102', employing LTE / 5G in an unlicensed frequency spectrum, may boost coverage to and / or increase capacity of the access network. NR in unlicensed spectrum may be referred to as NR-U. LTE in an unlicensed spectrum may be referred to as LTE-U, licensed assisted access (LAA), or MULTEFIRE®.

[0042] The wireless communications system 100 may further include a millimeter wave (mmW) base station 180 that may operate in mmW frequencies and / or near mmW frequencies in communication with a UE 182. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in this band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW / near mmW radio frequency band have high path loss and a relatively short range. The mmW base station 180 and the UE 182 may utilize beamforming (transmit and / or receive) over a mmW communication link 184 to compensate for the extremely high path loss and short range. Further, it will be appreciated that in alternative configurations, one or more base stations 102 may also transmit using mmW or near mmW and beamforming. QC2403139WOQualcomm Ref. No.2403139WO Accordingly, it will be appreciated that the foregoing illustrations are merely examples and should not be construed to limit the various aspects disclosed herein.

[0043] Transmit beamforming is a technique for focusing an RF signal in a specific direction. Traditionally, when a network node (e.g., a base station) broadcasts an RF signal, it broadcasts the signal in all directions (omni-directionally). With transmit beamforming, the network node determines where a given target device (e.g., a UE) is located (relative to the transmitting network node) and projects a stronger downlink RF signal in that specific direction, thereby providing a faster (in terms of data rate) and stronger RF signal for the receiving device(s). To change the directionality of the RF signal when transmitting, a network node can control the phase and relative amplitude of the RF signal at each of the one or more transmitters that are broadcasting the RF signal. For example, a network node may use an array of antennas (referred to as a “phased array” or an “antenna array”) that creates a beam of RF waves that can be “steered” to point in different directions, without actually moving the antennas. Specifically, the RF current from the transmitter is fed to the individual antennas with the correct phase relationship so that the radio waves from the separate antennas add together to increase the radiation in a desired direction, while canceling to suppress radiation in undesired directions.

[0044] Transmit beams may be quasi-co-located, meaning that they appear to the receiver (e.g., a UE) as having the same parameters, regardless of whether or not the transmitting antennas of the network node themselves are physically co-located. In NR, there are four types of quasi-co-location (QCL) relations. Specifically, a QCL relation of a given type means that certain parameters about a second reference RF signal on a second beam can be derived from information about a source reference RF signal on a source beam. Thus, if the source reference RF signal is QCL Type A, the receiver can use the source reference RF signal to estimate the Doppler shift, Doppler spread, average delay, and delay spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type B, the receiver can use the source reference RF signal to estimate the Doppler shift and Doppler spread of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QCL Type C, the receiver can use the source reference RF signal to estimate the Doppler shift and average delay of a second reference RF signal transmitted on the same channel. If the source reference RF signal is QC2403139WOQualcomm Ref. No.2403139WO QCL Type D, the receiver can use the source reference RF signal to estimate the spatial receive parameter of a second reference RF signal transmitted on the same channel.

[0045] In receive beamforming, the receiver uses a receive beam to amplify RF signals detected on a given channel. For example, the receiver can increase the gain setting and / or adjust the phase setting of an array of antennas in a particular direction to amplify (e.g., to increase the gain level of) the RF signals received from that direction. Thus, when a receiver is said to beamform in a certain direction, it means the beam gain in that direction is high relative to the beam gain along other directions, or the beam gain in that direction is the highest compared to the beam gain in that direction of all other receive beams available to the receiver. This results in a stronger received signal strength (e.g., reference signal received power (RSRP), reference signal received quality (RSRQ), signal-to- interference-plus-noise ratio (SINR), etc.) of the RF signals received from that direction.

[0046] Transmit and receive beams may be spatially related. A spatial relation means that parameters for a second beam (e.g., a transmit or receive beam) for a second reference signal can be derived from information about a first beam (e.g., a receive beam or a transmit beam) for a first reference signal. For example, a UE may use a particular receive beam to receive a reference downlink reference signal (e.g., synchronization signal block (SSB)) from a base station. The UE can then form a transmit beam for sending an uplink reference signal (e.g., sounding reference signal (SRS)) to that base station based on the parameters of the receive beam.

[0047] Note that a “downlink” beam may be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming the downlink beam to transmit a reference signal to a UE, the downlink beam is a transmit beam. If the UE is forming the downlink beam, however, it is a receive beam to receive the downlink reference signal. Similarly, an “uplink” beam may be either a transmit beam or a receive beam, depending on the entity forming it. For example, if a base station is forming the uplink beam, it is an uplink receive beam, and if a UE is forming the uplink beam, it is an uplink transmit beam.

[0048] 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). It should be understood that although a portion of FR1 is greater than QC2403139WOQualcomm Ref. No.2403139WO 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 TELECOMMUNICATION UNION® as a “millimeter wave” band.

[0049] 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 FR4a or FR4-1 (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.

[0050] 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, FR4-a or FR4-1, and / or FR5, or may be within the EHF band.

[0051] In a multi-carrier system, such as 5G, one of the carrier frequencies is referred to as the “primary carrier” or “anchor carrier” or “primary serving cell” or “PCell,” and the remaining carrier frequencies are referred to as “secondary carriers” or “secondary serving cells” or “SCells.” In carrier aggregation, the anchor carrier is the carrier operating on the primary frequency (e.g., FR1) utilized by a UE 104 / 182 and the cell in which the UE 104 / 182 either performs the initial radio resource control (RRC) connection establishment procedure or initiates the RRC connection re-establishment procedure. The primary carrier carries all common and UE-specific control channels, and may be a carrier in a licensed frequency (however, this is not always the case). A secondary carrier is a QC2403139WOQualcomm Ref. No.2403139WO carrier operating on a second frequency (e.g., FR2) that may be configured once the RRC connection is established between the UE 104 and the anchor carrier and that may be used to provide additional radio resources. In some cases, the secondary carrier may be a carrier in an unlicensed frequency. The secondary carrier may contain only necessary signaling information and signals, for example, those that are UE-specific may not be present in the secondary carrier, since both primary uplink and downlink carriers are typically UE- specific. This means that different UEs 104 / 182 in a cell may have different downlink primary carriers. The same is true for the uplink primary carriers. The network is able to change the primary carrier of any UE 104 / 182 at any time. This is done, for example, to balance the load on different carriers. Because a “serving cell” (whether a PCell or an SCell) corresponds to a carrier frequency / component carrier over which some base station is communicating, the term “cell,” “serving cell,” “component carrier,” “carrier frequency,” and the like can be used interchangeably.

[0052] For example, still referring to FIG. 1, one of the frequencies utilized by the macro cell base stations 102 may be an anchor carrier (or “PCell”) and other frequencies utilized by the macro cell base stations 102 and / or the mmW base station 180 may be secondary carriers (“SCells”). The simultaneous transmission and / or reception of multiple carriers enables the UE 104 / 182 to significantly increase its data transmission and / or reception rates. For example, two 20 MHz aggregated carriers in a multi-carrier system would theoretically lead to a two-fold increase in data rate (i.e., 40 MHz), compared to that attained by a single 20 MHz carrier.

[0053] The wireless communications system 100 may further include a UE 164 that may communicate with a macro cell base station 102 over a communication link 120 and / or the mmW base station 180 over a mmW communication link 184. For example, the macro cell base station 102 may support a PCell and one or more SCells for the UE 164 and the mmW base station 180 may support one or more SCells for the UE 164.

[0054] In some cases, the UE 164 and the UE 182 may be capable of sidelink communication. Sidelink-capable UEs (SL-UEs) may communicate with base stations 102 over communication links 120 using the Uu interface (i.e., the air interface between a UE and a base station). SL-UEs (e.g., UE 164, UE 182) may also communicate directly with each other over a wireless sidelink 160 using the PC5 interface (i.e., the air interface between sidelink-capable UEs). A wireless sidelink (or just “sidelink”) is an adaptation of the core 14 QC2403139WOQualcomm Ref. No.2403139WO cellular (e.g., LTE, NR) standard that allows direct communication between two or more UEs without the communication needing to go through a base station. Sidelink communication may be unicast or multicast, and may be used for device-to-device (D2D) media-sharing, vehicle-to-vehicle (V2V) communication, vehicle-to-everything (V2X) communication (e.g., cellular V2X (cV2X) communication, enhanced V2X (eV2X) communication, etc.), emergency rescue applications, etc. One or more of a group of SL- UEs utilizing sidelink communications may be within the geographic coverage area 110 of a base station 102. Other SL-UEs in such a group may be outside the geographic coverage area 110 of a base station 102 or be otherwise unable to receive transmissions from a base station 102. In some cases, groups of SL-UEs communicating via sidelink communications may utilize a one-to-many (1:M) system in which each SL-UE transmits to every other SL-UE in the group. In some cases, a base station 102 facilitates the scheduling of resources for sidelink communications. In other cases, sidelink communications are carried out between SL-UEs without the involvement of a base station 102.

[0055] In an aspect, the sidelink 160 may operate over a wireless communication medium of interest, which may be shared with other wireless communications between other vehicles and / or infrastructure access points, as well as other RATs. A “medium” may be composed of one or more time, frequency, and / or space communication resources (e.g., encompassing one or more channels across one or more carriers) associated with wireless communication between one or more transmitter / receiver pairs. In an aspect, the medium of interest may correspond to at least a portion of an unlicensed frequency band shared among various RATs. Although different licensed frequency bands have been reserved for certain communication systems (e.g., by a government entity such as the Federal Communications Commission (FCC) in the United States), these systems, in particular those employing small cell access points, have recently extended operation into unlicensed frequency bands such as the Unlicensed National Information Infrastructure (U-NII) band used by wireless local area network (WLAN) technologies, most notably IEEE 802.11x WLAN technologies generally referred to as “Wi-Fi.” Example systems of this type include different variants of CDMA systems, TDMA systems, FDMA systems, orthogonal FDMA (OFDMA) systems, single-carrier FDMA (SC-FDMA) systems, and so on. QC2403139WOQualcomm Ref. No.2403139WO

[0056] Note that although FIG. 1 only illustrates two of the UEs as SL-UEs (i.e., UEs 164 and 182), any of the illustrated UEs may be SL-UEs. Further, although only UE 182 was described as being capable of beamforming, any of the illustrated UEs, including UE 164, may be capable of beamforming. Where SL-UEs are capable of beamforming, they may beamform towards each other (i.e., towards other SL-UEs), towards other UEs (e.g., UEs 104), towards base stations (e.g., base stations 102, 180, small cell 102’, access point 150), etc. Thus, in some cases, UEs 164 and 182 may utilize beamforming over sidelink 160.

[0057] In the example of FIG.1, any of the illustrated UEs (shown in FIG.1 as a single UE 104 for simplicity) may receive signals 124 from one or more Earth orbiting space vehicles (SVs) 112 (e.g., satellites). In an aspect, the SVs 112 may be part of a satellite positioning system that a UE 104 can use as an independent source of location information. A satellite positioning system typically includes a system of transmitters (e.g., SVs 112) positioned to enable receivers (e.g., UEs 104) to determine their location on or above the Earth based, at least in part, on positioning signals (e.g., signals 124) received from the transmitters. Such a transmitter typically transmits a signal marked with a repeating pseudo-random noise (PN) code of a set number of chips. While typically located in SVs 112, transmitters may sometimes be located on ground-based control stations, base stations 102, and / or other UEs 104. A UE 104 may include one or more dedicated receivers specifically designed to receive signals 124 for deriving geo location information from the SVs 112.

[0058] In a satellite positioning system, the use of signals 124 can be augmented by various satellite-based augmentation systems (SBAS) that may be associated with or otherwise enabled for use with one or more global and / or regional navigation satellite systems. For example an SBAS may include an augmentation system(s) that provides integrity information, differential corrections, etc., such as the Wide Area Augmentation System (WAAS), the European Geostationary Navigation Overlay Service (EGNOS), the Multi- functional Satellite Augmentation System (MSAS), the Global Positioning System (GPS) Aided Geo Augmented Navigation or GPS and Geo Augmented Navigation system (GAGAN), and / or the like. Thus, as used herein, a satellite positioning system may include any combination of one or more global and / or regional navigation satellites associated with such one or more satellite positioning systems. 16 QC2403139WOQualcomm Ref. No.2403139WO

[0059] In an aspect, SVs 112 may additionally or alternatively be part of one or more non- terrestrial networks (NTNs). In an NTN, an SV 112 is connected to an earth station (also referred to as a ground station, NTN gateway, or gateway), which in turn is connected to an element in a 5G network, such as a modified base station 102 (without a terrestrial antenna) or a network node in a 5GC. This element would in turn provide access to other elements in the 5G network and ultimately to entities external to the 5G network, such as Internet web servers and other user devices. In that way, a UE 104 may receive communication signals (e.g., signals 124) from an SV 112 instead of, or in addition to, communication signals from a terrestrial base station 102.

[0060] The wireless communications system 100 may further include one or more UEs, such as UE 190, that connects indirectly to one or more communication networks via one or more device-to-device (D2D) peer-to-peer (P2P) links (referred to as “sidelinks”). In the example of FIG. 1, UE 190 has a D2D P2P link 192 with one of the UEs 104 connected to one of the base stations 102 (e.g., through which UE 190 may indirectly obtain cellular connectivity) and a D2D P2P link 194 with WLAN STA 152 connected to the WLAN AP 150 (through which UE 190 may indirectly obtain WLAN-based Internet connectivity). In an example, the D2D P2P links 192 and 194 may be supported with any well-known D2D RAT, such as LTE Direct (LTE-D), WI-FI DIRECT®, BLUETOOTH®, and so on.

[0061] FIG.2A illustrates an example wireless network structure 200. For example, a 5GC 210 (also referred to as a Next Generation Core (NGC)) can be viewed functionally as control plane (C-plane) functions 214 (e.g., UE registration, authentication, network access, gateway selection, etc.) and user plane (U-plane) functions 212, (e.g., UE gateway function, access to data networks, IP routing, etc.) which operate cooperatively to form the core network. User plane interface (NG-U) 213 and control plane interface (NG-C) 215 connect the gNB 222 to the 5GC 210 and specifically to the user plane functions 212 and control plane functions 214, respectively. In an additional configuration, an ng-eNB 224 may also be connected to the 5GC 210 via NG-C 215 to the control plane functions 214 and NG-U 213 to user plane functions 212. Further, ng-eNB 224 may directly communicate with gNB 222 via a backhaul connection 223. In some configurations, a Next Generation RAN (NG-RAN) 220 may have one or more gNBs 222, while other configurations include one or more of both ng-eNBs 224 and gNBs 222. Either (or both) QC2403139WOQualcomm Ref. No.2403139WO gNB 222 or ng-eNB 224 may communicate with one or more UEs 204 (e.g., any of the UEs described herein).

[0062] Another optional aspect may include a location server 230, which may be in communication with the 5GC 210 to provide location assistance for UE(s) 204. The location server 230 can be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternately may each correspond to a single server. The location server 230 can be configured to support one or more location services for UEs 204 that can connect to the location server 230 via the core network, 5GC 210, and / or via the Internet (not illustrated). Further, the location server 230 may be integrated into a component of the core network, or alternatively may be external to the core network (e.g., a third party server, such as an original equipment manufacturer (OEM) server or service server).

[0063] FIG. 2B illustrates another example wireless network structure 240. A 5GC 260 (which may correspond to 5GC 210 in FIG. 2A) can be viewed functionally as control plane functions, provided by an access and mobility management function (AMF) 264, and user plane functions, provided by a user plane function (UPF) 262, which operate cooperatively to form the core network (i.e., 5GC 260). The functions of the AMF 264 include registration management, connection management, reachability management, mobility management, lawful interception, transport for session management (SM) messages between one or more UEs 204 (e.g., any of the UEs described herein) and a session management function (SMF) 266, transparent proxy services for routing SM messages, access authentication and access authorization, transport for short message service (SMS) messages between the UE 204 and the short message service function (SMSF) (not shown), and security anchor functionality (SEAF). The AMF 264 also interacts with an authentication server function (AUSF) (not shown) and the UE 204, and receives the intermediate key that was established as a result of the UE 204 authentication process. In the case of authentication based on a UMTS (universal mobile telecommunications system) subscriber identity module (USIM), the AMF 264 retrieves the security material from the AUSF. The functions of the AMF 264 also include security context management (SCM). The SCM receives a key from the SEAF that it uses to derive access-network specific keys. The functionality of the AMF 264 also includes location 18 QC2403139WOQualcomm Ref. No.2403139WO services management for regulatory services, transport for location services messages between the UE 204 and a location management function (LMF) 270 (which acts as a location server 230), transport for location services messages between the NG-RAN 220 and the LMF 270, evolved packet system (EPS) bearer identifier allocation for interworking with the EPS, and UE 204 mobility event notification. In addition, the AMF 264 also supports functionalities for non-3GPP® (Third Generation Partnership Project) access networks.

[0064] Functions of the UPF 262 include acting as an anchor point for intra / inter-RAT mobility (when applicable), acting as an external protocol data unit (PDU) session point of interconnect to a data network (not shown), providing packet routing and forwarding, packet inspection, user plane policy rule enforcement (e.g., gating, redirection, traffic steering), lawful interception (user plane collection), traffic usage reporting, quality of service (QoS) handling for the user plane (e.g., uplink / downlink rate enforcement, reflective QoS marking in the downlink), uplink traffic verification (service data flow (SDF) to QoS flow mapping), transport level packet marking in the uplink and downlink, downlink packet buffering and downlink data notification triggering, and sending and forwarding of one or more “end markers” to the source RAN node. The UPF 262 may also support transfer of location services messages over a user plane between the UE 204 and a location server, such as an SLP 272.

[0065] The functions of the SMF 266 include session management, UE Internet protocol (IP) address allocation and management, selection and control of user plane functions, configuration of traffic steering at the UPF 262 to route traffic to the proper destination, control of part of policy enforcement and QoS, and downlink data notification. The interface over which the SMF 266 communicates with the AMF 264 is referred to as the N11 interface.

[0066] Another optional aspect may include an LMF 270, which may be in communication with the 5GC 260 to provide location assistance for UEs 204. The LMF 270 can be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternately may each correspond to a single server. The LMF 270 can be configured to support one or more location services for UEs 204 that can connect to the LMF 270 via the core network, 5GC 260, and / or via the Internet (not 19 QC2403139WOQualcomm Ref. No.2403139WO 20 illustrated). The SLP 272 may support similar functions to the LMF 270, but whereas the LMF 270 may communicate with the AMF 264, NG-RAN 220, and UEs 204 over a control plane (e.g., using interfaces and protocols intended to convey signaling messages and not voice or data), the SLP 272 may communicate with UEs 204 and external clients (e.g., third-party server 274) over a user plane (e.g., using protocols intended to carry voice and / or data like the transmission control protocol (TCP) and / or IP).

[0067] Yet another optional aspect may include a third-party server 274, which may be in communication with the LMF 270, the SLP 272, the 5GC 260 (e.g., via the AMF 264 and / or the UPF 262), the NG-RAN 220, and / or the UE 204 to obtain location information (e.g., a location estimate) for the UE 204. As such, in some cases, the third-party server 274 may be referred to as a location services (LCS) client or an external client. The third- party server 274 can be implemented as a plurality of separate servers (e.g., physically separate servers, different software modules on a single server, different software modules spread across multiple physical servers, etc.), or alternately may each correspond to a single server.

[0068] User plane interface 263 and control plane interface 265 connect the 5GC 260, and specifically the UPF 262 and AMF 264, respectively, to one or more gNBs 222 and / or ng-eNBs 224 in the NG-RAN 220. The interface between gNB(s) 222 and / or ng-eNB(s) 224 and the AMF 264 is referred to as the “N2” interface, and the interface between gNB(s) 222 and / or ng-eNB(s) 224 and the UPF 262 is referred to as the “N3” interface. The gNB(s) 222 and / or ng-eNB(s) 224 of the NG-RAN 220 may communicate directly with each other via backhaul connections 223, referred to as the “Xn-C” interface. One or more of gNBs 222 and / or ng-eNBs 224 may communicate with one or more UEs 204 over a wireless interface, referred to as the “Uu” interface.

[0069] The functionality of a gNB 222 may be divided between a gNB central unit (gNB-CU) 226, one or more gNB distributed units (gNB-DUs) 228, and one or more gNB radio units (gNB-RUs) 229. A gNB-CU 226 is a logical node that includes the base station functions of transferring user data, mobility control, radio access network sharing, positioning, session management, and the like, except for those functions allocated exclusively to the gNB-DU(s) 228. More specifically, the gNB-CU 226 generally host the radio resource control (RRC), service data adaptation protocol (SDAP), and packet data convergence protocol (PDCP) protocols of the gNB 222. A gNB-DU 228 is a logical node that QC2403139WOQualcomm Ref. No.2403139WO generally hosts the radio link control (RLC) and medium access control (MAC) layer of the gNB 222. Its operation is controlled by the gNB-CU 226. One gNB-DU 228 can support one or more cells, and one cell is supported by only one gNB-DU 228. The interface 232 between the gNB-CU 226 and the one or more gNB-DUs 228 is referred to as the “F1” interface. The physical (PHY) layer functionality of a gNB 222 is generally hosted by one or more standalone gNB-RUs 229 that perform functions such as power amplification and signal transmission / reception. The interface between a gNB-DU 228 and a gNB-RU 229 is referred to as the “Fx” interface. Thus, a UE 204 communicates with the gNB-CU 226 via the RRC, SDAP, and PDCP layers, with a gNB-DU 228 via the RLC and MAC layers, and with a gNB-RU 229 via the PHY layer.

[0070] Deployment of communication systems, such as 5G NR systems, may be arranged in multiple manners with various components or constituent parts. In a 5G NR system, or network, a network node, a network entity, a mobility element of a network, a RAN node, a core network node, a network element, or a network equipment, such as a base station, or one or more units (or one or more components) performing base station functionality, may be implemented in an aggregated or disaggregated architecture. For example, a base station (such as a Node B (NB), evolved NB (eNB), NR base station, 5G NB, AP, TRP, cell, etc.) may be implemented as an aggregated base station (also known as a standalone base station or a monolithic base station) or a disaggregated base station.

[0071] An aggregated base station may be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node. A disaggregated base station may be configured to utilize a protocol stack that is physically or logically distributed among two or more units (such as one or more central or centralized units (CUs), one or more distributed units (DUs), or one or more radio units (RUs)). In some aspects, a CU may be implemented within a RAN node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed throughout one or multiple other RAN nodes. The DUs may be implemented to communicate with one or more RUs. Each of the CU, DU and RU also can be implemented as virtual units, i.e., a virtual central unit (VCU), a virtual distributed unit (VDU), or a virtual radio unit (VRU).

[0072] Base station-type operation or network design may consider aggregation characteristics of base station functionality. For example, disaggregated base stations may be utilized in an integrated access backhaul (IAB) network, an open radio access network (O-RAN QC2403139WOQualcomm Ref. No.2403139WO (such as the network configuration sponsored by the O-RAN ALLIANCE®)), or a virtualized radio access network (vRAN, also known as a cloud radio access network (C- RAN)). Disaggregation may include distributing functionality across two or more units at various physical locations, as well as distributing functionality for at least one unit virtually, which can enable flexibility in network design. The various units of the disaggregated base station, or disaggregated RAN architecture, can be configured for wired or wireless communication with at least one other unit.

[0073] FIG. 2C illustrates an example disaggregated base station architecture 250, according to aspects of the disclosure. The disaggregated base station architecture 250 may include one or more central units (CUs) 280 (e.g., gNB-CU 226) that can communicate directly with a core network 267 (e.g., 5GC 210, 5GC 260) via a backhaul link, or indirectly with the core network 267 through one or more disaggregated base station units (such as a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) 259 via an E2 link, or a Non-Real Time (Non-RT) RIC 257 associated with a Service Management and Orchestration (SMO) Framework 255, or both). A CU 280 may communicate with one or more DUs 285 (e.g., gNB-DUs 228) via respective midhaul links, such as an F1 interface. The DUs 285 may communicate with one or more radio units (RUs) 287 (e.g., gNB-RUs 229) via respective fronthaul links. The RUs 287 may communicate with respective UEs 204 via one or more radio frequency (RF) access links. In some implementations, the UE 204 may be simultaneously served by multiple RUs 287.

[0074] Each of the units, i.e., the CUs 280, the DUs 285, the RUs 287, as well as the Near-RT RICs 259, the Non-RT RICs 257 and the SMO Framework 255, may include one or more interfaces or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communication interfaces of the units, can be configured to communicate with one or more of the other units via the transmission medium. For example, the units can include a wired interface configured to receive or transmit signals over a wired transmission medium to one or more of the other units. Additionally, the units can include a wireless interface, which may include a receiver, a transmitter or transceiver (such as a RF transceiver), configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units. QC2403139WOQualcomm Ref. No.2403139WO 23

[0075] In some aspects, the CU 280 may host one or more higher layer control functions. Such control functions can include RRC, PDCP, service data adaptation protocol (SDAP), or the like. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 280. The CU 280 may be configured to handle user plane functionality (i.e., Central Unit – User Plane (CU- UP)), control plane functionality (i.e., Central Unit – Control Plane (CU-CP)), or a combination thereof. In some implementations, the CU 280 can be logically split into one or more CU-UP units and one or more CU-CP units. The CU-UP unit can communicate bidirectionally with the CU-CP unit via an interface, such as the E1 interface when implemented in an O-RAN configuration. The CU 280 can be implemented to communicate with the DU 285, as necessary, for network control and signaling.

[0076] The DU 285 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 287. In some aspects, the DU 285 may host one or more of a RLC layer, a MAC layer, and one or more high PHY layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, or the like) depending, at least in part, on a functional split, such as those defined by the 3rd Generation Partnership Project (3GPP®). In some aspects, the DU 285 may further host one or more low PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 285, or with the control functions hosted by the CU 280.

[0077] Lower-layer functionality can be implemented by one or more RUs 287. In some deployments, an RU 287, controlled by a DU 285, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT), inverse FFT (iFFT), digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like), or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU(s) 287 can be implemented to handle over the air (OTA) communication with one or more UEs 204. In some implementations, real-time and non-real-time aspects of control and user plane communication with the RU(s) 287 can be controlled by the corresponding DU 285. In some scenarios, this configuration can enable the DU(s) 285 QC2403139WOQualcomm Ref. No.2403139WO 24 and the CU 280 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.

[0078] The SMO Framework 255 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 255 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements which may be managed via an operations and maintenance interface (such as an O1 interface). For virtualized network elements, the SMO Framework 255 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 269) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an O2 interface). Such virtualized network elements can include, but are not limited to, CUs 280, DUs 285, RUs 287 and Near-RT RICs 259. In some implementations, the SMO Framework 255 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 261, via an O1 interface. Additionally, in some implementations, the SMO Framework 255 can communicate directly with one or more RUs 287 via an O1 interface. The SMO Framework 255 also may include a Non-RT RIC 257 configured to support functionality of the SMO Framework 255.

[0079] The Non-RT RIC 257 may be configured to include a logical function that enables non- real-time control and optimization of RAN elements and resources, artificial intelligence / machine learning (AI / ML) workflows including model training and updates, or policy-based guidance of applications / features in the Near-RT RIC 259. The Non-RT RIC 257 may be coupled to or communicate with (such as via an A1 interface) the Near- RT RIC 259. The Near-RT RIC 259 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 280, one or more DUs 285, or both, as well as an O-eNB, with the Near-RT RIC 259.

[0080] In some implementations, to generate AI / ML models to be deployed in the Near-RT RIC 259, the Non-RT RIC 257 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 259 and may be received at the SMO Framework 255 or the Non-RT RIC 257 from non-network QC2403139WOQualcomm Ref. No.2403139WO data sources or from network functions. In some examples, the Non-RT RIC 257 or the Near-RT RIC 259 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 257 may monitor long-term trends and patterns for performance and employ AI / ML models to perform corrective actions through the SMO Framework 255 (such as reconfiguration via O1) or via creation of RAN management policies (such as A1 policies).

[0081] FIGS. 3A, 3B, and 3C illustrate several example components (represented by corresponding blocks) that may be incorporated into a UE 302 (which may correspond to any of the UEs described herein), a base station 304 (which may correspond to any of the base stations described herein), and a network entity 306 (which may correspond to or embody any of the network functions described herein, including the location server 230 and the LMF 270, or alternatively may be independent from the NG-RAN 220 and / or 5GC 210 / 260 infrastructure depicted in FIGS. 2A and 2B, such as a private network) to support the operations described herein. It will be appreciated that these components may be implemented in different types of apparatuses in different implementations (e.g., in an ASIC, in a system-on-chip (SoC), etc.). The illustrated components may also be incorporated into other apparatuses in a communication system. For example, other apparatuses in a system may include components similar to those described to provide similar functionality. Also, a given apparatus may contain one or more of the components. For example, an apparatus may include multiple transceiver components that enable the apparatus to operate on multiple carriers and / or communicate via different technologies.

[0082] The UE 302 and the base station 304 each include one or more wireless wide area network (WWAN) transceivers 310 and 350, respectively, providing means for communicating (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for refraining from transmitting, etc.) via one or more wireless communication networks (not shown), such as an NR network, an LTE network, a GSM network, and / or the like. The WWAN transceivers 310 and 350 may each be connected to one or more antennas 316 and 356, respectively, for communicating with other network nodes, such as other UEs, access points, base stations (e.g., eNBs, gNBs), etc., via at least one designated RAT (e.g., NR, LTE, GSM, etc.) over a wireless communication medium of interest (e.g., some set of time / frequency resources in a particular frequency spectrum). The WWAN transceivers 310 and 350 may be variously configured for transmitting and QC2403139WOQualcomm Ref. No.2403139WO encoding signals 318 and 358 (e.g., messages, indications, information, and so on), respectively, and, conversely, for receiving and decoding signals 318 and 358 (e.g., messages, indications, information, pilots, and so on), respectively, in accordance with the designated RAT. Specifically, the WWAN transceivers 310 and 350 include one or more transmitters 314 and 354, respectively, for transmitting and encoding signals 318 and 358, respectively, and one or more receivers 312 and 352, respectively, for receiving and decoding signals 318 and 358, respectively.

[0083] The UE 302 and the base station 304 each also include, at least in some cases, one or more short-range wireless transceivers 320 and 360, respectively. The short-range wireless transceivers 320 and 360 may be connected to one or more antennas 326 and 366, respectively, and provide means for communicating (e.g., means for transmitting, means for receiving, means for measuring, means for tuning, means for refraining from transmitting, etc.) with other network nodes, such as other UEs, access points, base stations, etc., via at least one designated RAT (e.g., Wi-Fi, LTE Direct, BLUETOOTH®, ZIGBEE®, Z-WAVE®, PC5, dedicated short-range communications (DSRC), wireless access for vehicular environments (WAVE), near-field communication (NFC), ultra- wideband (UWB), etc.) over a wireless communication medium of interest. The short- range wireless transceivers 320 and 360 may be variously configured for transmitting and encoding signals 328 and 368 (e.g., messages, indications, information, and so on), respectively, and, conversely, for receiving and decoding signals 328 and 368 (e.g., messages, indications, information, pilots, and so on), respectively, in accordance with the designated RAT. Specifically, the short-range wireless transceivers 320 and 360 include one or more transmitters 324 and 364, respectively, for transmitting and encoding signals 328 and 368, respectively, and one or more receivers 322 and 362, respectively, for receiving and decoding signals 328 and 368, respectively. As specific examples, the short-range wireless transceivers 320 and 360 may be Wi-Fi transceivers, BLUETOOTH® transceivers, ZIGBEE® and / or Z-WAVE® transceivers, NFC transceivers, UWB transceivers, or vehicle-to-vehicle (V2V) and / or vehicle-to- everything (V2X) transceivers.

[0084] The UE 302 and the base station 304 also include, at least in some cases, satellite signal interfaces 330 and 370, which each include one or more satellite signal receivers 332 and 372, respectively, and may optionally include one or more satellite signal transmitters 334 QC2403139WOQualcomm Ref. No.2403139WO 27 and 374, respectively. In some cases, the base station 304 may be a terrestrial base station that may communicate with space vehicles (e.g., space vehicles 112) via the satellite signal interface 370. In other cases, the base station 304 may be a space vehicle (or other non-terrestrial entity) that uses the satellite signal interface 370 to communicate with terrestrial networks and / or other space vehicles.

[0085] The satellite signal receivers 332 and 372 may be connected to one or more antennas 336 and 376, respectively, and may provide means for receiving and / or measuring satellite positioning / communication signals 338 and 378, respectively. Where the satellite signal receiver(s) 332 and 372 are satellite positioning system receivers, the satellite positioning / communication signals 338 and 378 may be global positioning system (GPS) signals, global navigation satellite system (GLONASS) signals, Galileo signals, Beidou signals, Indian Regional Navigation Satellite System (NAVIC), Quasi-Zenith Satellite System (QZSS) signals, etc. Where the satellite signal receiver(s) 332 and 372 are non- terrestrial network (NTN) receivers, the satellite positioning / communication signals 338 and 378 may be communication signals (e.g., carrying control and / or user data) originating from a 5G network. The satellite signal receiver(s) 332 and 372 may comprise any suitable hardware and / or software for receiving and processing satellite positioning / communication signals 338 and 378, respectively. The satellite signal receiver(s) 332 and 372 may request information and operations as appropriate from the other systems, and, at least in some cases, perform calculations to determine locations of the UE 302 and the base station 304, respectively, using measurements obtained by any suitable satellite positioning system algorithm.

[0086] The optional satellite signal transmitter(s) 334 and 374, when present, may be connected to the one or more antennas 336 and 376, respectively, and may provide means for transmitting satellite positioning / communication signals 338 and 378, respectively. Where the satellite signal transmitter(s) 374 are satellite positioning system transmitters, the satellite positioning / communication signals 378 may be GPS signals, GLONASS® signals, Galileo signals, Beidou signals, NAVIC, QZSS signals, etc. Where the satellite signal transmitter(s) 334 and 374 are NTN transmitters, the satellite positioning / communication signals 338 and 378 may be communication signals (e.g., carrying control and / or user data) originating from a 5G network. The satellite signal transmitter(s) 334 and 374 may comprise any suitable hardware and / or software for QC2403139WOQualcomm Ref. No.2403139WO 28 transmitting satellite positioning / communication signals 338 and 378, respectively. The satellite signal transmitter(s) 334 and 374 may request information and operations as appropriate from the other systems.

[0087] The base station 304 and the network entity 306 each include one or more network transceivers 380 and 390, respectively, providing means for communicating (e.g., means for transmitting, means for receiving, etc.) with other network entities (e.g., other base stations 304, other network entities 306). For example, the base station 304 may employ the one or more network transceivers 380 to communicate with other base stations 304 or network entities 306 over one or more wired or wireless backhaul links. As another example, the network entity 306 may employ the one or more network transceivers 390 to communicate with one or more base station 304 over one or more wired or wireless backhaul links, or with other network entities 306 over one or more wired or wireless core network interfaces.

[0088] A transceiver may be configured to communicate over a wired or wireless link. A transceiver (whether a wired transceiver or a wireless transceiver) includes transmitter circuitry (e.g., transmitters 314, 324, 354, 364) and receiver circuitry (e.g., receivers 312, 322, 352, 362). A transceiver may be an integrated device (e.g., embodying transmitter circuitry and receiver circuitry in a single device) in some implementations, may comprise separate transmitter circuitry and separate receiver circuitry in some implementations, or may be embodied in other ways in other implementations. The transmitter circuitry and receiver circuitry of a wired transceiver (e.g., network transceivers 380 and 390 in some implementations) may be coupled to one or more wired network interface ports. Wireless transmitter circuitry (e.g., transmitters 314, 324, 354, 364) may include or be coupled to a plurality of antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, that permits the respective apparatus (e.g., UE 302, base station 304) to perform transmit “beamforming,” as described herein. Similarly, wireless receiver circuitry (e.g., receivers 312, 322, 352, 362) may include or be coupled to a plurality of antennas (e.g., antennas 316, 326, 356, 366), such as an antenna array, that permits the respective apparatus (e.g., UE 302, base station 304) to perform receive beamforming, as described herein. In an aspect, the transmitter circuitry and receiver circuitry may share the same plurality of antennas (e.g., antennas 316, 326, 356, 366), such that the respective apparatus can only receive or transmit at a given time, not both at the same time. A wireless transceiver (e.g., QC2403139WOQualcomm Ref. No.2403139WO WWAN transceivers 310 and 350, short-range wireless transceivers 320 and 360) may also include a network listen module (NLM) or the like for performing various measurements.

[0089] As used herein, the various wireless transceivers (e.g., transceivers 310, 320, 350, and 360, and network transceivers 380 and 390 in some implementations) and wired transceivers (e.g., network transceivers 380 and 390 in some implementations) may generally be characterized as “a transceiver,” “at least one transceiver,” or “one or more transceivers.” As such, whether a particular transceiver is a wired or wireless transceiver may be inferred from the type of communication performed. For example, backhaul communication between network devices or servers will generally relate to signaling via a wired transceiver, whereas wireless communication between a UE (e.g., UE 302) and a base station (e.g., base station 304) will generally relate to signaling via a wireless transceiver.

[0090] The UE 302, the base station 304, and the network entity 306 also include other components that may be used in conjunction with the operations as disclosed herein. The UE 302, the base station 304, and the network entity 306 include one or more processors 342, 384, and 394, respectively, for providing functionality relating to, for example, wireless communication, and for providing other processing functionality. The processors 342, 384, and 394 may therefore provide means for processing, such as means for determining, means for calculating, means for receiving, means for transmitting, means for indicating, etc. In an aspect, the processors 342, 384, and 394 may include, for example, one or more general purpose processors, multi-core processors, central processing units (CPUs), ASICs, digital signal processors (DSPs), field programmable gate arrays (FPGAs), other programmable logic devices or processing circuitry, or various combinations thereof.

[0091] The UE 302, the base station 304, and the network entity 306 include memory circuitry implementing memories 340, 386, and 396 (e.g., each including a memory device), respectively, for maintaining information (e.g., information indicative of reserved resources, thresholds, parameters, and so on). The memories 340, 386, and 396 may therefore provide means for storing, means for retrieving, means for maintaining, etc. In some cases, the UE 302, the base station 304, and the network entity 306 may include SL-PRS component 348, 388, and 398, respectively. The SL-PRS component 348, 388, QC2403139WOQualcomm Ref. No.2403139WO and 398 may be hardware circuits that are part of or coupled to the processors 342, 384, and 394, respectively, that, when executed, cause the UE 302, the base station 304, and the network entity 306 to perform the functionality described herein. In other aspects, the SL-PRS component 348, 388, and 398 may be external to the processors 342, 384, and 394 (e.g., part of a modem processing system, integrated with another processing system, etc.). Alternatively, the SL-PRS component 348, 388, and 398 may be memory modules stored in the memories 340, 386, and 396, respectively, that, when executed by the processors 342, 384, and 394 (or a modem processing system, another processing system, etc.), cause the UE 302, the base station 304, and the network entity 306 to perform the functionality described herein. FIG. 3A illustrates possible locations of the SL-PRS component 348, which may be, for example, part of the one or more WWAN transceivers 310, the memory 340, the one or more processors 342, or any combination thereof, or may be a standalone component. FIG. 3B illustrates possible locations of the SL-PRS component 388, which may be, for example, part of the one or more WWAN transceivers 350, the memory 386, the one or more processors 384, or any combination thereof, or may be a standalone component. FIG. 3C illustrates possible locations of the SL-PRS component 398, which may be, for example, part of the one or more network transceivers 390, the memory 396, the one or more processors 394, or any combination thereof, or may be a standalone component.

[0092] The UE 302 may include one or more sensors 344 coupled to the one or more processors 342 to provide means for sensing or detecting movement and / or orientation information that is independent of motion data derived from signals received by the one or more WWAN transceivers 310, the one or more short-range wireless transceivers 320, and / or the satellite signal interface 330. By way of example, the sensor(s) 344 may include an accelerometer (e.g., a micro-electrical mechanical systems (MEMS) device), a gyroscope, a geomagnetic sensor (e.g., a compass), an altimeter (e.g., a barometric pressure altimeter), and / or any other type of movement detection sensor. Moreover, the sensor(s) 344 may include a plurality of different types of devices and combine their outputs in order to provide motion information. For example, the sensor(s) 344 may use a combination of a multi-axis accelerometer and orientation sensors to provide the ability to compute positions in two-dimensional (2D) and / or three-dimensional (3D) coordinate systems. QC2403139WOQualcomm Ref. No.2403139WO

[0093] In addition, the UE 302 includes a user interface 346 providing means for providing indications (e.g., audible and / or visual indications) to a user and / or for receiving user input (e.g., upon user actuation of a sensing device such a keypad, a touch screen, a microphone, and so on). Although not shown, the base station 304 and the network entity 306 may also include user interfaces.

[0094] Referring to the one or more processors 384 in more detail, in the downlink, IP packets from the network entity 306 may be provided to the processor 384. The one or more processors 384 may implement functionality for an RRC layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The one or more processors 384 may provide RRC layer functionality associated with broadcasting of system information (e.g., master information block (MIB), system information blocks (SIBs)), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), inter-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 PDUs, error correction through automatic repeat request (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, scheduling information reporting, error correction, priority handling, and logical channel prioritization.

[0095] The transmitter 354 and the receiver 352 may implement Layer-1 (L1) 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 transmitter 354 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 QC2403139WOQualcomm Ref. No.2403139WO streams. Each stream may then be mapped to an orthogonal frequency division multiplexing (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 symbol stream is spatially precoded to produce multiple spatial streams. Channel estimates from a channel estimator 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 UE 302. Each spatial stream may then be provided to one or more different antennas 356. The transmitter 354 may modulate an RF carrier with a respective spatial stream for transmission.

[0096] At the UE 302, the receiver 312 receives a signal through its respective antenna(s) 316. The receiver 312 recovers information modulated onto an RF carrier and provides the information to the one or more processors 342. The transmitter 314 and the receiver 312 implement Layer-1 functionality associated with various signal processing functions. The receiver 312 may perform spatial processing on the information to recover any spatial streams destined for the UE 302. If multiple spatial streams are destined for the UE 302, they may be combined by the receiver 312 into a single OFDM symbol stream. The receiver 312 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 304. These soft decisions may be based on channel estimates computed by a channel estimator. The soft decisions are then decoded and de-interleaved to recover the data and control signals that were originally transmitted by the base station 304 on the physical channel. The data and control signals are then provided to the one or more processors 342, which implements Layer-3 (L3) and Layer-2 (L2) functionality.

[0097] In the downlink, the one or more processors 342 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, and control signal processing to recover IP packets from the core network. The one or more processors 342 are also responsible for error detection. QC2403139WOQualcomm Ref. No.2403139WO

[0098] Similar to the functionality described in connection with the downlink transmission by the base station 304, the one or more processors 342 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 transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through hybrid automatic repeat request (HARQ), priority handling, and logical channel prioritization.

[0099] Channel estimates derived by the channel estimator from a reference signal or feedback transmitted by the base station 304 may be used by the transmitter 314 to select the appropriate coding and modulation schemes, and to facilitate spatial processing. The spatial streams generated by the transmitter 314 may be provided to different antenna(s) 316. The transmitter 314 may modulate an RF carrier with a respective spatial stream for transmission.

[0100] The uplink transmission is processed at the base station 304 in a manner similar to that described in connection with the receiver function at the UE 302. The receiver 352 receives a signal through its respective antenna(s) 356. The receiver 352 recovers information modulated onto an RF carrier and provides the information to the one or more processors 384.

[0101] In the uplink, the one or more processors 384 provides demultiplexing between transport and logical channels, packet reassembly, deciphering, header decompression, control signal processing to recover IP packets from the UE 302. IP packets from the one or more processors 384 may be provided to the core network. The one or more processors 384 are also responsible for error detection.

[0102] For convenience, the UE 302, the base station 304, and / or the network entity 306 are shown in FIGS.3A, 3B, and 3C as including various components that may be configured according to the various examples described herein. It will be appreciated, however, that the illustrated components may have different functionality in different designs. In QC2403139WOQualcomm Ref. No.2403139WO particular, various components in FIGS. 3A to 3C are optional in alternative configurations and the various aspects include configurations that may vary due to design choice, costs, use of the device, or other considerations. For example, in case of FIG.3A, a particular implementation of UE 302 may omit the WWAN transceiver(s) 310 (e.g., a wearable device or tablet computer or personal computer (PC) or laptop may have Wi-Fi and / or BLUETOOTH® capability without cellular capability), or may omit the short- range wireless transceiver(s) 320 (e.g., cellular-only, etc.), or may omit the satellite signal interface 330, or may omit the sensor(s) 344, and so on. In another example, in case of FIG. 3B, a particular implementation of the base station 304 may omit the WWAN transceiver(s) 350 (e.g., a Wi-Fi “hotspot” access point without cellular capability), or may omit the short-range wireless transceiver(s) 360 (e.g., cellular-only, etc.), or may omit the satellite signal interface 370, and so on. For brevity, illustration of the various alternative configurations is not provided herein, but would be readily understandable to one skilled in the art.

[0103] The various components of the UE 302, the base station 304, and the network entity 306 may be communicatively coupled to each other over data buses 308, 382, and 392, respectively. In an aspect, the data buses 308, 382, and 392 may form, or be part of, a communication interface of the UE 302, the base station 304, and the network entity 306, respectively. For example, where different logical entities are embodied in the same device (e.g., gNB and location server functionality incorporated into the same base station 304), the data buses 308, 382, and 392 may provide communication between them.

[0104] The components of FIGS.3A, 3B, and 3C may be implemented in various ways. In some implementations, the components of FIGS. 3A, 3B, and 3C may be implemented in one or more circuits such as, for example, one or more processors and / or one or more ASICs (which may include one or more processors). Here, each circuit may use and / or incorporate at least one memory component for storing information or executable code used by the circuit to provide this functionality. For example, some or all of the functionality represented by blocks 310 to 346 may be implemented by processor and memory component(s) of the UE 302 (e.g., by execution of appropriate code and / or by appropriate configuration of processor components). Similarly, some or all of the functionality represented by blocks 350 to 388 may be implemented by processor and memory component(s) of the base station 304 (e.g., by execution of appropriate code QC2403139WOQualcomm Ref. No.2403139WO and / or by appropriate configuration of processor components). Also, some or all of the functionality represented by blocks 390 to 398 may be implemented by processor and memory component(s) of the network entity 306 (e.g., by execution of appropriate code and / or by appropriate configuration of processor components). For simplicity, various operations, acts, and / or functions are described herein as being performed “by a UE,” “by a base station,” “by a network entity,” etc. However, as will be appreciated, such operations, acts, and / or functions may actually be performed by specific components or combinations of components of the UE 302, base station 304, network entity 306, etc., such as the processors 342, 384, 394, the transceivers 310, 320, 350, and 360, the memories 340, 386, and 396, the SL-PRS component 348, 388, and 398, etc.

[0105] In some designs, the network entity 306 may be implemented as a core network component. In other designs, the network entity 306 may be distinct from a network operator or operation of the cellular network infrastructure (e.g., NG RAN 220 and / or 5GC 210 / 260). For example, the network entity 306 may be a component of a private network that may be configured to communicate with the UE 302 via the base station 304 or independently from the base station 304 (e.g., over a non-cellular communication link, such as Wi-Fi).

[0106] Various frame structures may be used to support downlink and uplink transmissions between network nodes (e.g., base stations and UEs). FIG.4 is a diagram 400 illustrating an example frame structure, according to aspects of the disclosure. The frame structure may be a downlink or uplink frame structure. Other wireless communications technologies may have different frame structures and / or different channels.

[0107] LTE, and in some cases NR, utilizes orthogonal frequency-division multiplexing (OFDM) on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink. Unlike LTE, however, NR has an option to use OFDM on the uplink as well. OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, etc. Each subcarrier may be modulated with data. In general, modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM. The spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system bandwidth. For example, the spacing of the subcarriers may be 15 kilohertz (kHz) and the minimum resource allocation (resource block) may be 12 subcarriers (or QC2403139WOQualcomm Ref. No.2403139WO 180 kHz). Consequently, the nominal fast Fourier transform (FFT) size may be equal to 128, 256, 512, 1024, or 2048 for system bandwidth of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz (i.e., 6 resource blocks), and there may be 1, 2, 4, 8, or 16 subbands for system bandwidth of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0108] LTE supports a single numerology (subcarrier spacing (SCS), symbol length, etc.). In contrast, NR may support multiple numerologies (μ), for example, subcarrier spacings of 15 kHz (μ=0), 30 kHz (μ=1), 60 kHz (μ=2), 120 kHz (μ=3), and 240 kHz (μ=4) or greater may be available. In each subcarrier spacing, there are 14 symbols per slot. For 15 kHz SCS (μ=0), there is one slot per subframe, 10 slots per frame, the slot duration is 1 millisecond (ms), the symbol duration is 66.7 microseconds (μs), and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 50. For 30 kHz SCS (μ=1), there are two slots per subframe, 20 slots per frame, the slot duration is 0.5 ms, the symbol duration is 33.3 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 100. For 60 kHz SCS (μ=2), there are four slots per subframe, 40 slots per frame, the slot duration is 0.25 ms, the symbol duration is 16.7 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 200. For 120 kHz SCS (μ=3), there are eight slots per subframe, 80 slots per frame, the slot duration is 0.125 ms, the symbol duration is 8.33 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 400. For 240 kHz SCS (μ=4), there are 16 slots per subframe, 160 slots per frame, the slot duration is 0.0625 ms, the symbol duration is 4.17 μs, and the maximum nominal system bandwidth (in MHz) with a 4K FFT size is 800.

[0109] In the example of FIG.4, a numerology of 15 kHz is used. Thus, in the time domain, a 10 ms frame is divided into 10 equally sized subframes of 1 ms each, and each subframe includes one time slot. In FIG. 4, time is represented horizontally (on the X axis) with time increasing from left to right, while frequency is represented vertically (on the Y axis) with frequency increasing (or decreasing) from bottom to top.

[0110] A resource grid may be used to represent time slots, each time slot including one or more time-concurrent resource blocks (RBs) (also referred to as physical RBs (PRBs)) in the frequency domain. The resource grid is further divided into multiple resource elements (REs). An RE may correspond to one symbol length in the time domain and one subcarrier in the frequency domain. In the numerology of FIG.4, for a normal cyclic prefix, an RB QC2403139WOQualcomm Ref. No.2403139WO may contain 12 consecutive subcarriers in the frequency domain and seven consecutive symbols in the time domain, for a total of 84 REs. For an extended cyclic prefix, an RB may contain 12 consecutive subcarriers in the frequency domain and six consecutive symbols in the time domain, for a total of 72 REs. The number of bits carried by each RE depends on the modulation scheme.

[0111] Some of the REs may carry reference (pilot) signals (RS). The reference signals may include positioning reference signals (PRS), tracking reference signals (TRS), phase tracking reference signals (PTRS), cell-specific reference signals (CRS), channel state information reference signals (CSI-RS), demodulation reference signals (DMRS), primary synchronization signals (PSS), secondary synchronization signals (SSS), synchronization signal blocks (SSBs), sounding reference signals (SRS), etc., depending on whether the illustrated frame structure is used for uplink or downlink communication. FIG.4 illustrates example locations of REs carrying a reference signal (labeled “R”).

[0112] A collection of resource elements (REs) that are used for transmission of PRS is referred to as a “PRS resource.” The collection of resource elements can span multiple PRBs in the frequency domain and ‘N’ (such as 1 or more) consecutive symbol(s) within a slot in the time domain. In a given OFDM symbol in the time domain, a PRS resource occupies consecutive PRBs in the frequency domain.

[0113] The transmission of a PRS resource within a given PRB has a particular comb size (also referred to as the “comb density”). A comb size ‘N’ represents the subcarrier spacing (or frequency / tone spacing) within each symbol of a PRS resource configuration. Specifically, for a comb size ‘N,’ PRS are transmitted in every Nth subcarrier of a symbol of a PRB. For example, for comb-4, for each symbol of the PRS resource configuration, REs corresponding to every fourth subcarrier (such as subcarriers 0, 4, 8) are used to transmit PRS of the PRS resource. Currently, comb sizes of comb-2, comb-4, comb-6, and comb-12 are supported for DL-PRS. FIG. 4 illustrates an example PRS resource configuration for comb-4 (which spans four symbols). That is, the locations of the shaded REs (labeled “R”) indicate a comb-4 PRS resource configuration.

[0114] Currently, a DL-PRS resource may span 2, 4, 6, or 12 consecutive symbols within a slot with a fully frequency-domain staggered pattern. A DL-PRS resource can be configured in any higher layer configured downlink or flexible (FL) symbol of a slot. There may be a constant energy per resource element (EPRE) for all REs of a given DL-PRS resource. QC2403139WOQualcomm Ref. No.2403139WO The following are the frequency offsets from symbol to symbol for comb sizes 2, 4, 6, and 12 over 2, 4, 6, and 12 symbols. 2-symbol comb-2: {0, 1}; 4-symbol comb-2: {0, 1, 0, 1}; 6-symbol comb-2: {0, 1, 0, 1, 0, 1}; 12-symbol comb-2: {0, 1, 0, 1, 0, 1, 0, 1, 0, 1, 0, 1}; 4-symbol comb-4: {0, 2, 1, 3} (as in the example of FIG. 4); 12-symbol comb-4: {0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3}; 6-symbol comb-6: {0, 3, 1, 4, 2, 5}; 12-symbol comb-6: {0, 3, 1, 4, 2, 5, 0, 3, 1, 4, 2, 5}; and 12-symbol comb-12: {0, 6, 3, 9, 1, 7, 4, 10, 2, 8, 5, 11}.

[0115] A “PRS resource set” is a set of PRS resources used for the transmission of PRS signals, where each PRS resource has a PRS resource ID. In addition, the PRS resources in a PRS resource set are associated with the same TRP. A PRS resource set is identified by a PRS resource set ID and is associated with a particular TRP (identified by a TRP ID). In addition, the PRS resources in a PRS resource set have the same periodicity, a common muting pattern configuration, and the same repetition factor (such as “PRS- ResourceRepetitionFactor”) across slots. The periodicity is the time from the first repetition of the first PRS resource of a first PRS instance to the same first repetition of the same first PRS resource of the next PRS instance. The periodicity may have a length selected from 2^μ*{4, 5, 8, 10, 16, 20, 32, 40, 64, 80, 160, 320, 640, 1280, 2560, 5120, 10240} slots, with μ = 0, 1, 2, 3. The repetition factor may have a length selected from {1, 2, 4, 6, 8, 16, 32} slots.

[0116] A PRS resource ID in a PRS resource set is associated with a single beam (or beam ID) transmitted from a single TRP (where a TRP may transmit one or more beams). That is, each PRS resource of a PRS resource set may be transmitted on a different beam, and as such, a “PRS resource,” or simply “resource,” also can be referred to as a “beam.” Note that this does not have any implications on whether the TRPs and the beams on which PRS are transmitted are known to the UE.

[0117] A “PRS instance” or “PRS occasion” is one instance of a periodically repeated time window (such as a group of one or more consecutive slots) where PRS are expected to be transmitted. A PRS occasion also may be referred to as a “PRS positioning occasion,” a “PRS positioning instance, a “positioning occasion,” “a positioning instance,” a “positioning repetition,” or simply an “occasion,” an “instance,” or a “repetition.”

[0118] A “positioning frequency layer” (also referred to simply as a “frequency layer”) is a collection of one or more PRS resource sets across one or more TRPs that have the same QC2403139WOQualcomm Ref. No.2403139WO values for certain parameters. Specifically, the collection of PRS resource sets has the same subcarrier spacing and cyclic prefix (CP) type (meaning all numerologies supported for the physical downlink shared channel (PDSCH) are also supported for PRS), the same Point A, the same value of the downlink PRS bandwidth, the same start PRB (and center frequency), and the same comb-size. The Point A parameter takes the value of the parameter “ARFCN-ValueNR” (where “ARFCN” stands for “absolute radio-frequency channel number”) and is an identifier / code that specifies a pair of physical radio channel used for transmission and reception. The downlink PRS bandwidth may have a granularity of four PRBs, with a minimum of 24 PRBs and a maximum of 272 PRBs. Currently, up to four frequency layers have been defined, and up to two PRS resource sets may be configured per TRP per frequency layer.

[0119] The concept of a frequency layer is somewhat like the concept of component carriers and bandwidth parts (BWPs), but different in that component carriers and BWPs are used by one base station (or a macro cell base station and a small cell base station) to transmit data channels, while frequency layers are used by several (usually three or more) base stations to transmit PRS. A UE may indicate the number of frequency layers it can support when it sends the network its positioning capabilities, such as during an LTE positioning protocol (LPP) session. For example, a UE may indicate whether it can support one or four positioning frequency layers.

[0120] Note that the terms “positioning reference signal” and “PRS” generally refer to specific reference signals that are used for positioning in NR and LTE systems. However, as used herein, the terms “positioning reference signal” and “PRS” may also refer to any type of reference signal that can be used for positioning, such as but not limited to, PRS as defined in LTE and NR, TRS, PTRS, CRS, CSI-RS, DMRS, PSS, SSS, SSB, SRS, UL-PRS, etc. In addition, the terms “positioning reference signal” and “PRS” may refer to downlink, uplink, or sidelink positioning reference signals, unless otherwise indicated by the context. If needed to further distinguish the type of PRS, a downlink positioning reference signal may be referred to as a “DL-PRS,” an uplink positioning reference signal (e.g., an SRS-for-positioning, PTRS) may be referred to as an “UL-PRS,” and a sidelink positioning reference signal may be referred to as an “SL-PRS.” In addition, for signals that may be transmitted in the downlink, uplink, and / or sidelink (e.g., DMRS), the signals QC2403139WOQualcomm Ref. No.2403139WO may be prepended with “DL,” “UL,” or “SL” to distinguish the direction. For example, “UL-DMRS” is different from “DL-DMRS.”

[0121] In an aspect, the reference signal carried on the REs labeled “R” in FIG. 4 may be SRS. SRS transmitted by a UE may be used by a base station to obtain the channel state information (CSI) for the transmitting UE. CSI describes how an RF signal propagates from the UE to the base station and represents the combined effect of scattering, fading, and power decay with distance. The system uses the SRS for resource scheduling, link adaptation, massive MIMO, beam management, etc.

[0122] A collection of REs that are used for transmission of SRS is referred to as an “SRS resource,” and may be identified by the parameter “SRS-ResourceId.” The collection of resource elements can span multiple PRBs in the frequency domain and ‘N’ (e.g., one or more) consecutive symbol(s) within a slot in the time domain. In a given OFDM symbol, an SRS resource occupies one or more consecutive PRBs. An “SRS resource set” is a set of SRS resources used for the transmission of SRS signals, and is identified by an SRS resource set ID (“SRS-ResourceSetId”).

[0123] The transmission of SRS resources within a given PRB has a particular comb size (also referred to as the “comb density”). A comb size ‘N’ represents the subcarrier spacing (or frequency / tone spacing) within each symbol of an SRS resource configuration. Specifically, for a comb size ‘N,’ SRS are transmitted in every Nth subcarrier of a symbol of a PRB. For example, for comb-4, for each symbol of the SRS resource configuration, REs corresponding to every fourth subcarrier (such as subcarriers 0, 4, 8) are used to transmit SRS of the SRS resource. In the example of FIG.4, the illustrated SRS is comb- 4 over four symbols. That is, the locations of the shaded SRS REs indicate a comb-4 SRS resource configuration.

[0124] Currently, an SRS resource may span 1, 2, 4, 8, or 12 consecutive symbols within a slot with a comb size of comb-2, comb-4, or comb-8. The following are the frequency offsets from symbol to symbol for the SRS comb patterns that are currently supported.1-symbol comb-2: {0}; 2-symbol comb-2: {0, 1}; 2-symbol comb-4: {0, 2}; 4-symbol comb-2: {0, 1, 0, 1}; 4-symbol comb-4: {0, 2, 1, 3} (as in the example of FIG. 4); 8-symbol comb-4: {0, 2, 1, 3, 0, 2, 1, 3}; 12-symbol comb-4: {0, 2, 1, 3, 0, 2, 1, 3, 0, 2, 1, 3}; 4-symbol comb-8: {0, 4, 2, 6}; 8-symbol comb-8: {0, 4, 2, 6, 1, 5, 3, 7}; and 12-symbol comb-8: {0, 4, 2, 6, 1, 5, 3, 7, 0, 4, 2, 6}. 40 QC2403139WOQualcomm Ref. No.2403139WO

[0125] Generally, as noted above, a UE transmits SRS to enable the receiving base station (either the serving base station or a neighboring base station) to measure the channel quality (i.e., CSI) between the UE and the base station. However, SRS can also be specifically configured as uplink positioning reference signals for uplink-based positioning procedures, such as uplink time difference of arrival (UL-TDOA), round-trip-time (RTT), uplink angle-of-arrival (UL-AoA), etc. As used herein, the term “SRS” may refer to SRS configured for channel quality measurements or SRS configured for positioning purposes. The former may be referred to herein as “SRS-for-communication” and / or the latter may be referred to as “SRS for positioning” or “positioning SRS” when needed to distinguish the two types of SRS.

[0126] Several enhancements over the previous definition of SRS may be available for SRS for positioning (also referred to as “UL-PRS”), such as a new staggered pattern within an SRS resource (except for single-symbol / comb-2), a new comb type for SRS, new sequences for SRS, a higher number of SRS resource sets per component carrier, and a higher number of SRS resources per component carrier. In addition, the parameters “SpatialRelationInfo” and “PathLossReference” are to be configured based on a downlink reference signal or SSB from a neighboring TRP. Further still, one SRS resource may be transmitted outside the active bandwidth part (BWP), and one SRS resource may span across multiple component carriers. Also, SRS may be configured in RRC connected state and only transmitted within an active BWP. Further, there may be no frequency hopping, no repetition factor, a single antenna port, and new lengths for SRS (e.g., 8 and 12 symbols). There also may be open-loop power control and not closed-loop power control, and comb-8 (i.e., an SRS transmitted every eighth subcarrier in the same symbol) may be used. Lastly, the UE may transmit through the same transmit beam from multiple SRS resources for UL-AoA. These features may be configured through RRC higher layer signaling (and potentially triggered or activated through a MAC control element (MAC- CE) or downlink control information (DCI)).

[0127] NR supports, or enables, various sidelink positioning techniques. FIG. 5A illustrates various scenarios of interest for sidelink-only or joint Uu and sidelink positioning, according to aspects of the disclosure. In scenario 510, at least one peer UE with a known location can improve the Uu-based positioning (e.g., multi-cell round-trip-time (RTT), downlink time difference of arrival (DL-TDOA), etc.) of a target UE by providing an 41 QC2403139WOQualcomm Ref. No.2403139WO additional anchor (e.g., using sidelink RTT (SL-RTT)). In scenario 520, a low-end (e.g., reduced capacity, or “RedCap”) target UE may obtain the assistance of premium UEs to determine its location using, e.g., sidelink positioning and ranging procedures with the premium UEs. Compared to the low-end UE, the premium UEs may have more capabilities, such as more sensors, a faster processor, more memory, more antenna elements, higher transmit power capability, access to additional frequency bands, or any combination thereof. In scenario 530, a relay UE (e.g., with a known location) participates in the positioning estimation of a remote UE without performing uplink positioning reference signal (PRS) transmission over the Uu interface. Scenario 540 illustrates the joint positioning of multiple UEs. Specifically, in scenario 540, two UEs with unknown positions can be jointly located in non-line-of-sight (NLOS) conditions by utilizing constraints from nearby UEs.

[0128] FIG. 5B illustrates additional scenarios of interest for sidelink-only or joint Uu and sidelink positioning, according to aspects of the disclosure. In scenario 550, UEs used for public safety (e.g., by police, firefighters, and / or the like) may perform peer-to-peer (P2P) positioning and ranging for public safety and other uses. For example, in scenario 550, the public safety UEs may be out of coverage of a network and determine a location or a relative distance and a relative position among the public safety UEs using sidelink positioning techniques. Similarly, scenario 560 shows multiple UEs that are out of coverage and determine a location or a relative distance and a relative position using sidelink positioning techniques, such as SL-RTT.

[0129] Sidelink communication takes place in transmission or reception resource pools. In the frequency domain, the minimum resource allocation unit is a sub-channel (e.g., a collection of consecutive PRBs in the frequency domain). In the time domain, resource allocation is in one slot intervals. However, some slots are not available for sidelink, and some slots contain feedback resources. In addition, sidelink resources can be (pre)configured to occupy fewer than the 14 symbols of a slot.

[0130] Sidelink resources are configured at the radio resource control (RRC) layer. The RRC configuration can be by pre-configuration (e.g., preloaded on the UE) or configuration (e.g., from a serving base station).

[0131] NR sidelinks support hybrid automatic repeat request (HARQ) retransmission. FIG. 6A is a diagram 600 of an example slot structure without feedback resources, according to QC2403139WOQualcomm Ref. No.2403139WO aspects of the disclosure. In the example of FIG.6A, time is represented horizontally and frequency is represented vertically. In the time domain, the length of each block is one orthogonal frequency division multiplexing (OFDM) symbol, and the 14 symbols make up a slot. In the frequency domain, the height of each block is one sub-channel. Currently, the (pre)configured sub-channel size can be selected from the set of {10, 15, 20, 25, 50, 75, 100} physical resource blocks (PRBs).

[0132] For a sidelink slot, the first symbol is a repetition of the preceding symbol and is used for automatic gain control (AGC) setting. This is illustrated in FIG. 6A by the vertical and horizontal hashing. As shown in FIG. 6A, for sidelink, the physical sidelink control channel (PSCCH) and the physical sidelink shared channel (PSSCH) are transmitted in the same slot. Similar to the physical downlink control channel (PDCCH), the PSCCH carries control information about sidelink resource allocation and descriptions about sidelink data transmitted to the UE. Likewise, similar to the physical downlink shared channel (PDSCH), the PSSCH carries user data for the UE. In the example of FIG. 6A, the PSCCH occupies half the bandwidth of the sub-channel and only three symbols. Finally, a gap symbol is present after the PSSCH.

[0133] FIG.6B is a diagram 650 of an example slot structure with feedback resources, according to aspects of the disclosure. In the example of FIG. 6B, time is represented horizontally and frequency is represented vertically. In the time domain, the length of each block is one OFDM symbol, and the 14 symbols make up a slot. In the frequency domain, the height of each block is one sub-channel.

[0134] The slot structure illustrated in FIG. 6B is similar to the slot structure illustrated in FIG. 6A, except that the slot structure illustrated in FIG. 6B includes feedback resources. Specifically, two symbols at the end of the slot have been dedicated to the physical sidelink feedback channel (PSFCH). The first PSFCH symbol is a repetition of the second PSFCH symbol for AGC setting. In addition to the gap symbol after the PSSCH, there is a gap symbol after the two PSFCH symbols. Currently, resources for the PSFCH can be configured with a periodicity selected from the set of {0, 1, 2, 4} slots.

[0135] FIG. 7A is a diagram 700 illustrating an example of a resource pool for positioning configured within a sidelink resource pool for communication (i.e., a shared resource pool), according to aspects of the disclosure. In the example of FIG. 7A, time is represented horizontally and frequency is represented vertically. In the time domain, the QC2403139WOQualcomm Ref. No.2403139WO length of each block is an orthogonal frequency division multiplexing (OFDM) symbol, and the 14 symbols make up a slot. In the frequency domain, the height of each block is a sub-channel.

[0136] In the example of FIG.7A, the entire slot (except for the first and last symbols) can be a resource pool for sidelink communication. That is, any of the symbols other than the first and last can be allocated for sidelink communication. However, a resource pool for positioning (RP-P) is allocated in the last four pre-gap symbols of the slot. As such, non- sidelink positioning data, such as user data (PSSCH), channel state information reference signal (CSI-RS), and control information, can only be transmitted in the first eight post- automatic gain control (AGC) symbols and not in the last four pre-gap symbols to prevent a collision with the configured RP-P. The non-sidelink positioning data that would otherwise be transmitted in the last four pre-gap symbols can be punctured or muted, or the non-sidelink data that would normally span more than the eight post-AGC symbols can be rate matched to fit into the eight post-AGC symbols.

[0137] Sidelink positioning reference signals (SL-PRS) have been defined to enable sidelink positioning procedures among UEs. Like a downlink PRS (DL-PRS), a SL-PRS resource is composed of one or more resource elements (i.e., one OFDM symbol in the time domain and one subcarrier in the frequency domain). SL-PRS resources have been designed with a comb-based pattern to enable fast Fourier transform (FFT)-based processing at the receiver. SL-PRS resources are composed of unstaggered, or only partially staggered, resource elements in the frequency domain to provide small time of arrival (TOA) uncertainty and reduced overhead of each SL-PRS resource. SL-PRS may also be associated with specific RP-Ps (e.g., certain SL-PRS may be allocated in certain RP-Ps). SL-PRS have also been defined with intra-slot repetition (not shown in FIG.7A) to allow for combining gains (if needed). There may also be inter-UE coordination of RP- Ps to provide for dynamic SL-PRS and data multiplexing while minimizing SL-PRS collisions.

[0138] FIGS.7B and 7C are diagrams 730 and 750, respectively, illustrating additional examples of resource pools for positioning configured within sidelink resource pools for communication. Similar to FIG. 7A, the examples of FIGS. 7B and 7C illustrate shared resource pool structures. With respect to FIGS.7B and 7C, in some designs, the following parameters may be defined, for example: physical sidelink control channel (PSCCH) and 44 QC2403139WOQualcomm Ref. No.2403139WO SL-PRS are only time-division multiplexed, PSSCH and SL-PRS are only time-division multiplexed (e.g., the maximum comb size is 4), PSSCH carries both type 2 sidelink control information (SCI-2) and a sidelink shared channel (SL-SCH) (e.g., a new SCI-2 format is introduced), SL-PRS is mapped on consecutive symbols, SL-PRS is not mapped on symbols with PSSCH demodulation reference signals (DMRS), and / or SL-PRS transmit power is the same as the transmit power of the PSSCH (e.g., this implies per- resource element power boosting will be applied for comb-2 and comb-4).

[0139] FIG.7D is a diagram 770 illustrating another example of a resource pool for positioning configured within a sidelink resource pool for communication. In the example of FIG. 7D, a dedicated resource pool structure is depicted. With respect to FIG. 7D, in some designs, the following parameters may be defined, for example: SL-PRS is immediately preceded by an AGC symbol, SL-PRS is immediately followed by a gap symbol (at least when the gap symbol is the last sidelink symbol in a slot), PSCCH and SL-PRS can only be time-division multiplexed, different comb sizes (N) and SL-PRS durations (M) can be supported in the same resource pool (e.g., one set of SL-PRS resources can only have a single (M, N) combination), PSSCH is mapped to the first sidelink symbols in a slot, the number of PSCCH symbols is (pre-)configured to 1, 2, or 3, the number of physical resource blocks is (pre-)configured using sidelink communications values, and / or there is a one-to-one implicit mapping between PSCCH and SL-PRS.

[0140] In some designs, in a shared resource pool, with regards to the fields in SCI format 2-D, the following fields may be included, for example: a SL-PRS resource information indication of the current slot (ceiling(log2(#SL-PRS resources (pre-)configured in the resource pool) bits)), SL-PRS request (0 or 1 bit), and / or embedded SCI format ([X] bit(s)). If the “embedded SCI format” field is set to [0], the SCI 2-A fields are included with necessary padding. If the “embedded SCI format” field is set to [1], the SCI 2-B fields are included.

[0141] In some designs, for a shared resource pool, there may be an explicit (pre-)configuration of SL-PRS resources in a slot, applicable for an indicated frequency domain allocation, which includes, for example: SL-PRS Resource ID, (M, N) pattern, and / or comb offset. In some designs, for a given value of ‘M,’ a SL-PRS resource is mapped to the last consecutive ‘M’ sidelink symbol(s) in the slot that can be used for SL-PRS, taking into consideration multiplexing with PSSCH DMRS, phase tracking reference signals (PT- QC2403139WOQualcomm Ref. No.2403139WO RS), CSI-RS, PSFCH, gap symbols, AGC symbols, and / or PSCCH in the slot. In some designs, the maximum number of SL-PRS resources in a slot of a shared resource pool may be (pre-)configured.

[0142] In some designs, in dedicated resource pools, with regards to the procedure for determining the subset of resources to be reported to higher layers, when triggering the resource (re-)selection procedure, the higher layers provide the following parameters for candidate SL-PRS transmission(s), for example: resource pool from which to report SL- PRS resources, priority, delay budget, reservation period, list of resources for pre-emption and re-evaluation, and / or the set of SL-PRS resource identifiers that can include all (pre- )configured SL-PRS resource identifiers.

[0143] FIG. 8 illustrates the two resource allocation modes for transmissions on NR sidelinks, according to aspects of the disclosure. In the first mode 810 (labeled “Mode 1”), the base station 802 (e.g., any of the base stations described herein) allocates time and / or frequency resources for sidelink communication between the involved V-UEs 804 and 806 (e.g., any of the V-UEs or sidelink-capable UEs described herein) via DCI 3_0. Each V-UE uses the allocated resources to transmit ranging signals (e.g., SL-PRS) to the other V- UE(s).

[0144] In the second mode 820 (labeled “Mode 2”), the involved UEs 804 and 806 autonomously select sidelink resources to use for transmission of ranging signals. A V-UE can only use the first mode if it has cellular coverage, and can use the second mode regardless of whether or not it has cellular coverage. Note that although FIG. 8 illustrates two V-UEs, as will be appreciated, they need not be V-UEs, and may instead be any other type of UE capable of sidelink communication. In addition, there may be more than the two V-UEs 804 and 806 illustrated.

[0145] Signaling over the sidelink is the same between the two resource allocation modes. From the point of view of the receiver (e.g., V-UE 806), there is no difference between the modes. That is, it does not matter to the receiver whether the resources for the ranging signals were allocated by the base station 802 or the transmitter.

[0146] Mode 1 supports dynamic grant (DG), configured grant (CG) Type 1, and CG Type 2. In some cases, CG Type 1 is activated via RRC signaling from the base station 802. In some cases, the modulation and coding scheme (MCS) for sidelink transmissions is determined by the involved V-UEs 804 and 806 within limits set by the base station 802. In Mode 2, 46 QC2403139WOQualcomm Ref. No.2403139WO the transmitting V-UE (e.g., V-UE 804) performs channel sensing by blindly decodes all physical sidelink control channels (PSCCHs) to determine the resources reserved for other sidelink transmissions. The transmitting V-UE 804 reports available resources to its upper layer and the upper layer determines resource usage.

[0147] In addition, NR sidelinks support hybrid automatic repeat request (HARQ) retransmission. In Mode 1, the base station 802 provides a dynamic grant for HARQ feedback or activates a configured sidelink grant. The sidelink feedback can be reported back to the base station by the transmitting UE (e.g., V-UE 804).

[0148] Positioning is a recent sidelink (SL) feature introduced in some 3GPP standards, achieved via transmission of SL-PRS signals from SL UEs. In some designs, sidelink positioning use cases often involve more than one SL-PRS TX UEs (i.e., UEs that transmit SL-PRS) cooperating as part of the same LCS session (e.g., TDOA positioning technique requires transmission of SL-PRS signals from multiple “anchor” UEs, as depicted in FIG. 5A). Ideally, all the SL-PRS transmissions (TXs) from all the TX UEs in a location services (LCS) session should be performed as close in time as possible to avoid positioning errors due to mobility and / or clock / timing drifts.

[0149] One simple approach to achieve this is that the TX UEs of the session are indicated a (short) time window over which they are independently selecting resources to perform their SL-PRS TXs. The time window duration corresponds to a SL-PRS Delay Budget and is provided to the TX UEs by higher layers. Such aspects may be implemented for Mode-2 resource selection in some designs, i.e., there is no network coverage, and UEs select resources independently. In Mode-2 sidelink positioning, a “server” UE exists that orchestrates the LCS session. However, in some designs, the server UE does not allocate / indicate resources for / to the SL-PRS TX UEs. In addition to multiple SL-PRS TX UEs, an LCS session may require its SL-PRS TX UEs to each transmit more than one SL-PRS signals within the resource selection window (e.g., towards improving positioning accuracy, with the RX (measurement) UE combining the measurements corresponding to SL-PRSs originating from the same TX UE).

[0150] FIG. 9 illustrates a LCS session 900, in accordance with aspects of the disclosure. Note that as used herein, an LCS session is one example of a position estimation session for a target UE. QC2403139WOQualcomm Ref. No.2403139WO

[0151] In FIG. 9, three SL-PRS TX UEs (UEs 1, 2, 3) are participating in the LCS session 900. In FIG.9, assume that each SL-PRS TX UE in the session is required to transmit two SL- PRS signals in respective slots, and all the SL-PRS TXs from all TX UEs must be performed within a time window of at most 7 slots. The SL-PRS TX UEs are indicated a 7-slot a LCS time window for resource selection (via appropriate SL-PRS delay budget) and the SL-PRS TX UEs independently select / reserve their SL-PRS resources within the LCS time window. In an aspect, selection / reservation of SL-PRS resources in some 3GPP standards follows the legacy SL selection / reservation procedures. In an aspect, some 3GPP standards may only allow a single SL-PRS transmission to be performed within a slot by the same UE, however, multiplexing of SL-PRSs originating from different UEs within the same slot is possible in other implementations, e.g., via FDM’ing (“shared” resource pool) or TDM’ing (within slot) plus comb-based multiplexing (“dedicated” resource pool). In FIG. 9, UE 1 transmits SL-PRS in slots 2 and 5, UE 2 transmits SL- PRS in slots 1 and 6, and UE 3 transmits SL-PRS in slots 4 and 7.

[0152] Ideally, SL-PRS TX UEs of an LCS session will (successfully) transmit their required number of SL-PRS signals within the time window, as shown in FIG. 9. However, this may not be possible due to one or more of the following reasons: Reason #1: Transmission of a SL-PRS is performed by a SL-PRS TX UE, but the transmission collides with the transmission by another UE (not necessarily of the same LCS session; not necessarily transmitting SL-PRS), and / or Reason #2: A SL-PRS TX UE may not be able to identify (and select) the required number of SL-PRS resources within the short time window due to resources in the window being reserved by other UEs, and / or Reason #3: A SL-PRS TX UE attempts to transmit over a selected / reserved resource but the transmission is dropped (i.e., not performed) due to a listening before talk (LBT) procedure sensing the channel as busy. This case is only relevant when the resource pool over which SL-PRS transmissions are performed is in an unlicensed / shared band. Some 3GPP standards do not support SL-PRS TXs over shared spectrum, however, SL positioning over shared / unlicensed bands is expected to be introduced in the future.

[0153] Note that Reason #3 applies to both Mode-1 and Mode-2 operation, i.e., even when the network (NW) guarantees a resource allocation that eliminates Reasons #1 and #2. In 48 QC2403139WOQualcomm Ref. No.2403139WO some designs, the NW has no control over other-RAT activity and LBT (performed by the SL-PRS TX UEs when about to transmit) may very well result in blocking transmissions.

[0154] FIG.10 illustrates a LCS session 1000, in accordance with aspects of the disclosure. Note that as used herein, an LCS session is one example of a position estimation session for a target UE.

[0155] In FIG. 10, assume the LCS session 1000 is intended for an implementation that is identical to the LCS session 900 of FIG. 9. So, three SL-PRS TX UEs (UEs 1, 2, 3) are participating in the LCS session 1000, each SL-PRS TX UE in the session is required to transmit two SL-PRS signals in respective slots, all the SL-PRS TXs from all TX UEs must be performed within a time window of at most 7 slots, and so on.

[0156] As in FIG. 9, UE 1 identifies two SL-PRS resources (slots 2 and 5) in the time window. However, the first SL-PRS TX collides with a TX from another UE (UE 4). Note that UE 1 is not aware of the collision (half-duplex operation). Due to the collision, UE 1 effectively performs one SL-PRS TX (at slot 5). Further assume that UE 2 is located in a region with large local activity, with many of the resources appearing unavailable due to reservations by other UEs. Possibly, these reservations occur after UE 2 has (internally) selected a resource, leading UE 2 to re-evaluate / re-select the resource towards the end of the window. In addition, a couple of TX attempts by UE 2 on available resources end up getting blocked by LBT. UE 2 only manages to transmit one SL-PRS TX (e.g., unable to find / select a second available SL-PRS resource within the short window). UE 3 successfully performs two transmissions. In this case, since only four out of the required six SL-PRS transmissions were performed, this session is rendered useless. On top of that, the four SL-PRS transmissions performed effectively contributed only to unnecessary congestion and waste of power.

[0157] In some designs, when one or more of the SL-PRS TX UEs of an LCS session do not manage to perform their required number of SL-PRS TXs (within the session time window), the session is rendered useless (no confidence in positioning accuracy). In addition, any SL-PRS TXs that managed to get transmitted within this useless session effectively only contributed to unnecessary medium congestion and unnecessary power consumption (for the TX UEs that managed to perform SL-PRS TXs). 49 QC2403139WOQualcomm Ref. No.2403139WO

[0158] Aspects of the disclosure are directed to cancellation of a sidelink positioning reference signal (SL-PRS) transmission on one or more SL-PRS resources in a SL-PRS resource pool for a position estimation session, such as a location services (LCS) session. In an aspect, the transmission cancellation of the SL-PRS transmission is based on detection that one or more session cancellation conditions associated with the position estimation session are satisfied. For example, the session cancellation condition(s) may indicate that one or more requirements of the position estimation session cannot be satisfied. Such aspects provide various technical advantages, such as reducing medium congestion and unnecessary power consumption attributable to unnecessary UE transmissions.

[0159] FIG.11 illustrates an exemplary process 1100 of communications according to an aspect of the disclosure. The process 1100 of FIG.11 is performed by a UE, such as UE 302. In an aspect, the UE may correspond to one of a plurality of SL-PRS TX UEs for a position estimation session, such as a LCS session.

[0160] Referring to FIG. 11, at 1110, the UE (e.g., processor(s) 342, SL-PRS component 348, etc.) determines a set of sidelink positioning reference signal (SL-PRS) resources in a SL- PRS resource pool on which to transmit SL-PRS during a time window of a position estimation session. In some designs, a means for performing the determination of 1110 includes processor(s) 342, SL-PRS component 348, etc., of FIG.3A.

[0161] Referring to FIG. 11, at 1120, the UE (e.g., processor(s) 342, SL-PRS component 348, etc.) detects that one or more session cancellation conditions associated with the position estimation session are satisfied. In some designs, a means for performing the detection of 1120 includes processor(s) 342, SL-PRS component 348, etc., of FIG.3A.

[0162] Referring to FIG. 11, at 1130, the UE (e.g., processor(s) 342, SL-PRS component 348, etc.) cancels transmission of the SL-PRS on one or more SL-PRS resources of the set of SL-PRS resources based on the detection of the one or more session cancellation conditions and irrespective of an availability of the one or more SL-PRS resources. In some designs, a means for performing the cancellation of 1130 includes processor(s) 342, SL-PRS component 348, etc., of FIG.3A.

[0163] Referring to FIG.11, in some designs, the canceling comprises canceling the transmission of the SL-PRS on each SL-PRS resource of the set of SL-PRS resources that is subsequent to a time of the detection of the one or more session cancellation conditions. In other words, to cancel transmission of the SL-PRS, one or more processors are configured to 50 QC2403139WOQualcomm Ref. No.2403139WO cancel the transmission of the SL-PRS on each SL-PRS resource of the set of SL-PRS resources that is subsequent to a time of the detection of the one or more session cancellation conditions.

[0164] Referring to FIG. 11, in some designs, before the detection of the one or more session cancellation conditions, the UE performs at least one transmission of the SL-PRS on at least one SL-PRS resource of the set of SL-PRS resources. In other designs, the canceling comprises canceling the transmission of the SL-PRS on each SL-PRS resource of the set of SL-PRS resources (i.e., in this case, no SL-PRS transmission by the UE occurs prior to the detection at 1120). In other words, to cancel transmission of the SL-PRS, one or more processors are configured to cancel the transmission of the SL-PRS on each SL- PRS resource of the set of SL-PRS resources.

[0165] Referring to FIG.11, in some designs, the position estimation session is associated with a plurality of UEs attempting to perform SL-PRS transmissions via the SL-PRS resource pool during the time window, and the plurality of UEs comprises the UE.

[0166] Referring to FIG. 11, in some designs, the one or more session cancellation conditions are indicative of failure for at least one requirement associated with the position estimation session.

[0167] Referring to FIG. 11, in some designs, the one or more session cancellation conditions are evaluated prior to each attempt to perform any transmission of the SL-PRS by the UE on any of the set of SL-PRS resources.

[0168] Referring to FIG. 11, in some designs, the one or more session cancellation conditions are configured or pre-configured or activated or deactivated based on a configuration of the SL-PRS resource pool, or the one or more session cancellation conditions are configured or pre-configured or activated or deactivated via radio resource control (RRC) signaling, or the one or more session cancellation conditions are configured or pre- configured or activated or deactivated via higher-layer sidelink signaling (e.g., sidelink positioning protocol (SLPP)).

[0169] Referring to FIG. 11, in some designs, the detecting at 1120 evaluates the one or more session cancellation conditions with respect to a given time during the time window of the position estimation session. In an aspect, the one or more session cancellation conditions comprise, e.g.: 51 QC2403139WOQualcomm Ref. No.2403139WO a total count of SL-PRS transmissions performed during the position estimation session up until the given time by any UE associated with the position estimation session being below a first threshold, or a number of UEs associated with the position estimation session that have performed at least a first number of SL-PRS transmissions during the position estimation session up until the given time being below a second threshold, or a total number of listen before talk (LBT) failures by the UE during the position estimation session up until the given time being above a third threshold, or a number of remaining SL-PRS resources in the SL-PRS resource pool within the time window subsequent to the given time being insufficient for at least one UE participating in the position estimation session to perform a threshold total number of SL-PRS transmissions during the position estimation session, or a number of session cancellation notifications received during the position estimation session up until the given time from one or more other UEs participating in the position estimation session being above or below a fourth threshold, or any combination thereof.

[0170] Referring to FIG. 11, in some designs, the one or more session cancellation conditions comprise at least one session criterion that is compared against a fixed threshold.

[0171] Referring to FIG. 11, in some designs, the one or more session cancellation conditions comprise at least one session criterion that is compared against a dynamic threshold. In an aspect, the dynamic threshold is based on a set of criteria comprising, e.g.: an amount of time from a startpoint of the time window to the given time, or an amount of time from the given time to an endpoint of the time window, or a total number of UEs associated with the position estimation session attempting to perform SL-PRS transmissions during the position estimation session, or a minimum number of UEs associated with the position estimation session required to perform successful SL-PRS transmissions during the position estimation session, or a minimum number of SL-PRS transmissions to be performed per UE associated with the position estimation session that attempts to transmit SL-PRS during the position estimation session, or any combination thereof. QC2403139WOQualcomm Ref. No.2403139WO

[0172] Referring to FIG. 11, in some designs, the set of criteria is indicated based on a configuration of the SL-PRS resource pool, or the set of criteria is indicated via radio resource control (RRC) signaling, or the set of criteria is indicated via higher-layer sidelink signaling (e.g., SLPP).

[0173] Referring to FIG. 11, in some designs, the detection at 1120 includes identifying a SL- PRS transmission from another UE on the SL-PRS resource pool during the position estimation session as being associated with the position estimation session. In an aspect, the identifying is based on a sidelink communication information (SCI) associated with the SL-PRS transmission from the another UE. In an aspect, the identifying is based on a source identifier field of the SCI, or the identifying is based on a destination identifier field of the SCI, or the identifying is based on a session identifier field of the SCI, or any combination thereof. In an aspect, the identifying is based on reference signal received power (RSRP) measurement associated with the SL-PRS transmission from the another UE.

[0174] Referring to FIG. 11, in some designs, the UE further transmits a session cancellation notification that indicates that the UE is canceling participation in the position estimation session, e.g.: the session cancellation notification is unicast or groupcast, or the session cancellation notification comprises a session identifier associated with the position estimation session, or the session cancellation notification comprises a first number of the one or more SL- PRS resources for which the transmission of the SL-PRS is canceled by the UE, or the session cancellation notification comprises a second number SL-PRS transmissions performed by the UE during the position estimation session prior to the transmission of the session cancellation notification, or the session cancellation notification comprises an indication of the one or more session cancellation conditions, or any combination thereof.

[0175] Referring to FIG. 11, in some designs, the position estimation session corresponds to a location services (LCS) session.

[0176] Referring to FIG. 11, a specific example, the SL-PRS TX UEs of an LCS session may perform their respective SL-PRS transmissions independently. In an aspect, a SL-PRS QC2403139WOQualcomm Ref. No.2403139WO TX UE may proceed with transmitting its own SL-PRS(s), irrespective of the status of the TXs by other TX UEs in the session (e.g., even if all other SL-PRS transmissions from all other SL-PRS TX UEs in the session fail). Since the “success” of a SL-PRS TX in the content of a multi-TX-UE LCS session not only depends on the success of the SL-PRS transmission itself but also on the success of the other SL-PRS transmissions in that same session, a SL-PRS TX UE may monitor the activity of the other SL-PRS TXs in the session before deciding whether to proceed or not with its own transmission. For example, a SL-PRS TX UE that (1) has a pending SL-PRS transmission and (2) is aware that the other SL-PRS TX UE(s) in the session will not manage to perform their required transmission(s) within the time window, will drop the pending transmission as it will be a useless transmission. By doing this, unnecessary medium congestion and power consumption is reduced or avoided. In an aspect, a new condition for resource re- evaluation trigger may be introduced. In an aspect, this condition is in addition to the legacy re-evaluation trigger due to observing a selected resource no longer available due to someone else reserving it. However, in an aspect, this re-evaluation condition results in dropping the TX (as well as any other pending TX after it) and not re-selecting resources for another SL-PRS transmission attempt.

[0177] FIG. 12 illustrates an example implementation 1200 of the process 1100 of FIG. 11, in accordance with aspects of the disclosure. In particular, FIG.12 depicts a LCS session.

[0178] In FIG.12, three SL-PRS TX UEs (UEs 1, 2, 3) are participating in the LCS session 1200. In FIG. 12, assume that each SL-PRS TX UE in the session is required to transmit two SL-PRS signals in respective slots, and all the SL-PRS TXs from all TX UEs must be performed within a time window of at most 7 slots. The SL-PRS TX UEs are indicated a 7-slot a LCS time window for resource selection (via appropriate SL-PRS delay budget) and the SL-PRS TX UEs independently select / reserve their SL-PRS resources within the LCS time window. In an aspect, selection / reservation of SL-PRS resources in some 3GPP standards follows the legacy SL selection / reservation procedures. In an aspect, some 3GPP standards may only allow a single SL-PRS transmission to be performed within a slot by the same UE, however, multiplexing of SL-PRSs originating from different UEs within the same slot is possible in other implementations, e.g., via FDM’ing (“shared” resource pool) or TDM’ing (within slot) plus comb-based multiplexing (“dedicated” resource pool). In FIG. 9, UE 1 selects slots 2 and 5 for SL-PRS transmission, UE 2 54 QC2403139WOQualcomm Ref. No.2403139WO selects 1 and 4 for SL-PRS transmission, and UE 3 selects slots 3 and 7 for SL-PRS transmission.

[0179] Referring to FIG. 12, the SL-PRS transmissions by UE 1 at slots 2 and 5 collide with transmissions from another UE (UE 4). At some point before slot 7 (e.g., during slot 6), UE 3 observes that UE 1 has not managed to successfully perform any SL-PRS transmission, such that the SL-PRS transmission requirement for the LCS session cannot be achieved. UE 3 thereby realizes that UE 1 cannot possibly manage to perform its two SL-PRS transmissions within the time window, since only 1 slot is left in the window. Note that in some designs (according to some 3GPP standards procedures) a UE can only transmit a single SL-PRS within a slot. UE 3 cancels (drops) its pending second SL-PRS TX (originally scheduled to occur at slot #7) as it is aware the LCS session has failed and there is no point in performing this transmission.

[0180] Referring to FIG.11, a specific example, a SL-PRS TX UE, that is part of an LCS session comprised of multiple SL-PRS TX UEs may drop (i.e., not perform at all) a pending SL- PRS transmission (and any following pending SL-PRS transmissions) within the session time window when one or more conditions are satisfied. In an aspect, these conditions reflect the ability of the other SL-PRS TX UEs in the session (including the TX UE performing the condition evaluation) actually being able to fulfill the required SL-PRS transmission within the session time window. In an aspect, the condition(s) are evaluated at a (pre-)configured time T prior the start of each pending SL-PRS transmission (e.g., the time T3 used for re-evaluation / pre-emption check (already defined in some 3GPP specifications) may be re-used or a new timer could be defined.

[0181] Referring to FIG.11, a specific example, a SL-PRS TX UE may evaluate (or not evaluate) the condition(s) in response to a trigger, which may be indicated via (pre-)configuration of the SL-PRS resource pool, or via RRC configuration, or via higher layer (e.g., SLPP) signaling (e.g., part of AssistanceData message).

[0182] Referring to FIG.11, a specific example, the condition(s) that indicate (or trigger) session cancellation may include, e.g.: The total number of performed SL-PRS TXs as part of the LCS session (by any UE, including the one performing the condition evaluation) from the start of the session (time window) till the time of evaluation is below / above a threshold number, or QC2403139WOQualcomm Ref. No.2403139WO The number of SL-PRS TX UEs in the session having performed at least X transmissions from the start of the session (time window) till the time of evaluation is below / above a threshold number, or The number of LBT failures the TX UE performing the evaluation has experienced from the start of the session (time window) till the time of evaluation is below / above a threshold number (e.g., a large number of LBT failures may suggest heavy interference that is most likely also experienced by other TX UEs, hence lower likelihood for any UE to be able to perform the TXs on time), or The number of remaining selected resources in the time window by the TX UE at the time of evaluation is not sufficient for the number of TXs the UE has left to perform prior the end of the time window (e.g., a TX has another 2 SL-PRS TXs to perform but can only identify 1 SL-PRS resource within the time window, will drop that TX), or The number of other SL-PRS TX UEs having declared “RLF” (radio link failure, which may alternatively be referred to herein as session cancellation) from the start of the session (time window) till the time of evaluation is below / above a threshold number (e.g., assuming that SL-PRS TX UEs signal RLF when they abort their pending SL-PRS TXs within the time window (discussed below in more detail), or Any combination thereof.

[0183] Referring to FIG.11, a specific example, the condition(s) that indicate (or trigger) session cancellation may be indicated via higher-layer signaling (e.g., SLPP message), SL-PRS resource pool RRC (pre-)configuration, or a combination thereof.

[0184] Referring to FIG.11, a specific example, the threshold numbers and value of X discussed with respect to the above-noted condition(s) may be different from each other. In an aspect, the threshold numbers and value of X may be (pre-)configured fixed values. In another aspect, the threshold numbers and value of X may be left up to UE implementation (i.e., not defined in 3GPP standard). In another aspect, the threshold numbers and value of X may be non-fixed (or dynamic) values that depend on one or more of the following parameters, e.g.; Time passed (e.g., # of slots) since the start of the session time window, or Time remaining (e.g., # of slots) since the end to the session time window, or 56 QC2403139WOQualcomm Ref. No.2403139WO Total # of SL-PRS TX UEs participating in the session (and expected to transmit within the time window), or Minimum # of SL-PRS TX UEs that must (successfully) transmit in the session (e.g., a session may include 10 SL-PRS TX UEs, but it is not necessary that all of them transmit to achieve positioning), or [minimum] # of SL-PRS TXs each SL-PRS TX UE participating in the session must perform (within the time window), or The last 3 parameters above are indicated to each TX UE via higher layers (SLPP) when the session is established (e.g., part of assistanceData message), or Any combination thereof.

[0185] Referring to FIG. 11, a specific example, a SL-PRS TX UE 1 observing a SL-PRS transmission may identify that transmission as originating from a SL-PRS TX UE 2 in the same LCS session. This identification may then be applied to the evaluation of the above-noted condition(s).

[0186] Referring to FIG.11, a specific example, a SL-PRS TX UE 1 of an LCS session, considers a SL-PRS transmission by another SL-PRS TX UE2 of the same session as (successfully) performed when one or more of the following conditions are satisfied, e.g.: TX UE 1 decoded SCI of the SL-PRS transmission by TX UE 2 (note: examples of how to determine that an SCI corresponds to a SL-PRS TX of the same session is addressed below in more detail), and / or RSRP of SL-PRS transmission by TX UE2 is above a threshold (e.g., RSRP can be measured over PSCCH (associated with the SL-PRS), or SL-PRS, or both; note that this condition may be evaluated in addition to the decoding of the SCI (e.g., SCI may be decoded first in order to identify the transmission originates from another TX UE in the same session).

[0187] Referring to FIG.11, a specific example, one simple way to associate a decoded SCI with an LCS session is based on the source and destination IDs that are already provided in the SCI of the PSCCH associated with a SL-PRS. However, coordination may be needed so that these IDs are known among TX UEs of the same LCS session.

[0188] Referring to FIG. 11, a specific example, the source ID (appearing in the SCI) used by each SL-PRS TX UE in an LCS session is known by all the other SL-PRS TX UEs in the session. In an aspect, this information is provided via SLPP (“AssistanceData” message). QC2403139WOQualcomm Ref. No.2403139WO In an aspect, this information implicitly provides the total number of TX UEs participating in the session. In another aspect, the destination ID used by each SL-PRS TX UE in an LCS session may be common to all SL-PRS TX UEs or known to all other SL-PRS TX UEs. In an aspect, this information is provided via SLPP (“AssistanceData” message).

[0189] Referring to FIG.11, a specific example, to resolve ambiguities of source / destination ID (due to only a truncated version appearing in the SCI), the session ID may also be indicated in the SCI. In an aspect, the SCI of the PSCCH associated with a SL-PRS transmission indicates the session ID the SL-PRS TX belongs to.

[0190] Referring to FIG. 11, a specific example, and based on the above, SL-PRS TX UE of anLCS session identifies that a transmission originates from another SL-PRS TX UE of the same session based on the Source ID, Destination ID and / or Session ID associated with the other SL-PRS TX UE as communicated via the SCI.

[0191] Referring to FIG. 11, a specific example, it may be beneficial for a SL-PRS TX UE to signal that it abandons its remaining SL-PRS TXs. For example, such a communication (referred to above as a session cancellation notification) may be useful to assist other SL- PRS TX UEs in the session to potentially decide the same and / or to make the server UE (or LMF) aware of the event as soon as possible (and take corresponding action as soon as possible). To this end, when a SL-PRS TX UE aborts its pending SL-PRS transmission(s) within the remaining time window of an LCS session without having performed the minimum number of SL-PRS transmissions for that session, the SL-PRS TX UE may transmitter transmits an “RLF” indication (or session cancellation notification). In an aspect, the “RLF” may be transmitted via Groupcast (e.g., with destination group the SL-PRS TX UEs and server UE of the LCS session), or Unicast (e.g., towards the server UE alone). In an aspect, the “RLF” indication may indicate session ID of the LCS session. In an aspect, the “RLF” indication may indicate a number of SL-PRS TXs dropped by the SL-PRS TX UE and / or a number of SL-PRS TXs performed (within the session) by the SL-PRS TX UE prior to RLF trigger. In an aspect, the “RLF” indication may indicate condition(s) that triggered RLF (e.g., any of the condition(s) described above).

[0192] In the detailed description above it can be seen that different features are grouped together in examples. This manner of disclosure should not be understood as an intention that the 58 QC2403139WOQualcomm Ref. No.2403139WO example clauses have more features than are explicitly mentioned in each clause. Rather, the various aspects of the disclosure may include fewer than all features of an individual example clause disclosed. Therefore, the following clauses should hereby be deemed to be incorporated in the description, wherein each clause by itself can stand as a separate example. Although each dependent clause can refer in the clauses to a specific combination with one of the other clauses, the aspect(s) of that dependent clause are not limited to the specific combination. It will be appreciated that other example clauses can also include a combination of the dependent clause aspect(s) with the subject matter of any other dependent clause or independent clause or a combination of any feature with other dependent and independent clauses. The various aspects disclosed herein expressly include these combinations, unless it is explicitly expressed or can be readily inferred that a specific combination is not intended (e.g., contradictory aspects, such as defining an element as both an electrical insulator and an electrical conductor). Furthermore, it is also intended that aspects of a clause can be included in any other independent clause, even if the clause is not directly dependent on the independent clause.

[0193] Implementation examples are described in the following numbered clauses:

[0194] Clause 1. A method performed by a user equipment (UE), comprising: determining a set of sidelink positioning reference signal (SL-PRS) resources in a SL-PRS resource pool on which to transmit SL-PRS during a time window of a position estimation session; detecting that one or more session cancellation conditions associated with the position estimation session are satisfied; and canceling transmission of the SL-PRS on one or more SL-PRS resources of the set of SL-PRS resources based on the detection of the one or more session cancellation conditions and irrespective of an availability of the one or more SL-PRS resources.

[0195] Clause 2. The method of clause 1, wherein, to cancel transmission of the SL-PRS, the one or more processors are configured to cancel the transmission of the SL-PRS on each SL- PRS resource of the set of SL-PRS resources that is subsequent to a time of the detection of the one or more session cancellation conditions.

[0196] Clause 3. The method of any of clauses 1 to 2, further comprising: performing, before the detection of the one or more session cancellation conditions, at least one transmission of the SL-PRS on at least one SL-PRS resource of the set of SL-PRS resources. 59 QC2403139WOQualcomm Ref. No.2403139WO

[0197] Clause 4. The method of any of clauses 1 to 3, wherein the canceling comprises canceling the transmission of the SL-PRS on each SL-PRS resource of the set of SL-PRS resources.

[0198] Clause 5. The method of any of clauses 1 to 4, wherein the position estimation session is associated with a plurality of UEs attempting to perform SL-PRS transmissions via the SL-PRS resource pool during the time window, and wherein the plurality of UEs comprises the UE.

[0199] Clause 6. The method of any of clauses 1 to 5, wherein the one or more session cancellation conditions are indicative of failure for at least one requirement associated with the position estimation session.

[0200] Clause 7. The method of any of clauses 1 to 6, wherein the one or more session cancellation conditions are evaluated prior to each attempt to perform any transmission of the SL-PRS by the UE on any of the set of SL-PRS resources.

[0201] Clause 8. The method of any of clauses 1 to 7, wherein the one or more session cancellation conditions are configured or pre-configured or activated or deactivated based on a configuration of the SL-PRS resource pool, or wherein the one or more session cancellation conditions are configured or pre-configured or activated or deactivated via radio resource control (RRC) signaling, or wherein the one or more session cancellation conditions are configured or pre-configured or activated or deactivated via higher-layer sidelink signaling.

[0202] Clause 9. The method of any of clauses 1 to 8, wherein the detecting evaluates the one or more session cancellation conditions with respect to a given time during the time window of the position estimation session.

[0203] Clause 10. The method of clause 9, wherein the one or more session cancellation conditions comprise: a total count of SL-PRS transmissions performed during the position estimation session up until the given time by any UE associated with the position estimation session being below a first threshold, or a number of UEs associated with the position estimation session that have performed at least a first number of SL-PRS transmissions during the position estimation session up until the given time being below a second threshold, or a total number of listen before talk (LBT) failures by the UE during the position estimation session up until the given time being above a third threshold, or a number of remaining SL-PRS resources in the SL-PRS resource pool within the time window subsequent to the given time being insufficient for at least one UE participating 60 QC2403139WOQualcomm Ref. No.2403139WO in the position estimation session to perform a threshold total number of SL-PRS transmissions during the position estimation session, or a number of session cancellation notifications received during the position estimation session up until the given time from one or more other UEs participating in the position estimation session being above or below a fourth threshold, or any combination thereof.

[0204] Clause 11. The method of any of clauses 9 to 10, wherein the one or more session cancellation conditions comprise at least one session criterion that is compared against a fixed threshold.

[0205] Clause 12. The method of any of clauses 9 to 11, wherein the one or more session cancellation conditions comprise at least one session criterion that is compared against a dynamic threshold.

[0206] Clause 13. The method of clause 12, wherein the dynamic threshold is based on a set of criteria comprising: an amount of time from a startpoint of the time window to the given time, or an amount of time from the given time to an endpoint of the time window, or a total number of UEs associated with the position estimation session attempting to perform SL-PRS transmissions during the position estimation session, or a minimum number of UEs associated with the position estimation session required to perform successful SL- PRS transmissions during the position estimation session, or a minimum number of SL- PRS transmissions to be performed per UE associated with the position estimation session that attempts to transmit SL-PRS during the position estimation session, or any combination thereof.

[0207] Clause 14. The method of clause 13, wherein the set of criteria is indicated based on a configuration of the SL-PRS resource pool, or wherein the set of criteria is indicated via radio resource control (RRC) signaling, or wherein the set of criteria is indicated via higher-layer sidelink signaling.

[0208] Clause 15. The method of any of clauses 1 to 14, wherein detecting comprises: identifying a SL-PRS transmission from another UE on the SL-PRS resource pool during the position estimation session as being associated with the position estimation session.

[0209] Clause 16. The method of clause 15, wherein the one or more processors are configured to identify the SL-PRS transmission from the another UE based on a sidelink communication information (SCI) associated with the SL-PRS transmission from the another UE. 61 QC2403139WOQualcomm Ref. No.2403139WO

[0210] Clause 17. The method of clause 16, wherein the one or more processors are configured to identify the SL-PRS transmission from the another UE based on a source identifier field of the SCI, or wherein the identifying is based on a destination identifier field of the SCI, or wherein the identifying is based on a session identifier field of the SCI, or any combination thereof.

[0211] Clause 18. The method of any of clauses 15 to 17, wherein the one or more processors are configured to identify the SL-PRS transmission from the another UE based on reference signal received power (RSRP) measurement associated with the SL-PRS transmission from the another UE.

[0212] Clause 19. The method of any of clauses 1 to 18, further comprising: transmitting a session cancellation notification that indicates that the UE is canceling participation in the position estimation session.

[0213] Clause 20. The method of clause 19, wherein the session cancellation notification is unicast or groupcast, or wherein the session cancellation notification comprises a session identifier associated with the position estimation session, or wherein the session cancellation notification comprises a first number of the one or more SL-PRS resources for which the transmission of the SL-PRS is canceled by the UE, or wherein the session cancellation notification comprises a second number SL-PRS transmissions performed by the UE during the position estimation session prior to the transmission of the session cancellation notification, or wherein the session cancellation notification comprises an indication of the one or more session cancellation conditions, or any combination thereof.

[0214] Clause 21. The method of any of clauses 1 to 20, wherein the position estimation session corresponds to a location services (LCS) session.

[0215] Clause 22. A user equipment (UE), comprising: one or more memories; one or more transceivers; and one or more processors communicatively coupled to the one or more memories and the one or more transceivers, the one or more processors, either alone or in combination, configured to: determine a set of sidelink positioning reference signal (SL- PRS) resources in a SL-PRS resource pool on which to transmit SL-PRS during a time window of a position estimation session; detect that one or more session cancellation conditions associated with the position estimation session are satisfied; and cancel transmission of the SL-PRS on one or more SL-PRS resources of the set of SL-PRS QC2403139WOQualcomm Ref. No.2403139WO resources based on the detection of the one or more session cancellation conditions and irrespective of an availability of the one or more SL-PRS resources.

[0216] Clause 23. The UE of clause 22, wherein, to cancel transmission of the SL-PRS, the one or more processors are configured to cancel the transmission of the SL-PRS on each SL- PRS resource of the set of SL-PRS resources that is subsequent to a time of the detection of the one or more session cancellation conditions.

[0217] Clause 24. The UE of any of clauses 22 to 23, wherein the one or more processors, either alone or in combination, are further configured to: perform, before the detection of the one or more session cancellation conditions, at least one transmission of the SL-PRS on at least one SL-PRS resource of the set of SL-PRS resources.

[0218] Clause 25. The UE of any of clauses 22 to 24, wherein, to cancel transmission of the SL- PRS, the one or more processors are configured to cancel the transmission of the SL-PRS on each SL-PRS resource of the set of SL-PRS resources.

[0219] Clause 26. The UE of any of clauses 22 to 25, wherein the position estimation session is associated with a plurality of UEs attempting to perform SL-PRS transmissions via the SL-PRS resource pool during the time window, and wherein the plurality of UEs comprises the UE.

[0220] Clause 27. The UE of any of clauses 22 to 26, wherein the one or more session cancellation conditions are indicative of failure for at least one requirement associated with the position estimation session.

[0221] Clause 28. The UE of any of clauses 22 to 27, wherein the one or more session cancellation conditions are evaluated prior to each attempt to perform any transmission of the SL-PRS by the UE on any of the set of SL-PRS resources.

[0222] Clause 29. The UE of any of clauses 22 to 28, wherein the one or more session cancellation conditions are configured or pre-configured or activated or deactivated based on a configuration of the SL-PRS resource pool, or wherein the one or more session cancellation conditions are configured or pre-configured or activated or deactivated via radio resource control (RRC) signaling, or wherein the one or more session cancellation conditions are configured or pre-configured or activated or deactivated via higher-layer sidelink signaling.

[0223] Clause 30. The UE of any of clauses 22 to 29, wherein, to detect that one or more session cancellation conditions are satisfied, the one or more processors are configured to QC2403139WOQualcomm Ref. No.2403139WO evaluate the one or more session cancellation conditions with respect to a given time during the time window of the position estimation session.

[0224] Clause 31. The UE of clause 30, wherein the one or more session cancellation conditions comprise: a total count of SL-PRS transmissions performed during the position estimation session up until the given time by any UE associated with the position estimation session being below a first threshold, or a number of UEs associated with the position estimation session that have performed at least a first number of SL-PRS transmissions during the position estimation session up until the given time being below a second threshold, or a total number of listen before talk (LBT) failures by the UE during the position estimation session up until the given time being above a third threshold, or a number of remaining SL-PRS resources in the SL-PRS resource pool within the time window subsequent to the given time being insufficient for at least one UE participating in the position estimation session to perform a threshold total number of SL-PRS transmissions during the position estimation session, or a number of session cancellation notifications received during the position estimation session up until the given time from one or more other UEs participating in the position estimation session being above or below a fourth threshold, or any combination thereof.

[0225] Clause 32. The UE of any of clauses 30 to 31, wherein the one or more session cancellation conditions comprise at least one session criterion that is compared against a fixed threshold.

[0226] Clause 33. The UE of any of clauses 30 to 32, wherein the one or more session cancellation conditions comprise at least one session criterion that is compared against a dynamic threshold.

[0227] Clause 34. The UE of clause 33, wherein the dynamic threshold is based on a set of criteria comprising: an amount of time from a startpoint of the time window to the given time, or an amount of time from the given time to an endpoint of the time window, or a total number of UEs associated with the position estimation session attempting to perform SL- PRS transmissions during the position estimation session, or a minimum number of UEs associated with the position estimation session required to perform successful SL-PRS transmissions during the position estimation session, or a minimum number of SL-PRS transmissions to be performed per UE associated with the position estimation session that 64 QC2403139WOQualcomm Ref. No.2403139WO attempts to transmit SL-PRS during the position estimation session, or any combination thereof.

[0228] Clause 35. The UE of clause 34, wherein the set of criteria is indicated based on a configuration of the SL-PRS resource pool, or wherein the set of criteria is indicated via radio resource control (RRC) signaling, or wherein the set of criteria is indicated via higher-layer sidelink signaling.

[0229] Clause 36. The UE of any of clauses 22 to 35, wherein, to detect, the one or more processors, either alone or in combination, are configured to: identify a SL-PRS transmission from another UE on the SL-PRS resource pool during the position estimation session as being associated with the position estimation session.

[0230] Clause 37. The UE of clause 36, wherein the identifying is based on a sidelink communication information (SCI) associated with the SL-PRS transmission from the another UE.

[0231] Clause 38. The UE of clause 37, wherein the identifying is based on a source identifier field of the SCI, or wherein the identifying is based on a destination identifier field of the SCI, or wherein the identifying is based on a session identifier field of the SCI, or any combination thereof.

[0232] Clause 39. The UE of any of clauses 36 to 38, wherein the identifying is based on reference signal received power (RSRP) measurement associated with the SL-PRS transmission from the another UE.

[0233] Clause 40. The UE of any of clauses 22 to 39, wherein the one or more processors, either alone or in combination, are further configured to: transmit, via the one or more transceivers, a session cancellation notification that indicates that the UE is canceling participation in the position estimation session.

[0234] Clause 41. The UE of clause 40, wherein the session cancellation notification is unicast or groupcast, or wherein the session cancellation notification comprises a session identifier associated with the position estimation session, or wherein the session cancellation notification comprises a first number of the one or more SL-PRS resources for which the transmission of the SL-PRS is canceled by the UE, or wherein the session cancellation notification comprises a second number SL-PRS transmissions performed by the UE during the position estimation session prior to the transmission of the session QC2403139WOQualcomm Ref. No.2403139WO cancellation notification, or wherein the session cancellation notification comprises an indication of the one or more session cancellation conditions, or any combination thereof.

[0235] Clause 42. The UE of any of clauses 22 to 41, wherein the position estimation session corresponds to a location services (LCS) session.

[0236] Clause 43. A user equipment (UE), comprising: means for determining a set of sidelink positioning reference signal (SL-PRS) resources in a SL-PRS resource pool on which to transmit SL-PRS during a time window of a position estimation session; means for detecting that one or more session cancellation conditions associated with the position estimation session are satisfied; and means for canceling transmission of the SL-PRS on one or more SL-PRS resources of the set of SL-PRS resources based on the detection of the one or more session cancellation conditions and irrespective of an availability of the one or more SL-PRS resources.

[0237] Clause 44. The UE of clause 43, wherein, to cancel transmission of the SL-PRS, the means for canceling cancels the transmission of the SL-PRS on each SL-PRS resource of the set of SL-PRS resources that is subsequent to a time of the detection of the one or more session cancellation conditions.

[0238] Clause 45. The UE of any of clauses 43 to 44, further comprising: means for performing, before the detection of the one or more session cancellation conditions, at least one transmission of the SL-PRS on at least one SL-PRS resource of the set of SL-PRS resources.

[0239] Clause 46. The UE of any of clauses 43 to 45, wherein, to cancel transmission of the SL- PRS, the means for canceling cancels the transmission of the SL-PRS on each SL-PRS resource of the set of SL-PRS resources.

[0240] Clause 47. The UE of any of clauses 43 to 46, wherein the position estimation session is associated with a plurality of UEs attempting to perform SL-PRS transmissions via the SL-PRS resource pool during the time window, and wherein the plurality of UEs comprises the UE.

[0241] Clause 48. The UE of any of clauses 43 to 47, wherein the one or more session cancellation conditions are indicative of failure for at least one requirement associated with the position estimation session. 66 QC2403139WOQualcomm Ref. No.2403139WO

[0242] Clause 49. The UE of any of clauses 43 to 48, wherein the one or more session cancellation conditions are evaluated prior to each attempt to perform any transmission of the SL-PRS by the UE on any of the set of SL-PRS resources.

[0243] Clause 50. The UE of any of clauses 43 to 49, wherein the one or more session cancellation conditions are configured or pre-configured or activated or deactivated based on a configuration of the SL-PRS resource pool, or wherein the one or more session cancellation conditions are configured or pre-configured or activated or deactivated via radio resource control (RRC) signaling, or wherein the one or more session cancellation conditions are configured or pre-configured or activated or deactivated via higher-layer sidelink signaling.

[0244] Clause 51. The UE of any of clauses 43 to 50, wherein, to detect that one or more session cancellation conditions are satisfied, the means for detecting are configured to evaluate the one or more session cancellation conditions with respect to a given time during the time window of the position estimation session.

[0245] Clause 52. The UE of clause 51, wherein the one or more session cancellation conditions comprise: a total count of SL-PRS transmissions performed during the position estimation session up until the given time by any UE associated with the position estimation session being below a first threshold, or a number of UEs associated with the position estimation session that have performed at least a first number of SL-PRS transmissions during the position estimation session up until the given time being below a second threshold, or a total number of listen before talk (LBT) failures by the UE during the position estimation session up until the given time being above a third threshold, or a number of remaining SL-PRS resources in the SL-PRS resource pool within the time window subsequent to the given time being insufficient for at least one UE participating in the position estimation session to perform a threshold total number of SL-PRS transmissions during the position estimation session, or a number of session cancellation notifications received during the position estimation session up until the given time from one or more other UEs participating in the position estimation session being above or below a fourth threshold, or any combination thereof.

[0246] Clause 53. The UE of any of clauses 51 to 52, wherein the one or more session cancellation conditions comprise at least one session criterion that is compared against a fixed threshold. QC2403139WOQualcomm Ref. No.2403139WO

[0247] Clause 54. The UE of any of clauses 51 to 53, wherein the one or more session cancellation conditions comprise at least one session criterion that is compared against a dynamic threshold.

[0248] Clause 55. The UE of clause 54, wherein the dynamic threshold is based on a set of criteria comprising: an amount of time from a startpoint of the time window to the given time, or an amount of time from the given time to an endpoint of the time window, or a total number of UEs associated with the position estimation session attempting to perform SL- PRS transmissions during the position estimation session, or a minimum number of UEs associated with the position estimation session required to perform successful SL-PRS transmissions during the position estimation session, or a minimum number of SL-PRS transmissions to be performed per UE associated with the position estimation session that attempts to transmit SL-PRS during the position estimation session, or any combination thereof.

[0249] Clause 56. The UE of clause 55, wherein the set of criteria is indicated based on a configuration of the SL-PRS resource pool, or wherein the set of criteria is indicated via radio resource control (RRC) signaling, or wherein the set of criteria is indicated via higher-layer sidelink signaling.

[0250] Clause 57. The UE of any of clauses 43 to 56, wherein the means for detecting comprises: means for identifying a SL-PRS transmission from another UE on the SL-PRS resource pool during the position estimation session as being associated with the position estimation session.

[0251] Clause 58. The UE of clause 57, wherein the identifying is based on a sidelink communication information (SCI) associated with the SL-PRS transmission from the another UE.

[0252] Clause 59. The UE of clause 58, wherein the identifying is based on a source identifier field of the SCI, or wherein the identifying is based on a destination identifier field of the SCI, or wherein the identifying is based on a session identifier field of the SCI, or any combination thereof.

[0253] Clause 60. The UE of any of clauses 57 to 59, wherein the identifying is based on reference signal received power (RSRP) measurement associated with the SL-PRS transmission from the another UE. 68 QC2403139WOQualcomm Ref. No.2403139WO

[0254] Clause 61. The UE of any of clauses 43 to 60, further comprising: means for transmitting a session cancellation notification that indicates that the UE is canceling participation in the position estimation session.

[0255] Clause 62. The UE of clause 61, wherein the session cancellation notification is unicast or groupcast, or wherein the session cancellation notification comprises a session identifier associated with the position estimation session, or wherein the session cancellation notification comprises a first number of the one or more SL-PRS resources for which the transmission of the SL-PRS is canceled by the UE, or wherein the session cancellation notification comprises a second number SL-PRS transmissions performed by the UE during the position estimation session prior to the transmission of the session cancellation notification, or wherein the session cancellation notification comprises an indication of the one or more session cancellation conditions, or any combination thereof.

[0256] Clause 63. The UE of any of clauses 43 to 62, wherein the position estimation session corresponds to a location services (LCS) session.

[0257] Clause 64. A non-transitory computer-readable medium storing computer-executable instructions that, when executed by a user equipment (UE), cause the UE to: determine a set of sidelink positioning reference signal (SL-PRS) resources in a SL-PRS resource pool on which to transmit SL-PRS during a time window of a position estimation session; detect that one or more session cancellation conditions associated with the position estimation session are satisfied; and cancel transmission of the SL-PRS on one or more SL-PRS resources of the set of SL-PRS resources based on the detection of the one or more session cancellation conditions and irrespective of an availability of the one or more SL-PRS resources.

[0258] Clause 65. The non-transitory computer-readable medium of clause 64, wherein, to cancel transmission of the SL-PRS, the instructions cause the UE to cancel the transmission of the SL-PRS on each SL-PRS resource of the set of SL-PRS resources that is subsequent to a time of the detection of the one or more session cancellation conditions.

[0259] Clause 66. The non-transitory computer-readable medium of any of clauses 64 to 65, further comprising computer-executable instructions that, when executed by the UE, cause the UE to: perform, before the detection of the one or more session cancellation conditions, at least one transmission of the SL-PRS on at least one SL-PRS resource of the set of SL-PRS resources. 69 QC2403139WOQualcomm Ref. No.2403139WO

[0260] Clause 67. The non-transitory computer-readable medium of any of clauses 64 to 66, wherein, to cancel transmission of the SL-PRS, the instructions cause the UE to cancel the transmission of the SL-PRS on each SL-PRS resource of the set of SL-PRS resources.

[0261] Clause 68. The non-transitory computer-readable medium of any of clauses 64 to 67, wherein the position estimation session is associated with a plurality of UEs attempting to perform SL-PRS transmissions via the SL-PRS resource pool during the time window, and wherein the plurality of UEs comprises the UE.

[0262] Clause 69. The non-transitory computer-readable medium of any of clauses 64 to 68, wherein the one or more session cancellation conditions are indicative of failure for at least one requirement associated with the position estimation session.

[0263] Clause 70. The non-transitory computer-readable medium of any of clauses 64 to 69, wherein the one or more session cancellation conditions are evaluated prior to each attempt to perform any transmission of the SL-PRS by the UE on any of the set of SL- PRS resources.

[0264] Clause 71. The non-transitory computer-readable medium of any of clauses 64 to 70, wherein the one or more session cancellation conditions are configured or pre-configured or activated or deactivated based on a configuration of the SL-PRS resource pool, or wherein the one or more session cancellation conditions are configured or pre-configured or activated or deactivated via radio resource control (RRC) signaling, or wherein the one or more session cancellation conditions are configured or pre-configured or activated or deactivated via higher-layer sidelink signaling.

[0265] Clause 72. The non-transitory computer-readable medium of any of clauses 64 to 71, wherein, to detect that one or more session cancellation conditions are satisfied, the instructions cause the UE to evaluate the one or more session cancellation conditions with respect to a given time during the time window of the position estimation session.

[0266] Clause 73. The non-transitory computer-readable medium of clause 72, wherein the one or more session cancellation conditions comprise: a total count of SL-PRS transmissions performed during the position estimation session up until the given time by any UE associated with the position estimation session being below a first threshold, or a number of UEs associated with the position estimation session that have performed at least a first number of SL-PRS transmissions during the position estimation session up until the given time being below a second threshold, or a total number of listen before talk (LBT) failures QC2403139WOQualcomm Ref. No.2403139WO by the UE during the position estimation session up until the given time being above a third threshold, or a number of remaining SL-PRS resources in the SL-PRS resource pool within the time window subsequent to the given time being insufficient for at least one UE participating in the position estimation session to perform a threshold total number of SL-PRS transmissions during the position estimation session, or a number of session cancellation notifications received during the position estimation session up until the given time from one or more other UEs participating in the position estimation session being above or below a fourth threshold, or any combination thereof.

[0267] Clause 74. The non-transitory computer-readable medium of any of clauses 72 to 73, wherein the one or more session cancellation conditions comprise at least one session criterion that is compared against a fixed threshold.

[0268] Clause 75. The non-transitory computer-readable medium of any of clauses 72 to 74, wherein the one or more session cancellation conditions comprise at least one session criterion that is compared against a dynamic threshold.

[0269] Clause 76. The non-transitory computer-readable medium of clause 75, wherein the dynamic threshold is based on a set of criteria comprising: an amount of time from a startpoint of the time window to the given time, or an amount of time from the given time to an endpoint of the time window, or a total number of UEs associated with the position estimation session attempting to perform SL-PRS transmissions during the position estimation session, or a minimum number of UEs associated with the position estimation session required to perform successful SL-PRS transmissions during the position estimation session, or a minimum number of SL-PRS transmissions to be performed per UE associated with the position estimation session that attempts to transmit SL-PRS during the position estimation session, or any combination thereof.

[0270] Clause 77. The non-transitory computer-readable medium of clause 76, wherein the set of criteria is indicated based on a configuration of the SL-PRS resource pool, or wherein the set of criteria is indicated via radio resource control (RRC) signaling, or wherein the set of criteria is indicated via higher-layer sidelink signaling.

[0271] Clause 78. The non-transitory computer-readable medium of any of clauses 64 to 77, wherein the computer-executable instructions that, when executed by the UE, cause the UE to detect comprise computer-executable instructions that, when executed by the UE, cause the UE to: identify a SL-PRS transmission from another UE on the SL-PRS QC2403139WOQualcomm Ref. No.2403139WO resource pool during the position estimation session as being associated with the position estimation session.

[0272] Clause 79. The non-transitory computer-readable medium of clause 78, wherein the identifying is based on a sidelink communication information (SCI) associated with the SL-PRS transmission from the another UE.

[0273] Clause 80. The non-transitory computer-readable medium of clause 79, wherein the identifying is based on a source identifier field of the SCI, or wherein the identifying is based on a destination identifier field of the SCI, or wherein the identifying is based on a session identifier field of the SCI, or any combination thereof.

[0274] Clause 81. The non-transitory computer-readable medium of any of clauses 78 to 80, wherein the identifying is based on reference signal received power (RSRP) measurement associated with the SL-PRS transmission from the another UE.

[0275] Clause 82. The non-transitory computer-readable medium of any of clauses 64 to 81, further comprising computer-executable instructions that, when executed by the UE, cause the UE to: transmit a session cancellation notification that indicates that the UE is canceling participation in the position estimation session.

[0276] Clause 83. The non-transitory computer-readable medium of clause 82, wherein the session cancellation notification is unicast or groupcast, or wherein the session cancellation notification comprises a session identifier associated with the position estimation session, or wherein the session cancellation notification comprises a first number of the one or more SL-PRS resources for which the transmission of the SL-PRS is canceled by the UE, or wherein the session cancellation notification comprises a second number SL-PRS transmissions performed by the UE during the position estimation session prior to the transmission of the session cancellation notification, or wherein the session cancellation notification comprises an indication of the one or more session cancellation conditions, or any combination thereof.

[0277] Clause 84. The non-transitory computer-readable medium of any of clauses 64 to 83, wherein the position estimation session corresponds to a location services (LCS) session.

[0278] Those of skill in the art will appreciate that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, QC2403139WOQualcomm Ref. No.2403139WO electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0279] Further, those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

[0280] The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an ASIC, a field-programable gate array (FPGA), or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

[0281] The methods, sequences and / or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in random access memory (RAM), flash memory, read-only memory (ROM), erasable programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An example storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In QC2403139WOQualcomm Ref. No.2403139WO the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal (e.g., UE). In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

[0282] In one or more example aspects, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A 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 RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

[0283] While the foregoing disclosure shows illustrative aspects of the disclosure, it should be noted that various changes and modifications could be made herein without departing from the scope of the disclosure as defined by the appended claims. For example, the functions, steps and / or actions of the method claims in accordance with the aspects of the disclosure described herein need not be performed in any particular order. Further, no component, function, action, or instruction described or claimed herein should be construed as critical or essential unless explicitly described as such. Furthermore, as used QC2403139WOQualcomm Ref. No.2403139WO herein, the terms “set,” “group,” and the like are intended to include one or more of the stated elements. Also, as used herein, the terms “has,” “have,” “having,” “comprises,” “comprising,” “includes,” “including,” and the like does not preclude the presence of one or more additional elements (e.g., an element “having” A may also have B). Further, the phrase “based on” is intended to mean “based, at least in part, on” unless explicitly stated otherwise. Also, as used herein, the term “or” is intended to be inclusive when used in a series and may be used interchangeably with “and / or,” unless explicitly stated otherwise (e.g., if used in combination with “either” or “only one of”) or the alternatives are mutually exclusive (e.g., “one or more” should not be interpreted as “one and more”). Furthermore, although components, functions, actions, and instructions may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Accordingly, as used herein, the articles “a,” “an,” “the,” and “said” are intended to include one or more of the stated elements. Additionally, as used herein, the terms “at least one” and “one or more” encompass “one” component, function, action, or instruction performing or capable of performing a described or claimed functionality and also “two or more” components, functions, actions, or instructions performing or capable of performing a described or claimed functionality in combination. QC2403139WO

Claims

Qualcomm Ref. No.2403139WO CLAIMS What is claimed is:

1. A user equipment (UE), comprising: one or more memories; one or more transceivers; and one or more processors communicatively coupled to the one or more memories and the one or more transceivers, the one or more processors, either alone or in combination, configured to: determine a set of sidelink positioning reference signal (SL-PRS) resources in a SL-PRS resource pool on which to transmit SL-PRS during a time window of a position estimation session; detect that one or more session cancellation conditions associated with the position estimation session are satisfied; and cancel transmission of the SL-PRS on one or more SL-PRS resources of the set of SL-PRS resources based on the detection of the one or more session cancellation conditions and irrespective of an availability of the one or more SL-PRS resources.

2. The UE of claim 1, wherein, to cancel transmission of the SL-PRS, the one or more processors are configured to cancel the transmission of the SL-PRS on each SL- PRS resource of the set of SL-PRS resources that is subsequent to a time of the detection of the one or more session cancellation conditions.

3. The UE of claim 1, wherein the one or more processors, either alone or in combination, are further configured to: perform, before the detection of the one or more session cancellation conditions, at least one transmission of the SL-PRS on at least one SL-PRS resource of the set of SL- PRS resources.

4. The UE of claim 1, wherein, to cancel transmission of the SL-PRS, the one or more processors are configured to cancel the transmission of the SL-PRS on each SL- PRS resource of the set of SL-PRS resources. 76 QC2403139WOQualcomm Ref. No.2403139WO 5. The UE of claim 1, wherein the position estimation session is associated with a plurality of UEs attempting to perform SL-PRS transmissions via the SL-PRS resource pool during the time window, and wherein the plurality of UEs comprises the UE.

6. The UE of claim 1, wherein the one or more session cancellation conditions are indicative of failure for at least one requirement associated with the position estimation session.

7. The UE of claim 1, wherein the one or more session cancellation conditions are evaluated prior to each attempt to perform any transmission of the SL-PRS by the UE on any of the set of SL-PRS resources.

8. The UE of claim 1, wherein the one or more session cancellation conditions are configured or pre- configured or activated or deactivated based on a configuration of the SL-PRS resource pool, or wherein the one or more session cancellation conditions are configured or pre- configured or activated or deactivated via radio resource control (RRC) signaling, or wherein the one or more session cancellation conditions are configured or pre- configured or activated or deactivated via higher-layer sidelink signaling.

9. The UE of claim 1, wherein, to detect that one or more session cancellation conditions are satisfied, the one or more processors are configured to evaluate the one or more session cancellation conditions with respect to a given time during the time window of the position estimation session.

10. The UE of claim 9, wherein the one or more session cancellation conditions comprise: QC2403139WOQualcomm Ref. No.2403139WO a total count of SL-PRS transmissions performed during the position estimation session up until the given time by any UE associated with the position estimation session being below a first threshold, or a number of UEs associated with the position estimation session that have performed at least a first number of SL-PRS transmissions during the position estimation session up until the given time being below a second threshold, or a total number of listen before talk (LBT) failures by the UE during the position estimation session up until the given time being above a third threshold, or a number of remaining SL-PRS resources in the SL-PRS resource pool within the time window subsequent to the given time being insufficient for at least one UE participating in the position estimation session to perform a threshold total number of SL- PRS transmissions during the position estimation session, or a number of session cancellation notifications received during the position estimation session up until the given time from one or more other UEs participating in the position estimation session being above or below a fourth threshold, or any combination thereof.

11. The UE of claim 9, wherein the one or more session cancellation conditions comprise at least one session criterion that is compared against a fixed threshold.

12. The UE of claim 9, wherein the one or more session cancellation conditions comprise at least one session criterion that is compared against a dynamic threshold.

13. The UE of claim 12, wherein the dynamic threshold is based on a set of criteria comprising: an amount of time from a startpoint of the time window to the given time, or an amount of time from the given time to an endpoint of the time window, or a total number of UEs associated with the position estimation session attempting to perform SL-PRS transmissions during the position estimation session, or 78 QC2403139WOQualcomm Ref. No.2403139WO a minimum number of UEs associated with the position estimation session required to perform successful SL-PRS transmissions during the position estimation session, or a minimum number of SL-PRS transmissions to be performed per UE associated with the position estimation session that attempts to transmit SL-PRS during the position estimation session, or any combination thereof.

14. The UE of claim 13, wherein the set of criteria is indicated based on a configuration of the SL-PRS resource pool, or wherein the set of criteria is indicated via radio resource control (RRC) signaling, or wherein the set of criteria is indicated via higher-layer sidelink signaling.

15. The UE of claim 1, wherein, to detect, the one or more processors, either alone or in combination, are configured to: identify a SL-PRS transmission from another UE on the SL-PRS resource pool during the position estimation session as being associated with the position estimation session.

16. The UE of claim 15, wherein the one or more processors are configured to identify the SL-PRS transmission from the another UE based on a sidelink communication information (SCI) associated with the SL-PRS transmission from the another UE.

17. The UE of claim 16, wherein the one or more processors are configured to identify based on: a source identifier field of the SCI, or a destination identifier field of the SCI, or a session identifier field of the SCI, or any combination thereof. 79 QC2403139WOQualcomm Ref. No.2403139WO 18. The UE of claim 15, wherein the wherein the one or more processors are configured to identify based on reference signal received power (RSRP) measurement associated with the SL-PRS transmission from the another UE.

19. The UE of claim 1, wherein the one or more processors, either alone or in combination, are further configured to: transmit, via the one or more transceivers, a session cancellation notification that indicates that the UE is canceling participation in the position estimation session.

20. The UE of claim 19, wherein the session cancellation notification is unicast or groupcast, or wherein the session cancellation notification comprises a session identifier associated with the position estimation session, or wherein the session cancellation notification comprises a first number of the one or more SL-PRS resources for which the transmission of the SL-PRS is canceled by the UE, or wherein the session cancellation notification comprises a second number SL-PRS transmissions performed by the UE during the position estimation session prior to the transmission of the session cancellation notification, or wherein the session cancellation notification comprises an indication of the one or more session cancellation conditions, or any combination thereof.

21. The UE of claim 1, wherein the position estimation session corresponds to a location services (LCS) session.

22. A method performed by a user equipment (UE), comprising: determining a set of sidelink positioning reference signal (SL-PRS) resources in a SL-PRS resource pool on which to transmit SL-PRS during a time window of a position estimation session; 80 QC2403139WOQualcomm Ref. No.2403139WO detecting that one or more session cancellation conditions associated with the position estimation session are satisfied; and canceling transmission of the SL-PRS on one or more SL-PRS resources of the set of SL-PRS resources based on the detection of the one or more session cancellation conditions and irrespective of an availability of the one or more SL-PRS resources.

23. The method of claim 22, wherein the canceling comprises canceling the transmission of the SL-PRS on each SL-PRS resource of the set of SL-PRS resources that is subsequent to a time of the detection of the one or more session cancellation conditions.

24. The method of claim 22, further comprising: performing, before the detection of the one or more session cancellation conditions, at least one transmission of the SL-PRS on at least one SL-PRS resource of the set of SL-PRS resources.

25. The method of claim 22, wherein the canceling comprises canceling the transmission of the SL-PRS on each SL-PRS resource of the set of SL-PRS resources.

26. The method of claim 22, wherein the position estimation session is associated with a plurality of UEs attempting to perform SL-PRS transmissions via the SL-PRS resource pool during the time window, and wherein the plurality of UEs comprises the UE.

27. The method of claim 22, wherein the one or more session cancellation conditions are indicative of failure for at least one requirement associated with the position estimation session.

28. The method of claim 22, wherein the one or more session cancellation conditions are evaluated prior to each attempt to perform any transmission of the SL-PRS by the UE on any of the set of SL-PRS resources. 81 QC2403139WOQualcomm Ref. No.2403139WO 29. The method of claim 22, wherein the one or more session cancellation conditions are configured or pre- configured or activated or deactivated based on a configuration of the SL-PRS resource pool, or wherein the one or more session cancellation conditions are configured or pre- configured or activated or deactivated via radio resource control (RRC) signaling, or wherein the one or more session cancellation conditions are configured or pre- configured or activated or deactivated via higher-layer sidelink signaling.

30. A user equipment (UE), comprising: means for determining a set of sidelink positioning reference signal (SL-PRS) resources in a SL-PRS resource pool on which to transmit SL-PRS during a time window of a position estimation session; means for detecting that one or more session cancellation conditions associated with the position estimation session are satisfied; and means for canceling transmission of the SL-PRS on one or more SL-PRS resources of the set of SL-PRS resources based on the detection of the one or more session cancellation conditions and irrespective of an availability of the one or more SL-PRS resources. 82 QC2403139WO

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