PATENT DOCUMENT

Publication Number: US-12047320-B2
Application Number: US-202117444295-A
Country: US
Kind Code: B2

Title: Network operations related to receiving positioning SRS transmissions

Abstract:
A base station serves as a positioning node for locating a user equipment (UE). The base station receives information from a network component indicating the UE is transmitting positioning sounding reference signals (SRS), monitors for the positioning SRS based on, at least, the information and when positioning SRS are received from the UE, transmits SRS information to the network.

Claims:
What is claimed: 
     
       1. A method, comprising:
 at a base station serving as a positioning node for locating a user equipment (UE):
 receiving information from a network component indicating the UE is transmitting positioning sounding reference signals (SRS), wherein the information comprises UE configuration information that includes discontinuous reception (DRX) timing information for indicating a DRX active time and a DRX inactive time in a DRX cycle of the UE, wherein periodic and semi-persistent positioning SRS are not transmitted by the UE during DRX inactive time and aperiodic positioning SRS are transmitted by the UE during both the DRX active time and the DRX inactive time; 
 monitoring for the positioning SRS based on, at least, the information; and 
 when positioning SRS are received from the UE, transmitting SRS information to the network. 
 
 
     
     
       2. The method of  claim 1 , wherein the UE configuration information relates to time periods when the UE transmits a positioning SRS, the method further comprising:
 determining a monitoring period for monitoring for the positioning SRS based on the UE configuration information. 
 
     
     
       3. The method of  claim 1 , wherein the DRX timing information includes at least one of a drx-LongCycleStartOffset, a drx-ShortCycle, a drx-ShortCycleTimer, a drx-onDurationTimer or a reference time for the DRX cycle. 
     
     
       4. The method of  claim 1 , wherein the network component comprises a location management function (LMF) of the network. 
     
     
       5. The method of  claim 2 , wherein the UE configuration information includes measurement gap (MG) timing information for the UE. 
     
     
       6. The method of  claim 5 , wherein the UE configuration information comprises the UE does not transmit positioning SRS during MGs. 
     
     
       7. The method of  claim 5 , wherein the MG timing information includes one of a measurement gap repetition period, a measurement gap length, a measurement gap timing advance or a reference time for the MG. 
     
     
       8. The method of  claim 5 , wherein the MG timing information includes an MG type being a per-UE MG type, wherein the UE does not transmit positioning SRS when the MG type is the per-UE MG type. 
     
     
       9. The method of  claim 5 , wherein the MG timing information includes an MG type being a per-frequency range (FR) type, wherein the UE transmits positioning SRS in FR2 when there is an FR1 MG and the UE transmits positioning SRS in FR1 when there is an FR2 MG. 
     
     
       10. A base station serving as a positioning node for locating a user equipment (UE), comprising:
 one or more processors configured to:
 receive information from a network component indicating the UE is transmitting positioning sounding reference signals (SRS), wherein the information comprises UE configuration information that includes discontinuous reception (DRX) timing information for indicating a DRX active time and a DRX inactive time in a DRX cycle of the UE, wherein periodic and semi-persistent positioning SRS are not transmitted by the UE during DRX inactive time and aperiodic positioning SRS are transmitted by the UE during both the DRX active time and the DRX inactive time; 
 monitor for the positioning SRS based on, at least, the information; and 
 when positioning SRS are received from the UE, transmit SRS information to the network. 
 
 
     
     
       11. The base station of  claim 10 , wherein the UE configuration information relates to time periods when the UE transmits a positioning SRS, the one or more processors further configured to:
 determine a monitoring period for monitoring for the positioning SRS based on the UE configuration information. 
 
     
     
       12. The base station of  claim 10 , wherein the DRX timing information includes at least one of a drx-LongCycleStartOffset, a drx-ShortCycle, a drx-ShortCycleTimer, a drx-onDurationTimer or a reference time for the DRX cycle. 
     
     
       13. The base station of  claim 11 , wherein the UE configuration information includes measurement gap (MG) timing information for the UE. 
     
     
       14. The base station of  claim 13 , wherein the MG timing information includes one of a measurement gap repetition period, a measurement gap length, a measurement gap timing advance or a reference time for the MG. 
     
     
       15. The base station of  claim 13 , wherein the MG timing information includes a MG type, the MG type being one of per-UE or per-frequency range (FR). 
     
     
       16. The base station of  claim 15 , wherein the UE supports the per-FR MG type, wherein an independent gap pattern is defined for FR1 and FR2, respectively, and the UE configuration information includes MG timing information relating to FR1 or FR2. 
     
     
       17. A non-transitory computer readable storage medium comprising a set of instructions that when executed by a processor causes the processor to perform operations, comprising:
 receiving information from a network component of a network indicating a user equipment (UE) is transmitting positioning sounding reference signals (SRS), wherein the information comprises UE configuration information that includes discontinuous reception (DRX) timing information for indicating a DRX active time and a DRX inactive time in a DRX cycle of the UE, wherein periodic and semi-persistent positioning SRS are not transmitted by the UE during DRX inactive time and aperiodic positioning SRS are transmitted by the UE during both the DRX active time and the DRX inactive time; 
 monitoring for the positioning SRS based on, at least, the information; and 
 when positioning SRS are received from the UE, transmitting SRS information to the network. 
 
     
     
       18. The non-transitory computer readable storage medium of  claim 17 , wherein the UE configuration information relates to time periods when the UE transmits a positioning SRS, the operations further comprising:
 determining a monitoring period for monitoring for the positioning SRS based on the UE configuration information. 
 
     
     
       19. A user equipment (UE), comprising:
 one or more processors configured to perform operations comprising: 
 
       receiving configuration information related to positioning sounding reference signals (SRS), wherein the configuration information further includes discontinuous reception (DRX) timing information indicating a DRX active time and a DRX inactive time in a DRX cycle of the UE, the operations further comprising:
  operating the UE in accordance with the DRX timing information, wherein the transmitting positioning SRS comprises not transmitting periodic and semi-persistent positioning SRS during the DRX inactive time and transmitting aperiodic positioning SRS during the DRX active time and the DRX inactive time; and 
 transmitting positioning SRS according to the configuration information. 
 
     
     
       20. The UE of  claim 19 , wherein the configuration information includes measurement gap (MG) timing information for the UE. 
     
     
       21. The UE of  claim 20 , wherein the operations further comprise:
 operating the UE in accordance with the MG timing information, wherein the transmitting positioning SRS comprises not transmitting during MGs. 
 
     
     
       22. The UE of  claim 20 , wherein the MG timing information includes an MG type being a per-UE MG type, wherein the operations further comprise:
 operating the UE in accordance with the MG timing information, wherein the transmitting positioning SRS comprises 
 not transmitting positioning SRS when the MG type is the per-UE MG type. 
 
     
     
       23. The UE of  claim 20 , wherein the MG timing information includes an MG type being a per-frequency range (FR) type, wherein the operations further comprise:
 operating the UE in accordance with the MG timing information, wherein the transmitting positioning SRS comprises 
 transmitting positioning SRS in FR2 when there is an FR1 MG and transmitting positioning SRS in FR1 when there is an FR2 MG.

Description:
PRIORITY/INCORPORATION BY REFERENCE 
     This application claims priority to U.S. Provisional Patent Application Ser. No. 63/061,265 filed on Aug. 5, 2020 and entitled “Network Operations Related to Receiving Positioning SRS Transmissions,” the entirety of which is incorporated herein, by reference. 
    
    
     BACKGROUND 
     A user equipment (UE) may establish a connection to at least one of a plurality of different networks or types of networks. Various positioning methods exist for the network to locate the UE. In some positioning methods, including multiple round trip time (RTT) and Uplink Time Difference of Arrival (UTDOA), a sounding reference signal (SRS) is transmitted from a target UE to each of multiple network nodes, i.e. positioning nodes, so that the uplink arrival timings of the respective SRSs at the positioning nodes may be determined, and a location of the UE determined therefrom. 
     To locate the UE, the network may request a serving node for a UE to configure the UE for the positioning SRS transmission. The network may receive the SRS configuration from the serving node and inform the positioning nodes of the SRS configuration so that the positioning nodes may monitor for the SRS from the UE. However, the network may not have precise information regarding when the UE will transmit the SRS and when the UE will not transmit the SRS. For example, the UE may not transmit periodic or semi-persistent SRS during a discontinuous reception (DRX) inactive period. Additionally, the UE may not transmit periodic, semi-persistent, or aperiodic SRS during a measurement gap (MG). If the network is not informed of the times when the UE cannot transmit the SRS then positioning node resources may be wasted if the positioning nodes monitor for the SRS during these times. 
     SUMMARY 
     Some exemplary aspects are related to a method performed by a base station serving as a positioning node for locating a user equipment (UE). The method includes receiving information from a network component indicating the UE is transmitting positioning sounding reference signals (SRS), monitoring for the positioning SRS based on, at least, the information and when positioning SRS are received from the UE, transmitting SRS information to the network. 
     Other exemplary aspects are related a base station serving as a positioning node for locating a user equipment (UE). The base station includes one or more processors that receive information from a network component indicating the UE is transmitting positioning sounding reference signals (SRS), monitor for the positioning SRS based on, at least, the information and when positioning SRS are received from the UE, transmit SRS information to the network. 
     Still further exemplary aspects are related to a computer readable storage medium having a set of instructions. When the instructions are executed by a processor, the processor performs operations. The operations include receiving information from a network component of a network indicating a user equipment (UE) is transmitting positioning sounding reference signals (SRS), monitoring for the positioning SRS based on, at least, the information and when positioning SRS are received from the UE, transmitting SRS information to the network. 
     Other exemplary aspects are related to a user equipment having one or more processors that perform operations. The operations include receiving configuration information related to positioning sounding reference signals (SRS) and transmitting positioning SRS according to the configuration information. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    shows a network arrangement according to various exemplary aspects. 
         FIG.  2    shows an exemplary UE according to various exemplary aspects. 
         FIG.  3    shows an exemplary network cell according to various exemplary aspects. 
         FIG.  4    shows a network arrangement including a UE and three gNBs utilized in a positioning determination for the UE. 
         FIG.  5    shows a method for locating a user equipment (UE). 
         FIG.  6    shows a method for preventing a positioning SRS signaling period from being aligned with a DRX inactive time for a user equipment (UE). 
     
    
    
     DETAILED DESCRIPTION 
     The exemplary aspects may be further understood with reference to the following description and the related appended drawings, wherein like elements are provided with the same reference numerals. The exemplary aspects describe network configurations for monitoring for a positioning sounding reference signal (SRS) transmission from a user equipment UE. Specifically, the exemplary aspects describe configurations for positioning nodes to monitor for a positioning SRS from a target UE during a positioning method implemented by the network for the target UE. The positioning nodes may receive information from the network relating to periods when the UE will or will not send the positioning SRS. The information may include a discontinuous reception (DRX) configuration for the UE, a measurement gap (MG) configuration for the UE, and/or other information, to be explained in detail below, that affect the periods when the UE is allowed or prevented from sending the positioning SRS. 
     The exemplary aspects are described with regard to a user equipment (UE). However, the use of a UE is provided for illustrative purposes. The exemplary aspects may be utilized with any electronic component that may establish a connection with a network and is configured with the hardware, software, and/or firmware to exchange information and data with the network. Therefore, the UE as described herein is used to represent any electronic component that is capable of providing positioning SRS to a network cell so that the network cell may perform positioning measurements for the UE. 
     The exemplary aspects are described with regard to the network being a 5G New Radio (NR) network and a base station being a next generation Node B (gNB). The 5G NR network may utilize a discontinuous reception cycle (DRX) and a measurement gap (MG) and configure connected UEs accordingly. The 5G NR network may also utilize various positioning methods for locating connected UEs. However, the use of the 5G NR network, the gNB, the DRX cycle, the MG, and the described positioning methods are provided for illustrative purposes. The exemplary aspects may apply to any type of network that utilizes similar functionalities. 
     In addition, throughout this description, a gNB may be referred to as a “serving cell.” A gNB that is acting as a serving cell is the cell to which a UE is currently connected, e.g., the UE may be in a Radio Resource Control (RRC) Connected state with the gNB and may be actively exchanging data and/or control information with the cell. A gNB may also be referred to as a “positioning gNB,” a “positioning node” or a “positioning cell.” A gNB acting as a positioning cell is a cell that is assisting in locating the UE, e.g., receiving positioning SRS signals from the UE to assist in locating the UE. A gNB may simultaneously act as a serving cell and a positioning cell with respect to a UE or may act only as a positioning cell for a UE. 
     Furthermore, throughout this description, the terms “positioning SRS” or “SRS” are used to describe the signals transmitted by the UE to allow the network to locate the UE. Those skilled in the art will understand that the SRS may also be used for other purposes in addition to location, e.g., channel estimation. Thus, the positioning SRS described herein are not limited to any specific type of SRS. 
       FIG.  1    shows an exemplary network arrangement  100  according to various exemplary aspects. The exemplary network arrangement  100  includes a user equipment (UE)  110 . Those skilled in the art will understand that the UE may be any type of electronic component that is configured to communicate via a network, e.g., mobile phones, tablet computers, smartphones, phablets, embedded devices, wearable devices, Cat-M devices, Cat-M1 devices, MTC devices, eMTC devices, other types of Internet of Things (IoT) devices, etc. It should also be understood that an actual network arrangement may include any number of UEs being used by any number of users. Thus, the example of a single UE  110  is merely provided for illustrative purposes. 
     The UE  110  may communicate directly with one or more networks. In the example of the network configuration  100 , the networks with which the UE  110  may wirelessly communicate are a 5G NR radio access network (5G NR-RAN)  120 , an LTE radio access network (LTE-RAN)  122  and a wireless local access network (WLAN)  124 . Therefore, the UE  110  may include a 5G NR chipset to communicate with the 5G NR-RAN  120 , an LTE chipset to communicate with the LTE-RAN  122  and an ISM chipset to communicate with the WLAN  124 . However, the UE  110  may also communicate with other types of networks (e.g. legacy cellular networks) and the UE  110  may also communicate with networks over a wired connection. With regard to the exemplary aspects, the UE  110  may establish a connection with the 5G NR-RAN  122 . 
     The 5G NR-RAN  120  and the LTE-RAN  122  may be portions of cellular networks that may be deployed by cellular providers (e.g., Verizon, AT&amp;T, Sprint, T-Mobile, etc.). These networks  120 ,  122  may include, for example, cells or base stations (Node Bs, eNodeBs, HeNBs, eNBS, gNBs, gNodeBs, macrocells, microcells, small cells, femtocells, etc.) that are configured to send and receive traffic from UEs that are equipped with the appropriate cellular chip set. The WLAN  124  may include any type of wireless local area network (WiFi, Hot Spot, IEEE 802.11x networks, etc.). 
     The UE  110  may connect to the 5G NR-RAN via at least one of the next generation nodeB (gNB)  120 A and/or the gNB  120 B. Reference to two gNBs  120 A,  120 B is merely for illustrative purposes. The exemplary aspects may apply to any appropriate number of gNBs. For example, three or more gNBs may be utilized as positioning gNBs for estimating positioning SRS transmitted from a target UE. The positioning gNBs may then provide their respective measurements, e.g. SRS estimations, to the network so that the network may determine a location of the target UE therefrom, to be described in further detail below. 
     In addition to the networks  120 ,  122  and  124  the network arrangement  100  also includes a cellular core network  130 , the Internet  140 , an IP Multimedia Subsystem (IMS)  150 , and a network services backbone  160 . The cellular core network  130 , e.g. the 5GC for the 5G NR network, may be considered to be the interconnected set of components that manages the operation and traffic of the cellular network. The cellular core network  130  also manages the traffic that flows between the cellular network and the Internet  140 . The core network  130  may include a location management function (LMF) to support location determinations for a UE. As will be described further below, in the exemplary aspects described herein, the LMF may instruct a serving cell to configure a target UE for SRS transmission, provide information to a plurality of positioning gNBs to monitor for and estimate the positioning SRS, receive the SRS measurements from the positioning gNBs and determine a position of the target UE from the SRS measurements. 
     The IMS  150  may be generally described as an architecture for delivering multimedia services to the UE  110  using the IP protocol. The IMS  150  may communicate with the cellular core network  130  and the Internet  140  to provide the multimedia services to the UE  110 . The network services backbone  160  is in communication either directly or indirectly with the Internet  140  and the cellular core network  130 . The network services backbone  160  may be generally described as a set of components (e.g., servers, network storage arrangements, etc.) that implement a suite of services that may be used to extend the functionalities of the UE  110  in communication with the various networks. 
       FIG.  2    shows an exemplary UE  110  according to various exemplary aspects. The UE  110  will be described with regard to the network arrangement  100  of  FIG.  1   . The UE  110  may represent any electronic device and may include a processor  205 , a memory arrangement  210 , a display device  215 , an input/output (I/O) device  220 , a transceiver  225 , and other components  230 . The other components  230  may include, for example, an audio input device, an audio output device, a battery that provides a limited power supply, a data acquisition device, ports to electrically connect the UE  110  to other electronic devices, sensors to detect conditions of the UE  110 , etc. 
     The processor  205  may be configured to execute a plurality of engines for the UE  110 . For example, the engines may include an SRS engine  235  for transmitting positioning SRS to each of a plurality of positioning nodes based on a network configuration for the positioning SRS. The positioning SRS is estimated by the positioning nodes to provide the network with information so that the network may determine a location of the UE, to be described in further detail below. 
     The above referenced engine being an application (e.g., a program) executed by the processor  205  is only exemplary. The functionality associated with the engines may also be represented as a separate incorporated component of the UE  110  or may be a modular component coupled to the UE  110 , e.g., an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry to receive signals and processing circuitry to process the signals and other information. The engines may also be embodied as one application or separate applications. In addition, in some UEs, the functionality described for the processor  205  is split among two or more processors such as a baseband processor and an applications processor. The exemplary aspects may be implemented in any of these or other configurations of a UE. 
     The memory  210  may be a hardware component configured to store data related to operations performed by the UE  110 . The display device  215  may be a hardware component configured to show data to a user while the I/O device  220  may be a hardware component that enables the user to enter inputs. The display device  215  and the I/O device  220  may be separate components or integrated together such as a touchscreen. The transceiver  225  may be a hardware component configured to establish a connection with the 5G-NR RAN  120 , the LTE RAN  122  etc. Accordingly, the transceiver  225  may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies). 
       FIG.  3    shows an exemplary network cell, in this case gNB  120 A, according to various exemplary aspects. As noted above with regard to the UE  110 , the gNB  120 A may represent a serving cell for the UE  110 . The gNB  120 A may represent any access node of the 5G NR network through which the UE  110  may establish a connection and manage network operations. Additionally, the gNB  120 A may represent a positioning node used in a positioning method implemented by the network to locate a target UE. The gNB  120 A illustrated in  FIG.  3    may also represent the gNB  120 B. 
     The gNB  120 A may include a processor  305 , a memory arrangement  310 , an input/output (I/O) device  320 , a transceiver  325 , and other components  330 . The other components  330  may include, for example, an audio input device, an audio output device, a battery, a data acquisition device, ports to electrically connect the gNB  120 A to other electronic devices, etc. 
     The processor  305  may be configured to execute a plurality of engines of the gNB  120 A. For example, when the gNB  120 A is a serving cell for a UE, the engines may include a UE configuration engine  335  for providing UE configuration information to the network, for example, information relating to periods when the UE is in a DRX inactive mode or has a measurement gap (MG). The network may then distribute the information to positioning nodes so that the positioning nodes may monitor. When the gNB  120 A is a positioning cell being used by the network to locate a UE, the engines may also include an SRS monitoring engine  340  for receiving the UE configuration information from the network and monitoring for positioning SRS from the UE in accordance therewith. For example, the gNB  120 A may determine a period during which it will monitor for the positioning SRS and a period during which it will not monitor for the positioning SRS based on the UE configuration information, to be described in further detail below, and estimate the positioning SRS when it is received from the UE. 
     The above noted engines each being an application (e.g., a program) executed by the processor  305  is only exemplary. The functionality associated with the engines may also be represented as a separate incorporated component of the gNB  120 A or may be a modular component coupled to the gNB  120 A, e.g., an integrated circuit with or without firmware. For example, the integrated circuit may include input circuitry to receive signals and processing circuitry to process the signals and other information. In addition, in some gNBs, the functionality described for the processor  305  is split among a plurality of processors (e.g., a baseband processor, an applications processor, etc.). The exemplary aspects may be implemented in any of these or other configurations of a gNB. 
     The memory  310  may be a hardware component configured to store data related to operations performed by the UEs  110 ,  112 . The I/O device  320  may be a hardware component or ports that enable a user to interact with the gNB  120 A. The transceiver  325  may be a hardware component configured to exchange data with the UEs  110 ,  112  and any other UE in the system  100 , e.g. if the gNB  120 A serves as a PCell or an SCell to either or both of the UEs  110 ,  112 . The transceiver  325  may operate on a variety of different frequencies or channels (e.g., set of consecutive frequencies). Therefore, the transceiver  325  may include one or more components (e.g., radios) to enable the data exchange with the various networks and UEs. 
     As discussed above, a UE may be configured with a discontinuous reception (DRX) cycle to save power. The DRX cycle utilizes an active mode of data exchange processing and a sleep mode of inactivity. The UE may use the active mode of processing at defined intervals to perform scheduled operations such as performing measurements related to the network conditions, transmitting (e.g., requests, measurement reports, uplink data etc.), and receiving (e.g. control channel information, reference signals, synchronization signals, downlink data, etc.). The time period that the UE may be scheduled to receive control channel information may be termed the OnDuration for the DRX cycle, or a DRX active time. The OnDuration relates to a duration during which the UE may perform operations that enable the UE to receive data that may be transmitted to the UE such as but not limited to, control channel information, an uplink grant, a downlink grant, reference signals, synchronization signals, payload data etc. 
     During the DRX cycle, when an OnDuration is not scheduled the UE may have an opportunity to utilize the sleep mode of inactivity and conserve power. This period may be referred to as a DRX inactive time. However, reference to a DRX cycle is for illustrative purposes, and different networks may refer to similar concepts by a different name. The exemplary aspects may apply to any scenario in which the UE transitions between a power saving mode, where certain operations are suspended, and an active mode, where the operations are resumed, with regard to data exchange processing. 
     The DRX cycle may have a predetermined duration N such as 100 milliseconds (ms), 50 ms, 40 ms, 20 ms, etc. For example, at a time 0, there may be a OnDuration during which the active mode of processing is used. Subsequently, upon the conclusion of the OnDuration, the UE has an opportunity to utilize the sleep mode of inactivity. Then at a time N, there may be another OnDuration. Subsequently, the sleep mode is used until a time 2N. This process continues for the duration of the DRX cycle. Reference to the sleep mode of inactivity does not necessarily mean putting the processor, the transmitter, and the receiver of the UE to sleep, in hibernation, or in deactivation. For example, the processor (e.g., baseband and/or application) may continue to execute other applications or processes. The sleep mode relates to conserving power by discontinuing a continuous processing functionality relating to operations that enable the UE to receive data that may be transmitted to the UE and transmit data to the network. Further, reference to the DRX cycle being configured in ms units is merely for illustrative purposes, the exemplary aspects may utilize a DRX cycle that is based on subframes or any other suitable unit of time. 
     A UE may further be configured with a measurement gap (MG) for performing frequency measurements while other capabilities, such as transmitting/receiving data, are suspended. The measurement gap configuration may depend on the capability of the UE, the active BWP and/or the operating frequency. The measurement gap may be of a predefined duration and repeat periodically. Typically, a UE will tune away from a currently connected network or frequency band during the measurement gap to measure signals associated with other networks and/or at different frequencies than on which it is currently operating. During this measurement gap, the UE is not available to the currently connected network, e.g., it is neither transmitting signals to nor receiving signals from the currently connected network. 
     In some methods for determining a position of a user equipment (UE), such as multiple round trip time (RTT) positioning or Uplink Time Difference of Arrival (UTDOA), a positioning SRS is transmitted from a target UE to a plurality of network nodes so that each of the nodes can estimate the uplink arrival timing from the UE. The network may then use the information provided by the positioning nodes to determine a position of the UE. 
       FIG.  4    shows a network arrangement  400  including a UE  402  and three gNBs  404  utilized in a positioning determination for the UE  402 . In the example of  FIG.  4   , it may be considered that the UE  402  may be similar to the UE  110  described with reference to  FIGS.  1  and  2   . It may also be considered that the gNBs  404  may be similar to the gNB  120 A and  120 B described with reference to  FIGS.  1  and  3   . In the arrangement  400 , the gNB  404   a  is a serving cell for the UE  402  and gNBs  404   b  and  404   c  may be configured by the network to be utilized as positioning nodes. The gNB  404   a  may also be used as a positioning node in the positioning method. The positioning gNBs  404   b  and  404   c  are configured to listen for and estimate positioning SRS transmitted from the UE  402  and provide the measurements to the network, for example via a location management function (LMF) at the 5G core network (5GC). The LMF may be considered a positioning server for coordinating the positioning SRS transmissions from the UE, providing information to the positioning nodes for monitoring for the positioning SRS, and receiving SRS estimations from the positioning nodes. 
     In a typical positioning method, such as multiple RTT or UTDOA, the LMF may request the serving gNB  404   a  to configure the UE  402  for the positioning SRS transmission, and knows the positioning SRS configuration from the serving gNB  404   a . The LMF distributes the positioning SRS configuration information to all of the positioning gNBs  404  so that, when the UE  402  transmits the positioning SRS to the positioning gNBs, the gNBs  404  may estimate the positioning SRS from the target UE  402  based on the information provided by the LMF. 
     One potential issue for these exemplary positioning methods is whether the LMF knows the exact information pertaining to when the UE will transmit the positioning SRS and/or when the UE will not transmit the positioning SRS. If the LMF is unaware of when the UE cannot transmit the SRS, gNB resources may be wasted when monitoring the positioning SRS from the UE. 
     In some exemplary aspects, a UE will not transmit periodic positioning SRS and semi-persistent (SP) positioning SRS outside the DRX active time, but may transmit aperiodic SRS (if configured by network) regardless of the DRX status. If positioning SRS transmissions follow these exemplary aspects, the positioning gNBs that are not serving cells for the UE will not understand when the UE will be transmitting SRSs. 
     The exemplary aspects relate to providing information to positioning gNBs for establishing monitoring periods to monitor for positioning SRS from a target UE, for example, in a positioning method for the target UE implemented by the network. The gNB monitoring may be dependent on a UE configuration for a DRX cycle and/or a measurement gap where the UE may be unable to transmit the positioning SRS. Each of these exemplary aspects will be described in greater detail below. 
       FIG.  5    shows a method  500  for locating a user equipment (UE). The method  500  will be described with reference to the network arrangement  400 . In  505 , a network (e.g., the LMF of core network  130 ) instructs a serving cell (e.g., gNB  404   a ) serving a UE (e.g., UE  402 ) to configure the UE  402  with a positioning SRS. 
     In  510 , the serving gNB  404   a  configures the UE  402  with the positioning SRS. For example, the UE  402  may be configured with time domain and frequency domain resources to transmit the positioning SRS. In  515 , the serving gNB  404   a  provides UE  402  configuration information to the network, e.g. the LMF, including, for example, DRX information and/or MG information. 
     In  520 , the network distributes the UE  402  configuration information to the positioning gNBs  404   b  and  404   c . In  525 , the positioning gNBs  404   b  and  404   c  (and the serving gNB  404   a  acting as a positioning gNB) monitor for the positioning SRS of the target UE  402  based on the UE configuration information. The gNBs  404   b  and  404   c  may monitor for a reduced duration, relative to a gNB having no knowledge of the UE configuration, thus saving resources of the gNB. In  530 , the positioning gNBs  404   a - c  provide their respective SRS estimations to the network. In  535 , the network determines a position of the UE  402  based on the SRS estimations provided by the positioning gNBs  404   a - c.    
     Relative to the first exemplary aspect described above, in a first option, the UE may be configured in the following manner based on, for example, network specifications. The UE is configured so that periodic and semi-persistent positioning SRSs cannot be transmitted during the DRX inactive time, while aperiodic positioning SRSs are transmitted regardless of the active/inactive time for DRX. The UE may alternately or additionally be configured so that no type of positioning SRS (periodic, semi-persistent, or aperiodic) can be transmitted within the measurement gap (MG). 
     In the first option, the serving gNB  404   a  of the target UE  402  may send the DRX information for the UE  402  to the core network  130 . For example, the gNB  404   a  may send the DRX information to the LMF via the NR Positioning Protocol A (NRPPa). The NRPPa includes procedures for handling the transfer of positioning related information between an NR node and the LMF. The DRX information may include (but is not limited to): DRX timing information, e.g. drx-LongCycleStartOffset, drx-ShortCycle, drx-ShortCycleTimer, drx-onDurationTimer, for indicating where the DRX active time and inactive time are for the UE, and a reference time for the DRX timeline that is used by the LMF to understand the absolute timing of the DRX on the UE. The reference time is used because the timing of the UE/gNB may be different from a local time at the LMF. 
     The serving gNB  404   a  of the target UE  402  may additionally or alternatively send UE measurement gap (MG) information to the LMF via the NRPPa. The MG information may include (but is not limited to): MG timing information, e.g. MGRP (Measurement gap repetition period), MGL (Measurement gap length), MGTA (Measurement gap timing advance), and a reference time for the MG timeline. Similar to the DRX reference time, the MG reference time is used by the LMF to understand the absolute timing of the MG on the UE. 
     The LMF distributes the above mentioned DRX information (if used) and MG information (if used) to all positioning gNBs, e.g., gNBs  404   b  and  404   c.    
     In other exemplary aspects, the UE  402  is configured in a similar manner to the first option. For example, the UE  402  is configured so that periodic and semi-persistent positioning SRSs are not transmitted during the DRX inactive time, while aperiodic positioning SRSs are transmitted regardless of the active/inactive time for DRX. The UE  402  is further configured so that no type of positioning SRS can be transmitted within the measurement gap (MG). 
     In these aspects, the positioning gNBs  404   b - c  do not receive any DRX or MG information from the serving gNB  404   a . The positioning gNBs  404   b - c  will attempt to receive the positioning SRS from the UE  402  regardless of the DRX and MG status of the UE  402 , e.g., the positioning gNBs  404   b - c  will listen for the positioning SRS from the UE  402  during a time period the gNBs  404   b - c  expect that the UE  402  is transmitting positioning SRS without regard to the DRX or MG status of the UE  402 . 
     Relative to the first exemplary aspect described above, in a second option, a UE is configured so that periodic and semi-persistent positioning SRS are not transmitted during the DRX inactive time, while aperiodic positioning SRS are transmitted regardless of the active/inactive time for DRX, similar to the first option. However, in the second option, the UE may support a per-frame measurement gap. If the UE supports only per-UE MG (e.g., a same measurement gap applied to both FR1 and FR2), positioning SRS cannot be transmitted within the MG, similar to the first option. If the UE supports per-FR MG (e.g., two independent gap patterns are defined for FR1 and FR2, respectively), then the positioning SRS in FR1 cannot be transmitted within the FR1 MG, but may be transmitted within the FR2 MG. Positioning SRS in FR2 cannot be transmitted within the FR2 MG, but may be transmitted within the FR1 MG. If per-UE MG is configured by the network, then positioning SRS (in FR1 or FR2) cannot be transmitted within per-UE MG. 
     In the second option, similar to the first option, the serving gNB  404   a  of the target UE  402  may send the DRX information to the LMF via the NRPPa. The DRX information may include the same information discussed above relative to the first option, i.e., DRX timing information, e.g. drx-LongCycleStartOffset, drx-ShortCycle, drx-ShortCycleTimer, drx-onDurationTimer, for indicating where the DRX active time and inactive time are for the UE  402 , and a reference time for the DRX timeline that is used by the LMF to understand the absolute timing of the DRX for the UE  402 . 
     The serving gNB  404   a  of the target UE  402  may additionally or alternatively send UE measurement gap (MG) information to the LMF via the NRPPa. In the second option, the MG information includes the MG type, e.g. per-UE MG, FR1 MG or FR2 MG. The MG information may further include (but is not limited to): MG timing information, e.g. MGRP (Measurement gap repetition period), MGL (Measurement gap length), MGTA (Measurement gap timing advance), and a reference time for the MG timeline. The LMF distributes the above mentioned DRX (if configured) and MG information (if configured) to all positioning gNBs  404   b - c.    
     In other exemplary aspects, the UE  402  is configured in a similar manner to the second option discussed above. For example, the UE  402  is configured so that periodic and semi-persistent positioning SRS are not transmitted during the DRX inactive time, while aperiodic positioning SRSs are transmitted regardless of the active/inactive time for DRX. If the UE  402  supports only per-UE MG (e.g., a same measurement gap applied to both FR1 and FR2), all types of positioning SRS cannot be transmitted within the MG. Otherwise, if the UE supports per-FR MG (e.g., two independent gap patterns are defined for FR1 and FR2, respectively), then the positioning SRS in FR1 cannot be transmitted within the FR1 MG, but may be transmitted within the FR2 MG. Positioning SRS in FR2 cannot be transmitted within the FR2 MG, but may be transmitted within the FR1 MG. If per-UE MG is configured by the network, then all types of positioning SRS (in FR1 or FR2) cannot be transmitted within per-UE MG. 
     In these exemplary aspects, the positioning gNBs  404   b - c  do not receive any DRX or MG information from the serving gNB  404   a . The positioning gNBs  404   b - c  will attempt to receive the positioning SRS from the UE  402  regardless of the DRX status of the UE  402 . For MG, the positioning gNBs  404   b - c  will attempt to receive the positioning SRS from the UE outside the corresponding MG duration. 
     In the exemplary aspects discussed above, the UE was limited to transmitting the periodic and SP positioning SRS during the DRX active state only. According to further exemplary aspects, the UE is allowed to transmit periodic and SP positioning SRS during the DRX inactive time. 
     In a first option, when the UE  402  is allowed to transmit the positioning SRS during the inactive time, the UE  402  may decide whether to transmit a configured periodical or SP positioning SRS during the DRX inactive time based on various considerations. For example, in one aspect, the UE  402  may determine to transmit or to not transmit based on a power consumption evaluation. In another aspect, the UE  402  may determine to not transmit a positioning SRS, or alternatively, to transmit the positioning SRS, if this positioning SRS is also configured for a purpose other than positioning (e.g. UL channel estimation). 
     In these aspects, all positioning gNBs  404   a - c  will monitor for the positioning SRS regardless of UE DRX status, even if it is uncertain as to whether the UE  402  will transmit the positioning SRS during the inactive period. 
     In a second option, when the UE  402  is allowed to transmit during the inactive period, the UE  402  may be required by the network to transmit a configured periodical or SP positioning SRS in the DRX inactive time. In these aspects, all positioning gNBs  404   a - c  will monitor all those positioning SRS regardless of UE DRX status. 
     In other exemplary aspects, the serving cell  404   a  may configure the UE  402  so that the SRS signaling period is not scheduled during a DRX inactive period.  FIG.  6    shows a method  600  for preventing a positioning SRS signaling period from being aligned with a DRX inactive time for a user equipment (UE). In  605 , after configuring the positioning SRS for the UE  402 , the serving gNB  404   a  checks the UE DRX status and the periodical or SP positioning SRS configurations for the UE  402 . In  610 , the serving gNB  404   a  compares the DRX and SRS configurations. Specifically, the serving gNB  404   a  compares the timing of the DRX inactive time relative to the timing of the SRS transmission. 
     In  615 , if the configured periodical or SP positioning SRS is located within the inactive time of the DRX, the serving gNB  404   a  changes the DRX configuration of the UE  402 . In one option, the serving gNB  404   a  changes the DRX configuration so that the configured periodical or SP positioning SRS is located within the active time of the DRX. In another option, the serving gNB  404   a  changes the DRX configuration of the UE  402  to non-DRX. In non-DRX, the UE  402  is required to transmit all the configured periodical or SP positioning SRS at the allocated time. 
     Alternatively, in  620 , if the configured periodical or SP positioning SRS is located within the inactive time of the DRX, the serving gNB  404   a  changes the UE  402  periodical or SP positioning SRS. In one option, the serving gNB  404   a  changes the periodical or SP positioning SRS of the UE  402  so that the re-configured periodical or SP positioning SRS is located within the active time of the DRX. In another option, the serving gNB  404   a  changes the periodical or SP positioning SRS of the UE  402  to aperiodical SRS. In an aperiodical SRS configuration, the UE  402  transmits the aperiodical positioning SRS based on a network indication. 
     Those skilled in the art will understand that the above-described exemplary aspects may be implemented in any suitable software or hardware configuration or combination thereof. An exemplary hardware platform for implementing the exemplary aspects may include, for example, an Intel x86 based platform with compatible operating system, a Windows OS, a Mac platform and MAC OS, a mobile device having an operating system such as iOS, Android, etc. In a further example, the exemplary aspects of the above described method may be embodied as a program containing lines of code stored on a non-transitory computer readable storage medium that, when compiled, may be executed on a processor or microprocessor. 
     It is well understood that the use of personally identifiable information should follow privacy policies and practices that are generally recognized as meeting or exceeding industry or governmental requirements for maintaining the privacy of users. In particular, personally identifiable information data should be managed and handled so as to minimize risks of unintentional or unauthorized access or use, and the nature of authorized use should be clearly indicated to users. 
     Although this application described various aspects each having different features in various combinations, those skilled in the art will understand that any of the features of one aspect may be combined with the features of the other aspects in any manner not specifically disclaimed or which is not functionally or logically inconsistent with the operation of the device or the stated functions of the disclosed aspects. 
     It will be apparent to those skilled in the art that various modifications may be made in the present disclosure, without departing from the spirit or the scope of the disclosure. Thus, it is intended that the present disclosure cover modifications and variations of this disclosure provided they come within the scope of the appended claims and their equivalent.

Metadata:
Filing Date: 20210803
Publication Date: 20240723
Grant Date: 20240723
Priority Date: 20200805
Inventors: CUI, JIE
ZHANG, DAWEI
HE, HONG
RAGHAVAN, Manasa
YANG, WEIDONG
TANG, YANG
WU, ZHIBIN
Assignee: APPLE INC
CPC Classifications: [{"code": "H04W24/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W48/12", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L5/0069", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L5/0082", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L5/0091", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/28", "inventive": false, "first": false, "tree": "[]"}, {"code": "H04L5/0048", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W76/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L5/0051", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04L5/0048", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W64/00", "inventive": true, "first": true, "tree": "[]"}, {"code": "H04W76/28", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/10", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04W24/08", "inventive": true, "first": false, "tree": "[]"}, {"code": "H04L5/0051", "inventive": true, "first": true, "tree": "[]"}]
Family ID: 80114286