Patent Description:
The use of a sidelink (SL) interface in the positioning of a UE for which a position is to be determined (or "target UE") may be similar in ways to the use of base stations. However, unlike base stations, UEs used to position the target UE (or "anchor UEs") may be subject to Timing Advance (TA) commands. These commands can impact the transmission times of reference signals used to position the target UE, which, in turn, can impact the accuracy of the position estimate of the target UE. Applicable communication standards for SL-based positioning currently have no way of accounting for these TA commands. <CIT> describes techniques for a wireless access network node assigns different base sequences to respective user equipments (UEs) to use for discovery beacon signals for device-to-device (D2D) discovery. <CIT> describes systems and methods for reporting of information related to sounding reference signals (SRS) timing adjustments. The article by <NPL>, describes UE RX-TX time difference measurement requirements for NR Pos.

Further embodiments are provided by the description.

The following description is directed to certain implementations for the purposes of describing the innovative aspects of this disclosure. However, a person having ordinary skill in the art will readily recognize that the teachings herein can be applied in a multitude of different ways. The described implementations may be implemented in any device, system, or network that is capable of transmitting and receiving radio frequency (RF) signals according to any communication standard, such as any of the Institute of Electrical and Electronics Engineers (IEEE) IEEE <NUM> standards (including those identified as Wi-Fi® technologies), the Bluetooth® standard, code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), Global System for Mobile communications (GSM), GSM/General Packet Radio Service (GPRS), Enhanced Data GSM Environment (EDGE), Terrestrial Trunked Radio (TETRA), Wideband-CDMA (W-CDMA), Evolution Data Optimized (EV-DO), 1xEV-DO, EV-DO Rev A, EV-DO Rev B, High Rate Packet Data (HRPD), High Speed Packet Access (HSPA), High Speed Downlink Packet Access (HSDPA), High Speed Uplink Packet Access (HSUPA), Evolved High Speed Packet Access (HSPA+), Long Term Evolution (LTE), Advanced Mobile Phone System (AMPS), or other known signals that are used to communicate within a wireless, cellular or internet of things (IoT) network, such as a system utilizing <NUM>, <NUM>, <NUM>, <NUM>, or further implementations thereof, technology.

As used herein, an "RF signal" comprises an electromagnetic wave that transports information through the space between a transmitter (or transmitting device) and a receiver (or receiving device). 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.

<FIG> is a simplified illustration of a positioning system <NUM> in which a UE <NUM>, location server <NUM>, and/or other components of the positioning system <NUM> can use the techniques provided herein for handling Timing Advance (TA) commands when determining an estimated location of UE <NUM> using sidelink (SL)-assisted positioning, according to an embodiment. Again, when determining the position of a UE (e.g., UE <NUM>) it may be referred to as a "target UE. " The techniques described herein may be implemented by one or more components of the positioning system <NUM>. The positioning system <NUM> can include: a UE <NUM>; one or more satellites <NUM> (also referred to as space vehicles (SVs)) for a Global Navigation Satellite System (GNSS) such as the Global Positioning System (GPS), GLONASS, Galileo or Beidou; base stations <NUM>; access points (APs) <NUM>; location server <NUM>; network <NUM>; and external client <NUM>. Generally put, the positioning system <NUM> can estimate a location of the UE <NUM> based on RF signals received by and/or sent from the UE <NUM> and known locations of other components (e.g., GNSS satellites <NUM>, base stations <NUM>, APs <NUM>) transmitting and/or receiving the RF signals. Additional details regarding particular location estimation techniques are discussed in more detail with regard to <FIG>.

It should be noted that <FIG> provides only a generalized illustration of various components, any or all of which may be utilized as appropriate, and each of which may be duplicated as necessary. Specifically, although only one UE <NUM> is illustrated, it will be understood that many UEs (e.g., hundreds, thousands, millions, etc.) may utilize the positioning system <NUM>. Similarly, the positioning system <NUM> may include a larger or smaller number of base stations <NUM> and/or APs <NUM> than illustrated in <FIG>. The illustrated connections that connect the various components in the positioning system <NUM> comprise data and signaling connections which may include additional (intermediary) components, direct or indirect physical and/or wireless connections, and/or additional networks. Furthermore, components may be rearranged, combined, separated, substituted, and/or omitted, depending on desired functionality. In some embodiments, for example, the external client <NUM> may be directly connected to location server <NUM>. A person of ordinary skill in the art will recognize many modifications to the components illustrated.

Depending on desired functionality, the network <NUM> may comprise any of a variety of wireless and/or wireline networks. The network <NUM> can, for example, comprise any combination of public and/or private networks, local and/or wide-area networks, and the like. Furthermore, the network <NUM> may utilize one or more wired and/or wireless communication technologies. In some embodiments, the network <NUM> may comprise a cellular or other mobile network, a wireless local area network (WLAN), a wireless wide-area network (WWAN), and/or the Internet, for example. Examples of network <NUM> include a Long-Term Evolution (LTE) wireless network, a Fifth Generation (<NUM>) wireless network (also referred to as New Radio (NR) wireless network or <NUM> NR wireless network), a Wi-Fi WLAN, and the Internet. LTE, <NUM> and NR are wireless technologies defined, or being defined, by the 3rd Generation Partnership Project (3GPP). Network <NUM> may also include more than one network and/or more than one type of network.

The base stations <NUM> and access points (APs) <NUM> are communicatively coupled to the network <NUM>. In some embodiments, the base station <NUM> may be owned, maintained, and/or operated by a cellular network provider, and may employ any of a variety of wireless technologies, as described herein below. Depending on the technology of the network <NUM>, a base station <NUM> may comprise a node B, an Evolved Node B (eNodeB or eNB), a base transceiver station (BTS), a radio base station (RBS), an NR NodeB (gNB), a Next Generation eNB (ng-eNB), or the like. A base station <NUM> that is a gNB or ng-eNB may be part of a Next Generation Radio Access Network (NG-RAN) which may connect to a <NUM> Core Network (5GC) in the case that Network <NUM> is a <NUM> network. An AP <NUM> may comprise a Wi-Fi AP or a Bluetooth® AP, for example. Thus, UE <NUM> can send and receive information with network-connected devices, such as location server <NUM>, by accessing the network <NUM> via a base station <NUM> using a first communication link <NUM>. Additionally or alternatively, because APs <NUM> also may be communicatively coupled with the network <NUM>, UE <NUM> may communicate with network-connected and Internet-connected devices, including location server <NUM>, using a second communication link <NUM>.

As used herein, the term "base station" may generically refer to a single physical transmission point, or multiple co-located physical transmission points, which may be located at a base station <NUM>. A Transmission Reception Point (TRP) (also known as transmit/receive point) corresponds to this type of transmission point, and the term "TRP" may be used interchangeably herein with the terms "gNB," "ng-eNB," and "base station. " In some cases, a base station <NUM> may comprise multiple TRPs - e.g. with each TRP associated with a different antenna or a different antenna array for the base station <NUM>. Physical transmission points may comprise an array of antennas of a base station <NUM> (e.g., as in a Multiple Input-Multiple Output (MIMO) system and/or where the base station employs beamforming). The term "base station" may additionally refer to multiple non-co-located physical transmission points, the physical transmission points 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).

As used herein, the term "cell" may generically refer to a logical communication entity used for communication with a base station <NUM> and may be associated with an identifier for distinguishing neighboring cells (e.g., a Physical Cell Identifier (PCID), a Virtual Cell Identifier (VCID)) operating via the same or a different carrier. In some examples, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., Machine-Type Communication (MTC), Narrowband Internet-of-Things (NB-IoT), Enhanced Mobile Broadband (eMBB), or others) that may provide access for different types of devices. In some cases, the term "cell" may refer to a portion of a geographic coverage area (e.g., a sector) over which the logical entity operates.

The location server <NUM> may comprise a server and/or other computing device configured to determine an estimated location of UE <NUM> and/or provide data (e.g., "assistance data") to UE <NUM> to facilitate location measurement and/or location determination by UE <NUM>. According to some embodiments, location server <NUM> may comprise a Home Secure User Plane Location (SUPL) Location Platform (H-SLP), which may support the SUPL user plane (UP) location solution defined by the Open Mobile Alliance (OMA) and may support location services for UE <NUM> based on subscription information for UE <NUM> stored in location server <NUM>. In some embodiments, the location server <NUM> may comprise, a Discovered SLP (D-SLP) or an Emergency SLP (E-SLP). The location server <NUM> may also comprise an Enhanced Serving Mobile Location Center (E-SMLC) that supports location of UE <NUM> using a control plane (CP) location solution for LTE radio access by UE <NUM>. The location server <NUM> may further comprise a Location Management Function (LMF) that supports location of UE <NUM> using a control plane (CP) location solution for NR or LTE radio access by UE <NUM>.

In a CP location solution, signaling to control and manage the location of UE <NUM> may be exchanged between elements of network <NUM> and with UE <NUM> using existing network interfaces and protocols and as signaling from the perspective of network <NUM>. In a UP location solution, signaling to control and manage the location of UE <NUM> may be exchanged between location server <NUM> and UE <NUM> as data (e.g. data transported using the Internet Protocol (IP) and/or Transmission Control Protocol (TCP)) from the perspective of network <NUM>.

As previously noted, and as discussed in more detail below, the estimated location of UE <NUM> may be based on measurements of RF signals sent from and/or received by the UE <NUM>. In particular, these measurements can provide information regarding the relative distance and/or angle of the UE <NUM> from one or more components in the positioning system <NUM> (e.g., GNSS satellites <NUM>, APs <NUM>, base stations <NUM>). The estimated location of the UE <NUM> can be estimated geometrically (e.g., using multiangulation and/or multilateration), based on the distance and/or angle measurements, along with known position of the one or more components.

Although terrestrial components such as APs <NUM> and base stations <NUM> may be fixed, embodiments are not so limited. Mobile components may be used. Moreover, in some embodiments, a location of the UE <NUM> may be estimated at least in part based on measurements of RF signals communicated between the UE <NUM> and one or more other UEs (not shown in <FIG>), which may be mobile. Direct communication between the one or more other UEs and UE <NUM> may comprise sidelink and/or similar Device-to-Device (D2D) communication technologies. Sidelink, which is defined by 3GPP, is a form of D2D communication under the cellular-based LTE and NR standards.

An estimated location of UE <NUM> can be used in a variety of applications - e.g. to assist direction finding or navigation for a user of UE <NUM> or to assist another user (e.g. associated with external client <NUM>) to locate UE <NUM>. A "location" is also referred to herein as a "location estimate", "estimated location", "location", "position", "position estimate", "position fix", "estimated position", "location fix" or "fix". A location of UE <NUM> may comprise an absolute location of UE <NUM> (e.g. a latitude and longitude and possibly altitude) or a relative location of UE <NUM> (e.g. a location expressed as distances north or south, east or west and possibly above or below some other known fixed location or some other location such as a location for UE <NUM> at some known previous time). A location may be specified as a geodetic location comprising coordinates which may be absolute (e.g. latitude, longitude and optionally altitude), relative (e.g. relative to some known absolute location) or local (e.g. X, Y and optionally Z coordinates according to a coordinate system defined relative to a local area such a factory, warehouse, college campus, shopping mall, sports stadium or convention center). A location may instead be a civic location and may then comprise one or more of a street address (e.g. including names or labels for a country, state, county, city, road and/or street, and/or a road or street number), and/or a label or name for a place, building, portion of a building, floor of a building, and/or room inside a building etc. A location may further include an uncertainty or error indication, such as a horizontal and possibly vertical distance by which the location is expected to be in error or an indication of an area or volume (e.g. a circle or ellipse) within which UE <NUM> is expected to be located with some level of confidence (e.g. <NUM>% confidence).

The external client <NUM> may be a web server or remote application that may have some association with UE <NUM> (e.g. may be accessed by a user of UE <NUM>) or may be a server, application, or computer system providing a location service to some other user or users which may include obtaining and providing the location of UE <NUM> (e.g. to enable a service such as friend or relative finder, asset tracking or child or pet location). Additionally or alternatively, the external client <NUM> may obtain and provide the location of UE <NUM> to an emergency services provider, government agency, etc..

As previously noted, the example positioning system <NUM> can be implemented using a wireless communication network, such as an LTE-based or <NUM> NR-based network. <FIG> shows a diagram of a <NUM> NR positioning system <NUM>, illustrating an embodiment of a positioning system (e.g., positioning system <NUM>) implementing <NUM> NR. The <NUM> NR positioning system <NUM> may be configured to determine the location of a UE <NUM> by using access nodes <NUM>, <NUM>, <NUM> (which may correspond with base stations <NUM> and access points <NUM> of <FIG>) and (optionally) an LMF <NUM> (which may correspond with location server <NUM>) to implement one or more positioning methods. Here, the <NUM> NR positioning system <NUM> comprises a UE <NUM>, and components of a <NUM> NR network comprising a Next Generation (NG) Radio Access Network (RAN) (NG-RAN) <NUM> and a <NUM> Core Network (<NUM> CN) <NUM>. A <NUM> network may also be referred to as an NR network; NG-RAN <NUM> may be referred to as a <NUM> RAN or as an NR RAN; and <NUM> CN <NUM> may be referred to as an NG Core network. The <NUM> NR positioning system <NUM> may further utilize information from GNSS satellites <NUM> from a GNSS system like Global Positioning System (GPS) or similar system (e.g. GLONASS, Galileo, Beidou, Indian Regional Navigational Satellite System (IRNSS)). Additional components of the <NUM> NR positioning system <NUM> are described below. The <NUM> NR positioning system <NUM> may include additional or alternative components.

It should be noted that <FIG> provides only a generalized illustration of various components, any or all of which may be utilized as appropriate, and each of which may be duplicated or omitted as necessary. Specifically, although only one UE <NUM> is illustrated, it will be understood that many UEs (e.g., hundreds, thousands, millions, etc.) may utilize the <NUM> NR positioning system <NUM>. Similarly, the <NUM> NR positioning system <NUM> may include a larger (or smaller) number of GNSS satellites <NUM>, gNBs <NUM>, ng-eNBs <NUM>, Wireless Local Area Networks (WLANs) <NUM>, Access and mobility Management Functions (AMF)s <NUM>, external clients <NUM>, and/or other components. The illustrated connections that connect the various components in the <NUM> NR positioning system <NUM> include data and signaling connections which may include additional (intermediary) components, direct or indirect physical and/or wireless connections, and/or additional networks. Furthermore, components may be rearranged, combined, separated, substituted, and/or omitted, depending on desired functionality.

The UE <NUM> may comprise and/or be referred to as a device, a mobile device, a wireless device, a mobile terminal, a terminal, a mobile station (MS), a Secure User Plane Location (SUPL)-Enabled Terminal (SET), or by some other name. Moreover, UE <NUM> may correspond to a cellphone, smartphone, laptop, tablet, personal data assistant (PDA), tracking device, navigation device, Internet of Things (IoT) device, or some other portable or moveable device. Typically, though not necessarily, the UE <NUM> may support wireless communication using one or more Radio Access Technologies (RATs) such as using GSM, CDMA, W-CDMA, LTE, High Rate Packet Data (HRPD), IEEE <NUM> Wi-Fi®, Bluetooth, Worldwide Interoperability for Microwave Access (WiMAX™), <NUM> NR (e.g., using the NG-RAN <NUM> and <NUM> CN <NUM>), etc. The UE <NUM> may also support wireless communication using a WLAN <NUM> which (like the one or more RATs, and as previously noted with respect to <FIG>) may connect to other networks, such as the Internet. The use of one or more of these RATs may allow the UE <NUM> to communicate with an external client <NUM> (e.g., via elements of <NUM> CN <NUM> not shown in <FIG>, or possibly via a Gateway Mobile Location Center (GMLC) <NUM>) and/or allow the external client <NUM> to receive location information regarding the UE <NUM> (e.g., via the GMLC <NUM>). The external client <NUM> of <FIG> may correspond to external client <NUM> of <FIG>, as implemented in or communicatively coupled with a <NUM> NR network.

The UE <NUM> may include a single entity or may include multiple entities, such as in a personal area network where a user may employ audio, video and/or data I/O devices, and/or body sensors and a separate wireline or wireless modem. An estimate of a location of the UE <NUM> may be referred to as a location, location estimate, location fix, fix, position, position estimate, or position fix, and may be geodetic, thus providing location coordinates for the UE <NUM> (e.g., latitude and longitude), which may or may not include an altitude component (e.g., height above sea level, height above or depth below ground level, floor level or basement level). Alternatively, a location of the UE <NUM> may be expressed as a civic location (e.g., as a postal address or the designation of some point or small area in a building such as a particular room or floor). A location of the UE <NUM> may also be expressed as an area or volume (defined either geodetically or in civic form) within which the UE <NUM> is expected to be located with some probability or confidence level (e.g., <NUM>%, <NUM>%, etc.). A location of the UE <NUM> may further be a relative location comprising, for example, a distance and direction or relative X, Y (and Z) coordinates defined relative to some origin at a known location which may be defined geodetically, in civic terms, or by reference to a point, area, or volume indicated on a map, floor plan or building plan. In the description contained herein, the use of the term location may comprise any of these variants unless indicated otherwise. When computing the location of a UE, it is common to solve for local X, Y, and possibly Z coordinates and then, if needed, convert the local coordinates into absolute ones (e.g. for latitude, longitude and altitude above or below mean sea level).

Base stations in the NG-RAN <NUM> shown in <FIG> may correspond to base stations <NUM> in <FIG> and may include NR NodeB (gNB) <NUM>-<NUM> and <NUM>-<NUM> (collectively and generically referred to herein as gNBs <NUM>). Pairs of gNBs <NUM> in NG-RAN <NUM> may be connected to one another (e.g., directly as shown in <FIG> or indirectly via other gNBs <NUM>). Access to the <NUM> network is provided to UE <NUM> via wireless communication between the UE <NUM> and one or more of the gNBs <NUM>, which may provide wireless communications access to the <NUM> CN <NUM> on behalf of the UE <NUM> using <NUM> NR. <NUM> NR radio access may also be referred to as NR radio access or as <NUM> radio access. In <FIG>, the serving gNB for UE <NUM> is assumed to be gNB <NUM>-<NUM>, although other gNBs (e.g. gNB <NUM>-<NUM>) may act as a serving gNB if UE <NUM> moves to another location or may act as a secondary gNB to provide additional throughput and bandwidth to UE <NUM>.

Base stations in the NG-RAN <NUM> shown in <FIG> may also or instead include a next generation evolved Node B, also referred to as an ng-eNB, <NUM>. Ng-eNB <NUM> may be connected to one or more gNBs <NUM> in NG-RAN <NUM>-e.g. directly or indirectly via other gNBs <NUM> and/or other ng-eNBs. An ng-eNB <NUM> may provide LTE wireless access and/or evolved LTE (eLTE) wireless access to UE <NUM>. Some gNBs <NUM> (e.g. gNB <NUM>-<NUM>) and/or ng-eNB <NUM> in <FIG> may be configured to function as positioning-only beacons which may transmit signals (e.g., Positioning Reference Signal (PRS)) and/or may broadcast assistance data to assist positioning of UE <NUM> but may not receive signals from UE <NUM> or from other UEs. It is noted that while only one ng-eNB <NUM> is shown in <FIG>, some embodiments may include multiple ng-eNBs <NUM>. Base stations <NUM>, <NUM> may communicate directly with one another via an Xn communication interface. Additionally or alternatively, base stations <NUM>, <NUM> may communicate directly or indirectly with other components of the <NUM> NR positioning system <NUM>, such as the LMF <NUM> and AMF <NUM>.

<NUM> NR positioning system <NUM> may also include one or more WLANs <NUM> which may connect to a Non-3GPP InterWorking Function (N3IWF) <NUM> in the <NUM> CN <NUM> (e.g., in the case of an untrusted WLAN <NUM>). For example, the WLAN <NUM> may support IEEE <NUM> Wi-Fi access for UE <NUM> and may comprise one or more Wi-Fi APs (e.g., APs <NUM> of <FIG>). Here, the N3IWF <NUM> may connect to other elements in the <NUM> CN <NUM> such as AMF <NUM>. In some embodiments, WLAN <NUM> may support another RAT such as Bluetooth. The N3IWF <NUM> may provide support for secure access by UE <NUM> to other elements in <NUM> CN <NUM> and/or may support interworking of one or more protocols used by WLAN <NUM> and UE <NUM> to one or more protocols used by other elements of <NUM> CN <NUM> such as AMF <NUM>. For example, N3IWF <NUM> may support IPSec tunnel establishment with UE <NUM>, termination of IKEv2/IPSec protocols with UE <NUM>, termination of N2 and N3 interfaces to <NUM> CN <NUM> for control plane and user plane, respectively, relaying of uplink (UL) and downlink (DL) control plane Non-Access Stratum (NAS) signaling between UE <NUM> and AMF <NUM> across an N1 interface. In some other embodiments, WLAN <NUM> may connect directly to elements in <NUM> CN <NUM> (e.g. AMF <NUM> as shown by the dashed line in <FIG>) and not via N3IWF <NUM>. For example, direct connection of WLAN <NUM> to 5GCN <NUM> may occur if WLAN <NUM> is a trusted WLAN for 5GCN <NUM> and may be enabled using a Trusted WLAN Interworking Function (TWIF) (not shown in <FIG>) which may be an element inside WLAN <NUM>. It is noted that while only one WLAN <NUM> is shown in <FIG>, some embodiments may include multiple WLANs <NUM>.

Access nodes may comprise any of a variety of network entities enabling communication between the UE <NUM> and the AMF <NUM>. This can include gNBs <NUM>, ng-eNB <NUM>, WLAN <NUM>, and/or other types of cellular base stations. However, access nodes providing the functionality described herein may additionally or alternatively include entities enabling communications to any of a variety of RATs not illustrated in <FIG>, which may include non-cellular technologies. Thus, the term "access node," as used in the embodiments described herein below, may include but is not necessarily limited to a gNB <NUM>, ng-eNB <NUM> or WLAN <NUM>.

In some embodiments, an access node, such as a gNB <NUM>, ng-eNB <NUM>, or WLAN <NUM> (alone or in combination with other components of the <NUM> NR positioning system <NUM>), may be configured to, in response to receiving a request for location information from the LMF <NUM>, obtain location measurements of uplink (UL) signals received from the UE <NUM>) and/or obtain downlink (DL) location measurements from the UE <NUM> that were obtained by UE <NUM> for DL signals received by UE <NUM> from one or more ANs. As noted, while <FIG> depicts access nodes <NUM>, <NUM>, and <NUM> configured to communicate according to <NUM> NR, LTE, and Wi-Fi communication protocols, respectively, access nodes configured to communicate according to other communication protocols may be used, such as, for example, a Node B using a Wideband Code Division Multiple Access (WCDMA) protocol for a Universal Mobile Telecommunications Service (UMTS) Terrestrial Radio Access Network (UTRAN), an eNB using an LTE protocol for an Evolved UTRAN (E-UTRAN), or a Bluetooth® beacon using a Bluetooth protocol for a WLAN. For example, in a <NUM> Evolved Packet System (EPS) providing LTE wireless access to UE <NUM>, a RAN may comprise an E-UTRAN, which may comprise base stations comprising eNBs supporting LTE wireless access. A core network for EPS may comprise an Evolved Packet Core (EPC). An EPS may then comprise an E-UTRAN plus an EPC, where the E-UTRAN corresponds to NG-RAN <NUM> and the EPC corresponds to 5GCN <NUM> in <FIG>. The methods and techniques described herein for obtaining a civic location for UE <NUM> may be applicable to such other networks.

The gNBs <NUM> and ng-eNB <NUM> can communicate with an AMF <NUM>, which, for positioning functionality, communicates with an LMF <NUM>. The AMF <NUM> may support mobility of the UE <NUM>, including cell change and handover of UE <NUM> from an access node <NUM>, <NUM>, or <NUM> of a first RAT to an access node <NUM>, <NUM>, or <NUM> of a second RAT. The AMF <NUM> may also participate in supporting a signaling connection to the UE <NUM> and possibly data and voice bearers for the UE <NUM>. The LMF <NUM> may support positioning of the UE <NUM> using a CP location solution when UE <NUM> accesses the NG-RAN <NUM> or WLAN <NUM> and may support position procedures and methods, including UE assisted/UE based and/or network based procedures/methods, such as Assisted GNSS (A-GNSS), Observed Time Difference Of Arrival (OTDOA) (which may be referred to in NR as Time Difference Of Arrival (TDOA) or DL-TDOA), Real Time Kinematic (RTK), Precise Point Positioning (PPP), Differential GNSS (DGNSS), Enhance Cell ID (ECID), angle of arrival (AOA), angle of departure (AOD), WLAN positioning, round trip signal propagation delay (RTT), multi-cell RTT, and/or other positioning procedures and methods. The LMF <NUM> may also process location service requests for the UE <NUM>, e.g., received from the AMF <NUM> or from the GMLC <NUM>. The LMF <NUM> may be connected to AMF <NUM> and/or to GMLC <NUM>. In some embodiments, a network such as 5GCN <NUM> may additionally or alternatively implement other types of location-support modules, such as an Evolved Serving Mobile Location Center (E-SMLC) or a SUPL Location Platform (SLP). It is noted that in some embodiments, at least part of the positioning functionality (including determination of a UE <NUM>'s location) may be performed at the UE <NUM> (e.g., by measuring downlink PRS (DL-PRS) signals transmitted by wireless nodes such as gNBs <NUM>, ng-eNB <NUM> and/or WLAN <NUM>, and/or using assistance data provided to the UE <NUM>, e.g., by LMF <NUM>).

The Gateway Mobile Location Center (GMLC) <NUM> may support a location request for the UE <NUM> received from an external client <NUM> and may forward such a location request to the AMF <NUM> for forwarding by the AMF <NUM> to the LMF <NUM>. A location response from the LMF <NUM> (e.g., containing a location estimate for the UE <NUM>) may be similarly returned to the GMLC <NUM> either directly or via the AMF <NUM>, and the GMLC <NUM> may then return the location response (e.g., containing the location estimate) to the external client <NUM>.

A Network Exposure Function (NEF) <NUM> may be included in 5GCN <NUM>. The NEF <NUM> may support secure exposure of capabilities and events concerning 5GCN <NUM> and UE <NUM> to the external client <NUM>, which may then be referred to as an Access Function (AF) and may enable secure provision of information from external client <NUM> to 5GCN <NUM>. NEF <NUM> may be connected to AMF <NUM> and/or to GMLC <NUM> for the purposes of obtaining a location (e.g. a civic location) of UE <NUM> and providing the location to external client <NUM>.

As further illustrated in <FIG>, the LMF <NUM> may communicate with the gNBs <NUM> and/or with the ng-eNB <NUM> using an NR Positioning Protocol A (NRPPa) as defined in 3GPP Technical Specification (TS) <NUM>. NRPPa messages may be transferred between a gNB <NUM> and the LMF <NUM>, and/or between an ng-eNB <NUM> and the LMF <NUM>, via the AMF <NUM>. As further illustrated in <FIG>, LMF <NUM> and UE <NUM> may communicate using an LTE Positioning Protocol (LPP) as defined in 3GPP TS <NUM>. Here, LPP messages may be transferred between the UE <NUM> and the LMF <NUM> via the AMF <NUM> and a serving gNB <NUM>-<NUM> or serving ng-eNB <NUM> for UE <NUM>. For example, LPP messages may be transferred between the LMF <NUM> and the AMF <NUM> using messages for service-based operations (e.g., based on the Hypertext Transfer Protocol (HTTP)) and may be transferred between the AMF <NUM> and the UE <NUM> using a <NUM> NAS protocol. The LPP protocol may be used to support positioning of UE <NUM> using UE assisted and/or UE based position methods such as A-GNSS, RTK, OTDOA, multi-cell RTT, AOD, and/or ECID. The NRPPa protocol may be used to support positioning of UE <NUM> using network based position methods such as ECID, AOA, uplink TDOA (UL-TDOA) and/or may be used by LMF <NUM> to obtain location related information from gNBs <NUM> and/or ng-eNB <NUM>, such as parameters defining DL-PRS transmission from gNBs <NUM> and/or ng-eNB <NUM>.

In the case of UE <NUM> access to WLAN <NUM>, LMF <NUM> may use NRPPa and/or LPP to obtain a location of UE <NUM> in a similar manner to that just described for UE <NUM> access to a gNB <NUM> or ng-eNB <NUM>. Thus, NRPPa messages may be transferred between a WLAN <NUM> and the LMF <NUM>, via the AMF <NUM> and N3IWF <NUM> to support network-based positioning of UE <NUM> and/or transfer of other location information from WLAN <NUM> to LMF <NUM>. Alternatively, NRPPa messages may be transferred between N3IWF <NUM> and the LMF <NUM>, via the AMF <NUM>, to support network-based positioning of UE <NUM> based on location related information and/or location measurements known to or accessible to N3IWF <NUM> and transferred from N3IWF <NUM> to LMF <NUM> using NRPPa. Similarly, LPP and/or LPP messages may be transferred between the UE <NUM> and the LMF <NUM> via the AMF <NUM>, N3IWF <NUM>, and serving WLAN <NUM> for UE <NUM> to support UE assisted or UE based positioning of UE <NUM> by LMF <NUM>.

In a <NUM> NR positioning system <NUM>, positioning methods can be categorized as being "UE assisted" or "UE based. " This may depend on where the request for determining the position of the UE <NUM> originated. If, for example, the request originated at the UE (e.g., from an application, or "app," executed by the UE), the positioning method may be categorized as being UE based. If, on the other hand, the request originates from an external client or AF <NUM>, LMF <NUM>, or other device or service within the <NUM> network, the positioning method may be categorized as being UE assisted (or "network-based").

With a UE-assisted position method, UE <NUM> may obtain location measurements and send the measurements to a location server (e.g., LMF <NUM>) for computation of a location estimate for UE <NUM>. For RAT-dependent position methods location measurements may include one or more of a Received Signal Strength Indicator (RSSI), Round Trip signal propagation Time (RTT), Reference Signal Received Power (RSRP), Reference Signal Received Quality (RSRQ), Reference Signal Time Difference (RSTD), Time of Arrival (TOA), AOA, Receive Time-Transmission Time Difference (Rx-Tx), Differential AOA (DAOA), AOD, or Timing Advance (TA) for gNBs <NUM>, ng-eNB <NUM>, and/or one or more access points for WLAN <NUM>. Additionally or alternatively, similar measurements may be made of sidelink signals transmitted by other UEs, which may serve as anchor points for positioning of the UE <NUM> if the positions of the other UEs are known. The location measurements may also or instead include measurements for RAT-independent positioning methods such as GNSS (e.g., GNSS pseudorange, GNSS code phase, and/or GNSS carrier phase for GNSS satellites <NUM>), WLAN, etc..

With a UE-based position method, UE <NUM> may obtain location measurements (e.g., which may be the same as or similar to location measurements for a UE assisted position method) and may further compute a location of UE <NUM> (e.g., with the help of assistance data received from a location server such as LMF <NUM>, an SLP, or broadcast by gNBs <NUM>, ng-eNB <NUM>, or WLAN <NUM>).

With a network based position method, one or more base stations (e.g., gNBs <NUM> and/or ng-eNB <NUM>), one or more APs (e.g., in WLAN <NUM>), or N3IWF <NUM> may obtain location measurements (e.g., measurements of RSSI, RTT, RSRP, RSRQ, AOA, or TOA) for signals transmitted by UE <NUM>, and/or may receive measurements obtained by UE <NUM> or by an AP in WLAN <NUM> in the case of N3IWF <NUM>, and may send the measurements to a location server (e.g., LMF <NUM>) for computation of a location estimate for UE <NUM>.

Positioning of the UE <NUM> also may be categorized as UL, DL, or DL-UL based, depending on the types of signals used for positioning. If, for example, positioning is based solely on signals received at the UE <NUM> (e.g., from a base station or other UE), the positioning may be categorized as DL based. On the other hand, if positioning is based solely on signals transmitted by the UE <NUM> (which may be received by a base station or other UE, for example), the positioning may be categorized as UL based. Positioning that is DL-UL based includes positioning, such as RTT-based positioning, that is based on signals that are both transmitted and received by the UE <NUM>.

Depending on the type of positioning (e.g., UL, DL, or DL-UL based) the types of reference signals used can vary. For DL-based positioning, for example, these signals may comprise PRS (e.g., DL-PRS transmitted by base stations or SL-PRS transmitted by other UEs), which can be used for OTDOA, AOD, and RTT measurements. Other reference signals that can be used for positioning (UL, DL, or DL-UL) may include Sounding Reference Signal (SRS), Channel State Information Reference Signal (CSI-RS), synchronization signals (e.g., synchronization signal block (SSB) Synchronizations Signal (SS)), Physical Uplink Control Channel (PUCCH), Physical Uplink Shared Channel (PUSCH), Physical Sidelink Shared Channel (PSSCH), Demodulation Reference Signal (DMRS), etc. Moreover, reference signals may be transmitted in a Tx beam and/or received in an Rx beam (e.g., using beamforming techniques), which may impact angular measurements, such as AOD and/or AOA.

<FIG> is an illustration how TDOA-based positioning can be made, according to some embodiments. In brief, TDOA-based positioning is positioning made based on known positions of TRPs (e.g., TRPs <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM>, collectively and generically referred to herein as TRPs <NUM>), known times at which TRPs transmit respective reference signals (e.g., PRS), and differences in times at which the UE <NUM> receives the reference signals from each TRP. Again, a TRP may correspond with a base station, such as base stations <NUM> of <FIG>. In a <NUM> NR positioning system <NUM>, a TRP may include a gNB <NUM> and/or ng-eNB <NUM>, as illustrated in <FIG>.

In TDOA-based positioning, a location server may provide TDOA assistance data to a UE P105 for a reference TRP (which may be called a "reference cell" or "reference resource"), and one or more neighboring TRPs (which may be called "neighbor cells" or "neighboring cells", and which individually may be called a "target cell" or "target resource") relative to the reference TRP. For example, the assistance data may provide the center channel frequency of each TRP, various PRS configuration parameters (e.g., NPRS, TPRS, muting sequence, frequency hopping sequence, PRS ID, PRS bandwidth), a TRP (cell) global ID, PRS signal characteristics associated with a directional PRS, and/or other TRP related parameters applicable to TDOA or some other position method. TDOA-based positioning by a UE <NUM> may be facilitated by indicating the serving TRP for the UE <NUM> in the TDOA assistance data (e.g., with the reference TRP indicated as being the serving TRP). In some aspects, TDOA assistance data may also include "expected Reference Signal Time Difference (RSTD)" parameters, which provide the UE <NUM> with information about the RSTD values the UE <NUM> is expected to measure at its current location between the reference TRP and each neighbor TRP, together with an uncertainty of the expected RSTD parameter. The expected RSTD, together with the associated uncertainty, may define a search window for the UE <NUM> within which the UE <NUM> is expected to measure the RSTD value. TDOA assistance information may also include PRS configuration information parameters, which allow a UE <NUM> to determine when a PRS positioning occasion occurs on signals received from various neighbor TRPs relative to PRS positioning occasions for the reference TRP, and to determine the PRS sequence transmitted from various TRPs in order to measure a time of arrival (TOA) or RSTD. TOA measurements may be RSRP (Reference Signal Receive Power) measurements of average power of Resource Elements (RE) that carry PRS (or other reference signals).

Using the RSTD measurements, the known absolute or relative transmission timing of each TRP, and the known position(s) of wireless node physical transmitting antennas for the reference and neighboring TRPs, the UE position may be calculated (e.g., by the UE <NUM> or by a location server). More particularly, the RSTD for a neighbor TRP "k" relative to a reference TRP "Ref," may be given as the difference in TOA measurements of signals from each TRP (i.e., TOAk - TOARef), where the TOA values may be measured modulo one subframe duration (<NUM>) to remove the effects of measuring different subframes at different times. In <FIG>, for example, a first TRP <NUM>-<NUM> may be designated as the reference TRP, and second and third TRPs (P110-<NUM> and <NUM>-<NUM>) are neighbor TRPs. If UE <NUM> receives reference signals from first TRP <NUM>-<NUM>, second TRP <NUM>-<NUM>, and third TRP <NUM>-<NUM> at times T1, T2, and T2, respectively, then the RSTD measurement for second TRP <NUM>-<NUM> would be determined as T2-T1 and the RSTD measurement for third TRP <NUM>-<NUM> would be determined as T3-T1. RSTD measurements can be used by the UE <NUM> and/or sent to a location server to determine the location of the UE <NUM> using (i) the RSTD measurements, (ii) the known absolute or relative transmission timing of each TRP, (iii) the known position(s) of TRPs <NUM> for the reference and neighboring TRPs, and/or (iv) directional PRS characteristics such as a direction of transmission. Geometrically, information (i)-(iv) allows for possible locations of the UE <NUM> to be determined for each RSTD (where each RSTD results in a hyperbola, as shown in <FIG>), and the position of the UE <NUM> to be determined from the intersection of the possible locations for all RSTDs.

<FIG> is an illustration how RTT-based positioning (or multi-RTT) can be made, according to some embodiments. In brief, RTT-based positioning includes positioning methods in which the position of the UE <NUM> is determined based on known positions of TRPs (e.g., TRPs <NUM>, which again may correspond to gNBs <NUM> and/or ng-eNB <NUM> of <FIG>) and known distances between the UE <NUM> and the TRPs. RTT measurements between the UE <NUM> and each TRP are used to determine a distance between the UE <NUM> and the respective TRP, and multilateration can be used to determine the location of the UE <NUM>.

In RTT-based positioning, a location server may coordinate RTT measurements between the UE <NUM> and each TRP. Information provided to the UE <NUM> may be included in RTT assistance data. This can include, for example, reference signal (e.g., PRS) timing and other signal characteristics, TRP (cell) ID, and/or other cell related parameters applicable to multi-RTT or some other position method. Depending on desired functionality, RTT measurements may be made (and initiated by) the UE <NUM> or a TRP <NUM>.

RTT measurements measure distance using Over The Air (OTA) delay. An initiating device (e.g., the UE <NUM> or a TRP <NUM>) transmits a first reference signal at first time, T1, which propagates to a responding device. At a second time, T2, the first reference signal arrives at the responding device. The OTA delay (i.e., the propagation time it takes for the first reference signal to travel from the initiating device to the responding device) is the difference between T1 and T2. The responding device then transmits a second reference signal at a third time, T3, and the second reference signal is received and measured by the initiating device at a fourth time, T4. RSRP measurements may be used to determine TOA for times T2 and T4. Distance, d, between the initiating and responding devices therefore can be determined using the following equation: <MAT> (As will be appreciated, distance, d, divided by the speed of RF propagation, c, equals the OTA delay. ) Thus, a precise determination of the distance between the initiating device and responding device can be made.

RTT measurements between the UE <NUM> and TRPs <NUM> can therefore allow the position of the UE <NUM> to be determined using multilateration. That is, RTT measurements between the UE <NUM> and the first TRP <NUM>-<NUM>, second TRP <NUM>-<NUM>, and third TRP <NUM>-<NUM> (RTT measurements RTT1, RTT2, and RTT3, respectively) result in a determination of the distance of the UE <NUM> from each of the TRPs <NUM>. These distances can be used to trace circles around known positions of the TRPs <NUM> (where Circle1 corresponds to TRP <NUM>-<NUM>, Circle2 corresponds to TRP <NUM>-<NUM>, and Circle3 corresponds to TRP <NUM>-<NUM>. ) The position of the UE <NUM> can be determined as the intersection between the circles.

<FIG> is a simplified diagram illustrating how an anchor UE <NUM> can be used in the positioning of a target UE <NUM> in a <NUM> NR network, according to an embodiment. Here, arrows between the various components illustrate communication links. As illustrated in <FIG>, this may involve wireless and/or wired communication technologies and may include one or more intermediary components. TRPs <NUM>-<NUM>, <NUM>-<NUM>, <NUM>-<NUM>, and <NUM>-<NUM> may be referred to collectively or generically referred to as TRP(s) <NUM>. For simplicity, a single anchor UE <NUM> is illustrated. However, although only one anchor UE <NUM> may be used in some instances, other instances may use two or more. Moreover, in some instances, anchor UEs <NUM> may comprise the only type of anchor point for positioning and/or TRPs <NUM> may not be used as anchor points. (As used herein, the term "anchor point" refers to a device with a known location used to determine the location of the target UE <NUM>. ) Further, although anchor UE <NUM> and target UE <NUM> are illustrated as having separate serving TRPs (TRP <NUM>-<NUM> and TRP <NUM>-<NUM>, respectively), embodiments are not so limited. In some scenarios, for example, target UE <NUM> and anchor UE <NUM> may share a common serving TRP <NUM>.

To determine the position of the target UE <NUM> (e.g., using any of the previously-described positioning techniques) the target UE <NUM> can take measurements of wireless signals sent from different anchor points: TRPs <NUM>-<NUM> to <NUM>-<NUM> and anchor UE <NUM>. The target UE <NUM> can communicate with and/or obtain measurements from TRP <NUM>-<NUM> to TRP <NUM>-<NUM> using a Uu (network) interface <NUM>. Measurements may be made from reference signals from the TRPs <NUM>, such as PRS (e.g., DL-PRS). With regard to anchor UE <NUM>, target UE <NUM> can communicate using SL interface <NUM>. As previously noted, and SL interface <NUM> allows direct (D2D) communication between the target UE <NUM> and anchor UE <NUM>, and may be used in a manner similar to the Uu interfaces <NUM>, allowing the target UE <NUM> to obtain position-related measurements in relation to determining the location of the target UE <NUM>. As such, the anchor UE <NUM> may be configured to provide a PRS (e.g., SL-PRS) and/or similar reference signal via the SL interface <NUM>, which may be transmitted in a manner similar to a TRP. For its part, the anchor UE <NUM> may also communicate with the LMF <NUM> via TRP <NUM>-<NUM> using a Uu interface <NUM>. As noted, TRP <NUM>-<NUM> may comprise the serving TRP for anchor UE <NUM> in this example.

The use of an anchor UE <NUM> in the positioning of the target UE <NUM> is similar to the use of base stations in <FIG> and <FIG> for TDOA-based and RTT-based positioning. The use of anchor UEs <NUM> in this manner can be beneficial, providing additional accuracy to a position estimate of the target UE <NUM> and/or enabling for a threshold number of anchor points in cases where the target UE <NUM> is unable to communicate with a sufficient number of TRPs <NUM> for positioning (e.g., fewer than three). However, as noted, an anchor UE <NUM> may be subject to a Timing Advance (TA) command which, if received and applied during a positioning session of the target UE <NUM>, can impact the timing of the transmission of SL-PRS via the SL interface <NUM>. This can, in turn, impact the reliability and accuracy of the position estimate for the target UE <NUM>.

TA is used to control the uplink transmission timing of a UE. This can help ensure UE transmissions from multiple UEs are synchronized with a serving TRP when the transmissions are received by the serving TRP. To maintain this synchronization, the serving TRP can issue TA commands to a UE to cause the UE to make TA adjustments to stay in synchronization. These TA commands can be issued by the TRP, for example, when the propagation delay between the UE and TRP changes, which can result from movement by the UE. Although it is primarily applicable to PUSCH, PUCCH, and SRS signals, it can impact the transmission time of an SL-PRS if received during an SL-PRS positioning session between UEs. In particular, an SL-PRS transmitted by an anchor UE <NUM> may include a timestamp to allow a target UE <NUM> or location server to accurately calculate an RTT or TDOA measurement based on the SL-PRS. However, TA-related adjustments may not be accurately reflected in timestamps and may therefore result in inaccurate measurements and ultimately the inaccurate positioning of the target UE <NUM>. <FIG> and <FIG> illustrate two examples.

<FIG> is a timing diagram illustrating an RTT exchange <NUM> between two UEs, which may occur over an SL interface <NUM> (<FIG>) during RTT-based, SL-assisted positioning of a UE. Here, UE <NUM> may correspond with a target UE <NUM> and UE two may correspond with an anchor UE <NUM>, but embodiments are not so limited. Transmission/reception times T1-T4 correspond with those previously described with respect to RTT-based positioning (e.g., times T1-T4 in equation (<NUM>)). This RTT exchange <NUM> may occur during an SL-PRS positioning session between the UE <NUM> and UE <NUM>. Timing and other aspects of the RTT exchange <NUM> may be based on an SL-PRS configuration received by the UEs from a TRP and/or location server (e.g., LMF <NUM>).

In this example, UE1 transmits a first SL-PRS <NUM> at time T1, which is received by UE2 at time T2. UE2 is configured to transmit a second SL-PRS <NUM>-<NUM> at time T3, which would be received by UE1 at time T4. However, UE2 receives a TA command <NUM> that UE2 applies between times T2 and T3. In this case, this causes a delay of Δ. Thus, rather than transmitting the SL-PRS <NUM>-<NUM> at time T3, UE2 transmits an SL-PRS <NUM>-<NUM> at time T3 + Δ. It can be noted that, depending on the TA adjustment made by UE2 in response to the TA command <NUM>, Δ may not necessarily result in a delay in the transmission of SL-PRS <NUM>-<NUM> as illustrated in <FIG>. In other instances, for example, Δ could be a negative value resulting in an earlier transmission.

The value of Δ can lead to an inaccurate RTT measurement (and, resultantly, an inaccurate determination of distance between UE1 and UE2) if unaccounted for. In particular, Δ may be combined with clock drift between T1 and T2, which can result in an inaccurate Rx-Tx measurement by UE2 used to determine the RTT measurement. This inaccurate Rx-Tx measurement can, in turn, cause errors in the determination of a location for UE <NUM>, for example.

Furthermore, accounting for Δ in the calculation of the RTT measurement may not be straightforward. The RTT measurement may be calculated at UE1 (e.g., using equation (<NUM>) above) or at a location server that receives times T1-T4 from UE1. However, TA commands are UE-specific, typically provided to the UE by the UE's serving TRP via random access channel (RACH) response (e.g., during handover of the UE from one cell to another) or via Medium Access Control (MAC) Control Element (CE) (MAC-CE). As such, UE1 and the location server are unaware of TA commands received by UE2 and are thereby unable to account for TA adjustments during the RTT exchange <NUM>.

<FIG> is a timing diagram illustrating a TDOA-based measurement <NUM> using two UEs, similar to <FIG>. Again, this may take place over an SL interface <NUM> (<FIG>) during TDOA-based, SL-assisted positioning of a UE. In this example, the TDOA-based measurement <NUM> is based on a series of SL-PRS transmitted by UE2 and received by UE1. However, after transmitting a SL-PRS <NUM> at time T1 and before transmitting a SL-PRS <NUM>-<NUM> at time T2, UE2 receives a TA command <NUM>. Similar to the RTT exchange <NUM> of <FIG>, this causes a delay of Δ in the transmission of SL-PRS <NUM>-<NUM> by UE2. Thus, rather than transmitting the SL-PRS <NUM>-<NUM> at time T2, UE2 transmits an SL-PRS <NUM>-<NUM> at time T2 + Δ, and UE1 receives SL PRS <NUM>-<NUM> at TOA2 + Δ. (Again, in some instances Δ could be a negative value resulting in an earlier transmission. ) More generally, for TDOA-based positioning, such as TDOA-based measurement <NUM>, applying a TA cannot only impact the transmission time of a single subsequent SL-PRS, but may impact all subsequent occasion times/repetitions of an SL-PRS. Similar to RTT-based positioning, this can cause inaccuracies in the TDOA-based measurement and ultimately in the position estimate a UE.

Embodiments address these and other issues by allowing for a TA command for an anchor UE to be postponed or omitted until after the anchor UE conducts an SL-PRS positioning session with a target UE. Alternatively, embodiments may allow an anchor UE to report TA adjustments made during an SL-PRS positioning session to a target UE or a location server to allow the target UE or location server to account for such TA adjustments when determining the position of the target UE. A description of an embodiment is provided hereinafter with regard to <FIG>.

<FIG> is a flow diagram of a method <NUM> of TA handling for SL-assisted positioning of a first UE, according to an embodiment. Means for performing the functionality illustrated in one or more of the blocks shown in <FIG> may be performed by hardware and/or software components of a UE (e.g., an anchor UE <NUM> of <FIG>) or location server (e.g., location server <NUM> of <FIG> or LMF <NUM> of <FIG>). Example components of a UE are illustrated in <FIG>, and example components of a computer server are illustrated in <FIG>, both of which are described in more detail below.

The method <NUM> can begin with the functionality at block <NUM>, which comprises determining the first UE is configured to transmit an SL-PRS to a second UE to perform the SL-assisted positioning. This determination can be made, for example, by the first UE itself, based on an SL-PRS configuration it receives from a location server or TRP to engage in an SL-PRS positioning session with the second UE (e.g., a target UE <NUM>). Alternatively, this determination may be made by the location server, upon configuring the first UE. As previously noted, SL-PRS can be used to make RTT and/or TDOA measurements with which the position of the second UE may be estimated.

Means for performing the functionality at block <NUM> by a UE may comprise, for example, a bus <NUM>, processing unit(s) <NUM>, digital signal processor (DSP) <NUM>, wireless communication interface <NUM>, memory <NUM>, and/or other components of a UE as illustrated in <FIG> and described below. Means for performing the functionality at block <NUM> by a location server may comprise, for example, a bus <NUM>, processing unit(s) <NUM>, working memory <NUM>, wireless communication interface <NUM>, and/or other components of a computer system as illustrated in <FIG> and described below.

At block <NUM>, the functionality comprises determining a length of time for a guard period based on a configuration of the first UE for transmitting the SL-PRS, wherein the guard period comprises a period of time during which the SL-PRS is transmitted by the first UE. More specifically, a guard period may be defined as a period of time related to SL-assisted positioning of a target UE (e.g., the second UE) during which, if a TA adjustment is applied, may degrade the accuracy of any SL-PRS-based measurements. It may include not only a window of time during which the SL-PRS is transmitted (which may include a series of repeated SL-PRS resources, as described with regard to the TDOA-based measurement <NUM> of <FIG>) but may also include additional time before and/or afterward to account for processing time, timer adjustment buffer, etc. According to some embodiments, the guard period may be selected from a table of enumerated values (e.g., <NUM>, <NUM>, <NUM>, <NUM>, etc.) where, for example, the smallest value that provides sufficient time for the positioning session and any additional time before and/or afterward. Thus, for example, if SL-PRS for a TDOA-based measurement is transmitted over the course of <NUM> and <NUM> of additional time is needed for processing, timer adjustment buffer, etc., then a <NUM> guard period could be selected as the length of the guard period if it is among the enumerated values for guard period lengths. Depending on desired functionality, the guard period could be defined in terms of a number of slots, symbols, and/or subframes of an orthogonal frequency-division multiplexing (OFDM) communication scheme (such as the OFDM scheme implemented by LTE and <NUM>), and/or may simply be defined in terms of length of time.

Means for performing the functionality at block <NUM> by a UE may comprise, for example, a bus <NUM>, processing unit(s) <NUM>, digital signal processor (DSP) <NUM>, memory <NUM>, and/or other components of a UE as illustrated in <FIG> and described below. Means for performing the functionality at block <NUM> by a location server may comprise, for example, a bus <NUM>, processing unit(s) <NUM>, working memory <NUM>, and/or other components of a computer system as illustrated in <FIG> and described below.

The functionality at block <NUM> comprises sending, to a serving TRP of the first UE, a message indicating the guard period and comprising a TA-related request, wherein the TA-related request includes a request to postpone applying a TA command received by the first UE until after the guard period, or a request for the serving TRP not to send a TA command to the first UE during the guard period. These two different types of requests are reflective of two different types of scenarios.

In a first scenario, the first UE receives a TA command from its serving TRP before or during an SL-PRS positioning session that is to be applied during the SL-PRS positioning session. According to some embodiments, therefore, the functionality of method <NUM> may be in response to a TA command received by the first UE during the SL-PRS positioning session. As such, any resulting TA adjustment from applying the TA command may interfere with the timing of the transmission of the SL-PRS. Accordingly, in such instances, the first UE can send the serving TRP a request to postpone the application of the TA command until after the guard period. In this first scenario, the TA-related request may therefore comprise the request to postpone applying the TA command received by the first UE until after the guard period, and the message is sent by the first UE, during a SL-PRS positioning session during which the SL-PRS is transmitted by the first UE to the second UE. Because the SL-PRS positioning session may be partially complete, the determination of the guard period may be impacted. As such, the determining the length of time for the guard period (the functionality at block <NUM>) may further be based on her remaining amount of time in the SL-PRS positioning session.

The way in which the message is sent in this first scenario may vary, depending on desired functionality. According to some embodiments, for example, sending the message comprises including the message in UCI (Uplink Control Information), a Radio Resource Control (RRC) message, or a Medium Access Control (MAC) Control Element (CE), or any combination thereof.

In this first scenario, the method <NUM> may include additional steps if postponement is granted. For example, according to some embodiments, the method <NUM> may further comprise receiving, at the first UE, an indication from the serving TRP of an acceptance of the TA-related request and postponing the applying of the TA command received by the first UE until after the guard period. As described in more detail below, the serving TRP may grant or deny the postponement based on an applicable TA priority condition. That is, if the serving TRP determines the TA command should be applied to help ensure a high-priority process is executed smoothly, the serving TRP can deny the request. If the request is denied, the first UE can apply the TA command. As described in further detail below, according to some embodiments, the first UE may provide a network node (e.g., the second UE or the location server) with information regarding the TA adjustment to allow the network node to account for the adjustment when determining the location of the second UE.

In a second scenario, the TA-related request comprises the request for the serving TRP not to send the TA command to the first UE during the guard period and the message is sent by a location server or the first UE prior to an SL-PRS positioning session during which the SL-PRS is transmitted by the first UE to the second UE. In this scenario, the request can include a starting time and duration of the guard period. Again, the first UE can communicate this information to the serving TRP using UCI, and RRC message, a MAC-CE message, or the like. The location server can communicate this information to the serving TRP via NRPPa or a similar communication link.

The way in which the serving TRP processes the request can vary, depending on desired functionality. According to some embodiments, the serving TRP may provide an acknowledgment (or ACK) response to the message, confirming that the TA-related request is granted. And the first UE will not receive a TA command, or a previously-received TA command, can be postponed accordingly. On the other hand, the serving TRP may reject the request with a negative acknowledgment (or NACK) response to the message. In the case of a rejection of a request to postpone a previously-received TA command, the first UE would apply the TA command without postponement. In the case of a rejection of a request not to receive a TA command during the guard period, the first UE or location server would be on notice that a TA command could be received during the guard. That is, the serving TRP may or may not issue a TA command during the guard period; there may be no guarantees one way or the other. Accordingly, according some embodiments of the method <NUM> may further comprise receiving, at the first UE, a response to the message from the serving TRP, wherein the response is indicative of a rejection of the TA-related request. These embodiments may further comprise receiving, at the first UE, a TA command from the serving TRP during the guard period and applying the TA command during the guard period.

Embodiments may respond to the application of a TA command during an SL-PRS positioning session in a variety of ways, depending on desired functionality. According to some embodiments, the first UE may simply cancel the SL-PRS positioning session. Alternatively, embodiments may account for a TA adjustment made from the application of the TA command. In particular, in cases where a serving TRP rejects a TA-related request (e.g., sent using the method <NUM>) and/or as feature that may be independent of a TA-related request, the first UE may track and record its own time adjustment (e.g., the value of Δ in <FIG> and/or <NUM>). This information can be used to correct the PRS measurements.

The type of information the first UE can track and report may vary. For example, according to some embodiments, the first UE can determine which SL-PRS occasions are impacted by the TA adjustment and send an indication of the impacted occasions (e.g., using a PRS resource ID and occasion times), as well as how they were impacted (e.g., the value of Δ).

Embodiments may account for different types of TA adjustments. That is, TA commands may result in a single-step adjustment in which all SL-PRS occasions following the adjustment are impacted by the same amount. That is, the value of Δ is the same for all occasions. Alternatively, some adjustments may be gradual over time, increasing until the full adjustment is reached. In other words, the value of Δ gradually increases to a desired value, which may result in a different value of Δ for different SL-PRS occasions. As such, according to some embodiments, the first UE may indicate, in the report, how different occasions are impacted differently.

The network node to which of the first UE provides the report may vary, depending on the circumstances. For example, for UE-based positioning in which the second UE (the target UE) determines its own position based on SL-PRS measurements (e.g., RTT-based or OTDOA-based measurements of SL-PRS), the first UE may provide the report to the second UE. This can be sent directly to the second UE using the SL interface (e.g., SL interface <NUM> of <FIG>). In these instances, the second UE can use the information in the reports to account for the TA adjustment in estimating its position. The TA adjustment may be accounted for, for example, by using the value of the adjustment (Δ) to correct the PRS measurement or by determining a level of uncertainty of the PRS measurement based on the value of the adjustment.

Additionally or alternatively, for UE-assisted positioning in which the first and/or second UEs provide information (e.g., as assistance data or a PRS measurement report) to a location server to determine the estimated position of the second UE, the first UE can provide a report to the location server. This can be done via LPP, for example, using a Uu interface (e.g., Uu interface <NUM> of <FIG>). Alternatively, this can be done indirectly via the second UE, in which case the first UE would provide the report to the second UE via an SL interface, and the second UE would relay the report to the location server via a Uu interface. (In this case, the second UE may relay positioning-related information from other UEs, which may be used to make similar SL-PRS measurements. ) In either case, the location server can use the information in the report to account for a TA adjustment when determining the estimated position of the second UE.

Returning to <FIG>, the method <NUM> may therefore provide this functionality in instances in which the TA-related request at block <NUM> is rejected by the serving TRP. Alternative embodiments of the method <NUM> may therefore comprise receiving, at the first UE, a response to the message from the serving TRP, where the response is indicative of a rejection of the TA-related request, receiving, at the first UE, a TA command from the serving TRP during the guard period, and applying the TA command during the guard period. Embodiments may further comprise sending, from the first UE, a report to a network node, wherein the report comprises a time adjustment of a transmission time of the SL-PRS based on applying the TA command during the guard period, and a PRS resource identifier (ID) of the SL-PRS.

As noted, the serving TRP may use an applicable TA priority condition when determining whether to grant or reject the TA-related request from the location server or first UE. This process is described in further detail with regard to <FIG>.

<FIG> is a flow diagram of a method <NUM> of TA handling for SL-assisted positioning of a first UE, according to an embodiment, which can be performed by the serving TRP of the first UE. As such, means for performing the functionality illustrated in one or more of the blocks shown in <FIG> may be performed by hardware and/or software components of a TRP. Example components of a TRP are illustrated in <FIG>, which are described in more detail below.

The method <NUM> can begin with the functionality at block <NUM>, which comprises receiving, at a serving TRP of the first UE, a message from a network node, the message indicating a guard period and comprising a TA-related request, wherein: the guard period comprises a period of time during which an SL-PRS is transmitted by the first UE to a second UE. The TA-related request comprises: a request to postpone applying a TA command received by the first UE until after the guard period, or a request for the serving TRP not to send a TA command to the first UE during the guard period. Here, the functionality at block <NUM> may comprise the functionality of the serving TRP when receiving the information sent in block <NUM> of <FIG>. As such, the guard period, TA-related request, and other aspects may correspond to those previously described. Moreover, as noted, the request may come from different sources depending on circumstances. Thus, according to some embodiments, the network node comprises the first UE or a location server.

Means for performing the functionality at block <NUM> by a TRP may comprise, for example, a bus <NUM>, processing unit(s) <NUM>, digital signal processor (DSP) <NUM>, wireless communication interface <NUM>, memory <NUM>, network interface <NUM>, and/or other components of a UE as illustrated in <FIG> and described below.

At block <NUM>, the functionality comprises determining a response to the message based on an applicable TA priority condition. As discussed previously, the serving TRP can choose whether to grant or deny/reject a request based on whether or not other functions may be impacted by a delay in applying a TA command by the first UE. In implementation, priority rules for granting or rejecting a TA-related request related to SL-PRS positioning of a UE in view of TA priority conditions may be included in applicable communication standards, allowing the serving TRP to implement these priority rules upon receiving a TA-related request.

A TA priority condition comprises a condition that could be impacted by granting the TA-related request. This can include, for example, high-priority conditions such as handover of the first UE between cells (e.g., designating a different serving TRP), high-priority communications (e.g., mission-critical or Ultra-Reliable Low-Latency Communication (URLLC) communications). According to some embodiments, therefore, if the applicable TA priority condition includes either (or both) of these conditions (the first UE being engaged in a handover procedure or the first UE engaged in high-priority medications), then the serving TRP may reject the TA-related request. Otherwise, the serving TRP may accept the TA-related request.

Means for performing the functionality at block <NUM> by a TRP may comprise, for example, a bus <NUM>, processing unit(s) <NUM>, digital signal processor (DSP) <NUM>, memory <NUM>, and/or other components of a UE as illustrated in <FIG> and described below.

At block <NUM>, the functionality comprises sending the response to the network node. As previously noted, the response may be either indicative of a rejection of TA-related request, or indicative of an acceptance of TA-related request TA-related request. Moreover, the response may be in the form of an ACK or NACK response to the message received at block <NUM>.

<FIG> illustrates an embodiment of a UE <NUM>, which can be utilized as described herein above (e.g., in association with <FIG>) and may correspond with UE <NUM>, target UE <NUM>, anchor UE <NUM>, UE1 and/or UE2. For example, the UE <NUM> can perform one or more of the functions of the method shown in <FIG>. It should be noted that <FIG> is meant only to provide a generalized illustration of various components, any or all of which may be utilized as appropriate. It can be noted that, in some instances, components illustrated by <FIG> can be localized to a single physical device and/or distributed among various networked devices, which may be disposed at different physical locations. Furthermore, as previously noted, the functionality of the UE discussed in the previously described embodiments may be executed by one or more of the hardware and/or software components illustrated in <FIG>.

The UE <NUM> is shown comprising hardware elements that can be electrically coupled via a bus <NUM> (or may otherwise be in communication, as appropriate). The hardware elements may include a processing unit(s) <NUM> which can include without limitation one or more general-purpose processors, one or more special-purpose processors (such as DSP chips, graphics acceleration processors, application specific integrated circuits (ASICs), and/or the like), and/or other processing structures or means. As shown in <FIG>, some embodiments may have a separate DSP <NUM>, depending on desired functionality. Location determination and/or other determinations based on wireless communication may be provided in the processing unit(s) <NUM> and/or wireless communication interface <NUM> (discussed below). The UE <NUM> also can include one or more input devices <NUM>, which can include without limitation one or more keyboards, touch screens, touch pads, microphones, buttons, dials, switches, and/or the like; and one or more output devices <NUM>, which can include without limitation one or more displays (e.g., touch screens), light emitting diodes (LEDs), speakers, and/or the like.

The UE <NUM> may also include a wireless communication interface <NUM>, which may comprise without limitation a modem, a network card, an infrared communication device, a wireless communication device, and/or a chipset (such as a Bluetooth® device, an IEEE <NUM> device, an IEEE <NUM>. <NUM> device, a Wi-Fi device, a WiMAX device, a WAN device, and/or various cellular devices, etc.), and/or the like, which may enable the UE <NUM> to communicate with other devices as described in the embodiments above. The wireless communication interface <NUM> may permit data and signaling to be communicated (e.g., transmitted and received) with TRPs of a network, for example, via eNBs, gNBs, ng-eNBs, access points, various base stations and/or other access node types, and/or other network components, computer systems, and/or any other electronic devices communicatively coupled with TRPs, as described herein. The communication can be carried out via one or more wireless communication antenna(s) <NUM> that send and/or receive wireless signals <NUM>. According to some embodiments, the wireless communication antenna(s) <NUM> may comprise a plurality of discrete antennas, antenna arrays, or any combination thereof. The antenna(s) <NUM> may be capable of transmitting and receiving wireless signals using beams (e.g., Tx beams and Rx beams). Beam formation may be performed using digital and/or analog beam formation techniques, with respective digital and/or analog circuitry. The wireless communication interface <NUM> may include such circuitry.

Depending on desired functionality, the wireless communication interface <NUM> may comprise a separate receiver and transmitter, or any combination of transceivers, transmitters, and/or receivers to communicate with base stations (e.g., ng-eNBs and gNBs) and other terrestrial transceivers, such as wireless devices and access points. The UE <NUM> may communicate with different data networks that may comprise various network types. For example, a Wireless Wide Area Network (WWAN) may be a CDMA network, a Time Division Multiple Access (TDMA) network, a Frequency Division Multiple Access (FDMA) network, an Orthogonal Frequency Division Multiple Access (OFDMA) network, a Single-Carrier Frequency Division Multiple Access (SC-FDMA) network, a WiMAX (IEEE <NUM>) network, and so on. A CDMA network may implement one or more RATs such as CDMA2000, WCDMA, and so on. CDMA2000 includes IS-<NUM>, IS-<NUM> and/or IS-<NUM> standards. A TDMA network may implement GSM, Digital Advanced Mobile Phone System (D-AMPS), or some other RAT. An OFDMA network may employ LTE, LTE Advanced, <NUM> NR, and so on. <NUM> NR, LTE, LTE Advanced, GSM, and WCDMA are described in documents from 3GPP. Cdma2000 is described in documents from a consortium named "3rd Generation Partnership Project X3" (3GPP2). 3GPP and 3GPP2 documents are publicly available. A wireless local area network (WLAN) may also be an IEEE <NUM>. 11x network, and a wireless personal area network (WPAN) may be a Bluetooth network, an IEEE <NUM>. 15x, or some other type of network. The techniques described herein may also be used for any combination of WWAN, WLAN and/or WPAN.

The UE <NUM> can further include sensor(s) <NUM>. Sensors <NUM> may comprise, without limitation, one or more inertial sensors and/or other sensors (e.g., accelerometer(s), gyroscope(s), camera(s), magnetometer(s), altimeter(s), microphone(s), proximity sensor(s), light sensor(s), barometer(s), and the like), some of which may be used to obtain position-related measurements and/or other information.

Embodiments of the UE <NUM> may also include a Global Navigation Satellite System (GNSS) receiver <NUM> capable of receiving signals <NUM> from one or more GNSS satellites using an antenna <NUM> (which could be the same as antenna <NUM>). Positioning based on GNSS signal measurement can be utilized to complement and/or incorporate the techniques described herein. The GNSS receiver <NUM> can extract a position of the UE <NUM>, using conventional techniques, from GNSS satellites <NUM> of a GNSS system, such as Global Positioning System (GPS), Galileo, GLONASS, Quasi-Zenith Satellite System (QZSS) over Japan, IRNSS over India, BeiDou Navigation Satellite System (BDS) over China, and/or the like. Moreover, the GNSS receiver <NUM> can be used with various augmentation systems (e.g., a Satellite Based Augmentation System (SBAS)) that may be associated with or otherwise enabled for use with one or more global and/or regional navigation satellite systems, such as, e.g., Wide Area Augmentation System (WAAS), European Geostationary Navigation Overlay Service (EGNOS), Multi-functional Satellite Augmentation System (MSAS), and Geo Augmented Navigation system (GAGAN), and/or the like.

It can be noted that, although GNSS receiver <NUM> is illustrated in <FIG> as a distinct component, embodiments are not so limited. As used herein, the term "GNSS receiver" may comprise hardware and/or software components configured to obtain GNSS measurements (measurements from GNSS satellites). In some embodiments, therefore, the GNSS receiver may comprise a measurement engine executed (as software) by one or more processing units, such as processing unit(s) <NUM>, DSP <NUM>, and/or a processing unit within the wireless communication interface <NUM> (e.g., in a modem). A GNSS receiver may optionally also include a positioning engine, which can use GNSS measurements from the measurement engine to determine a position of the GNSS receiver using an Extended Kalman Filter (EKF), Weighted Least Squares (WLS), a hatch filter, particle filter, or the like. The positioning engine may also be executed by one or more processing units, such as processing unit(s) <NUM> or DSP <NUM>.

The UE <NUM> may further include and/or be in communication with a memory <NUM>. The memory <NUM> can include, without limitation, local and/or network accessible storage, a disk drive, a drive array, an optical storage device, a solid-state storage device, such as a random access memory (RAM), and/or a read-only memory (ROM), which can be programmable, flash-updateable, and/or the like. Such storage devices may be configured to implement any appropriate data stores, including without limitation, various file systems, database structures, and/or the like.

The memory <NUM> of the UE <NUM> also can comprise software elements (not shown in <FIG>), including an operating system, device drivers, executable libraries, and/or other code, such as one or more application programs, which may comprise computer programs provided by various embodiments, and/or may be designed to implement methods, and/or configure systems, provided by other embodiments, as described herein. Merely by way of example, one or more procedures described with respect to the method(s) discussed above may be implemented as code and/or instructions in memory <NUM> that are executable by the UE <NUM> (and/or processing unit(s) <NUM> or DSP <NUM> within UE <NUM>). In an aspect, then such code and/or instructions can be used to configure and/or adapt a general-purpose computer (or other device) to perform one or more operations in accordance with the described methods.

<FIG> illustrates an embodiment of a TRP <NUM>, which can be utilized as described herein above (e.g., in association with <FIG>) and may correspond with base station <NUM>, gNB <NUM>, a ng-eNB <NUM>, TRP <NUM>, TRP <NUM>, and/or TRP <NUM>. The TRP <NUM> may be configured to perform one or more of the operations illustrated in the method <NUM> of <FIG> It should be noted that <FIG> is meant only to provide a generalized illustration of various components, any or all of which may be utilized as appropriate.

The TRP <NUM> is shown comprising hardware elements that can be electrically coupled via a bus <NUM> (or may otherwise be in communication, as appropriate). The hardware elements may include a processing unit(s) <NUM> which can include without limitation one or more general-purpose processors, one or more special-purpose processors (such as DSP chips, graphics acceleration processors, ASICs, and/or the like), and/or other processing structure or means. As shown in <FIG>, some embodiments may have a separate DSP <NUM>, depending on desired functionality. Location determination and/or other determinations based on wireless communication may be provided in the processing unit(s) <NUM> and/or wireless communication interface <NUM> (discussed below), according to some embodiments. The TRP <NUM> also can include one or more input devices, which can include without limitation a keyboard, display, mouse, microphone, button(s), dial(s), switch(es), and/or the like; and one or more output devices, which can include without limitation a display, light emitting diode (LED), speakers, and/or the like.

The TRP <NUM> might also include a wireless communication interface <NUM>, which may comprise without limitation a modem, a network card, an infrared communication device, a wireless communication device, and/or a chipset (such as a Bluetooth® device, an IEEE <NUM> device, an IEEE <NUM>. <NUM> device, a Wi-Fi device, a WiMAX device, cellular communication facilities, etc.), and/or the like, which may enable the TRP <NUM> to communicate as described herein. The wireless communication interface <NUM> may permit data and signaling to be communicated (e.g., transmitted and received) to UEs, other base stations/TRPs (e.g., eNBs, gNBs, and ng-eNBs), and/or other network components, computer systems, and/or any other electronic devices described herein. The communication can be carried out via one or more wireless communication antenna(s) <NUM> that send and/or receive wireless signals <NUM>.

The TRP <NUM> may also include a network interface <NUM>, which can include support of wireline communication technologies. The network interface <NUM> may include a modem, network card, chipset, and/or the like. The network interface <NUM> may include one or more input and/or output communication interfaces to permit data to be exchanged with a network, communication network servers, computer systems, and/or any other electronic devices described herein.

In many embodiments, the TRP <NUM> may further comprise a memory <NUM>. The memory <NUM> can include, without limitation, local and/or network accessible storage, a disk drive, a drive array, an optical storage device, a solid-state storage device, such as a RAM, and/or a ROM, which can be programmable, flash-updateable, and/or the like. Such storage devices may be configured to implement any appropriate data stores, including without limitation, various file systems, database structures, and/or the like.

The memory <NUM> of the TRP <NUM> also may comprise software elements (not shown in <FIG>), including an operating system, device drivers, executable libraries, and/or other code, such as one or more application programs, which may comprise computer programs provided by various embodiments, and/or may be designed to implement methods, and/or configure systems, provided by other embodiments, as described herein. Merely by way of example, one or more procedures described with respect to the method(s) discussed above may be implemented as code and/or instructions in memory <NUM> that are executable by the TRP <NUM> (and/or processing unit(s) <NUM> or DSP <NUM> within TRP <NUM>). In an aspect, then such code and/or instructions can be used to configure and/or adapt a general-purpose computer (or other device) to perform one or more operations in accordance with the described methods.

<FIG> is a block diagram of an embodiment of a computer system <NUM>, which may be used, in whole or in part, to provide the functions of a server or other network node described herein with regard to <FIG> and may correspond with location server <NUM>, external client <NUM>, LMF <NUM>, and/or other network-connected devices described herein. It should be noted that <FIG> is meant only to provide a generalized illustration of various components, any or all of which may be utilized as appropriate. <FIG>, therefore, broadly illustrates how individual system elements may be implemented in a relatively separated or relatively more integrated manner. In addition, it can be noted that components illustrated by <FIG> can be localized to a single device and/or distributed among various networked devices, which may be disposed at different geographical locations.

The computer system <NUM> is shown comprising hardware elements that can be electrically coupled via a bus <NUM> (or may otherwise be in communication, as appropriate). The hardware elements may include processing unit(s) <NUM>, which may comprise without limitation one or more general-purpose processors, one or more special-purpose processors (such as digital signal processing chips, graphics acceleration processors, and/or the like), and/or other processing structure, which can be configured to perform one or more of the methods described herein. The computer system <NUM> also may comprise one or more input devices <NUM>, which may comprise without limitation a mouse, a keyboard, a camera, a microphone, and/or the like; and one or more output devices <NUM>, which may comprise without limitation a display device, a printer, and/or the like.

The computer system <NUM> may further include (and/or be in communication with) one or more non-transitory storage devices <NUM>, which can comprise, without limitation, local and/or network accessible storage, and/or may comprise, without limitation, a disk drive, a drive array, an optical storage device, a solid-state storage device, such as a RAM and/or ROM, which can be programmable, flash-updateable, and/or the like. Such storage devices may be configured to implement any appropriate data stores, including without limitation, various file systems, database structures, and/or the like. Such data stores may include database(s) and/or other data structures used store and administer messages and/or other information to be sent to one or more devices via hubs, as described herein.

The computer system <NUM> may also include a communications subsystem <NUM>, which may comprise wireless communication technologies managed and controlled by a wireless communication interface <NUM>, as well as wired technologies (such as Ethernet, coaxial communications, universal serial bus (USB), and the like). The wireless communication interface <NUM> may send and receive wireless signals <NUM> (e.g., signals according to <NUM> NR or LTE) via wireless antenna(s) <NUM>. Thus the communications subsystem <NUM> may comprise a modem, a network card (wireless or wired), an infrared communication device, a wireless communication device, and/or a chipset, and/or the like, which may enable the computer system <NUM> to communicate on any or all of the communication networks described herein to any device on the respective network, including a User Equipment (UE), base stations and/or other TRPs, and/or any other electronic devices described herein. Hence, the communications subsystem <NUM> may be used to receive and send data as described in the embodiments herein.

In many embodiments, the computer system <NUM> will further comprise a working memory <NUM>, which may comprise a RAM or ROM device, as described above. Software elements, shown as being located within the working memory <NUM>, may comprise an operating system <NUM>, device drivers, executable libraries, and/or other code, such as one or more applications <NUM>, which may comprise computer programs provided by various embodiments, and/or may be designed to implement methods, and/or configure systems, provided by other embodiments, as described herein. Merely by way of example, one or more procedures described with respect to the method(s) discussed above might be implemented as code and/or instructions executable by a computer (and/or a processing unit within a computer); in an aspect, then, such code and/or instructions can be used to configure and/or adapt a general purpose computer (or other device) to perform one or more operations in accordance with the described methods.

A set of these instructions and/or code might be stored on a non-transitory computer-readable storage medium, such as the storage device(s) <NUM> described above. In some cases, the storage medium might be incorporated within a computer system, such as computer system <NUM>. In other embodiments, the storage medium might be separate from a computer system (e.g., a removable medium, such as an optical disc), and/or provided in an installation package, such that the storage medium can be used to program, configure, and/or adapt a general purpose computer with the instructions/code stored thereon. These instructions might take the form of executable code, which is executable by the computer system <NUM> and/or might take the form of source and/or installable code, which, upon compilation and/or installation on the computer system <NUM> (e.g., using any of a variety of generally available compilers, installation programs, compression/decompression utilities, etc.), then takes the form of executable code.

For example, customized hardware might also be used and/or particular elements might be implemented in hardware, software (including portable software, such as applets, etc.), or both.

With reference to the appended figures, components that can include memory can include non-transitory machine-readable media. The term "machine-readable medium" and "computer-readable medium" as used herein, refer to any storage medium that participates in providing data that causes a machine to operate in a specific fashion. In embodiments provided hereinabove, various machine-readable media might be involved in providing instructions/code to processing units and/or other device(s) for execution. Additionally or alternatively, the machine-readable media might be used to store and/or carry such instructions/code. In many implementations, a computer-readable medium is a physical and/or tangible storage medium. Such a medium may take many forms, including but not limited to, non-volatile media and volatile media. Common forms of computer-readable media include, for example, magnetic and/or optical media, any other physical medium with patterns of holes, a RAM, a programmable ROM (PROM), erasable PROM (EPROM), a FLASH-EPROM, any other memory chip or cartridge, or any other medium from which a computer can read instructions and/or code.

The methods, systems, and devices discussed herein are examples. Various embodiments may omit, substitute, or add various procedures or components as appropriate. For instance, features described with respect to certain embodiments may be combined in various other embodiments. Different aspects and elements of the embodiments may be combined in a similar manner. The various components of the figures provided herein can be embodied in hardware and/or software. Also, technology evolves and, thus many of the elements are examples that do not limit the scope of the disclosure to those specific examples.

It has proven convenient at times, principally for reasons of common usage, to refer to such signals as bits, information, values, elements, symbols, characters, variables, terms, numbers, numerals, or the like. It should be understood, however, that all of these or similar terms are to be associated with appropriate physical quantities and are merely convenient labels. Unless specifically stated otherwise, as is apparent from the discussion above, it is appreciated that throughout this Specification discussion utilizing terms such as "processing," "computing," "calculating," "determining," "ascertaining," "identifying," "associating," "measuring," "performing," or the like refer to actions or processes of a specific apparatus, such as a special purpose computer or a similar special purpose electronic computing device. In the context of this Specification, therefore, a special purpose computer or a similar special purpose electronic computing device is capable of manipulating or transforming signals, typically represented as physical electronic, electrical, or magnetic quantities within memories, registers, or other information storage devices, transmission devices, or display devices of the special purpose computer or similar special purpose electronic computing device.

Terms, "and" and "or" as used herein, may include a variety of meanings that also is expected to depend, at least in part, upon the context in which such terms are used. Typically, "or" if used to associate a list, such as A, B, or C, is intended to mean A, B, and C, here used in the inclusive sense, as well as A, B, or C, here used in the exclusive sense. In addition, the term "one or more" as used herein may be used to describe any feature, structure, or characteristic in the singular or may be used to describe some combination of features, structures, or characteristics. However, it should be noted that this is merely an illustrative example and claimed subject matter is not limited to this example. Furthermore, the term "at least one of" if used to associate a list, such as A, B, or C, can be interpreted to mean any combination of A, B, and/or C, such as A, AB, AA, AAB, AABBCCC, etc..

Claim 1:
A method (<NUM>) of Timing Advance, TA, handling for sidelink ,SL,-assisted positioning of a first User Equipment, UE, the method comprising:
determining (<NUM>) the first UE is configured to transmit an SL Positioning Reference Signal, SL-PRS, to a second UE to perform the SL-assisted positioning;
determining (<NUM>) a length of time for a guard period based on a configuration of the first UE for transmitting the SL-PRS, wherein the guard period comprises a period of time during which the SL-PRS is transmitted by the first UE; and
sending, to a serving Transmission Reception Point, TRP, of the first UE, a message indicating the guard period and comprising a TA-related request, wherein the TA-related request includes:
a request to postpone applying a TA command received by the first UE until after the guard period, or
a request for the serving TRP not to send a TA command to the first UE during the guard period.