Patent Description:
New Radio (NR) (also known as "<NUM>" or Next Generation or NG) architecture is being discussed in the 3rd Generation Partnership Project (3GPP). A NR current concept is illustrated in <FIG>, which may include a wireless device (WD) <NUM>, a NG Radio Access Network <NUM> (NG-RAN), an access and mobility management function (AMF) <NUM> and a location management function (LMF) <NUM>; where the NG-RAN <NUM> comprises a Node1 and Node2 denoting NR base stations (BSs) (one NR BS may correspond to one or more transmission/reception points (TRPs)) and the lines between the nodes illustrate the corresponding interfaces. Node1 and Node2 may not always both be present. When both are present, the Next Generation Control Plane (NG-C) interface is only present for one of them.

A Local Management Function (LMF) is the location node in NR. There may also be interactions between the location node and the network node via the NR Positioning Protocol A (NRPPa) (not illustrated in <FIG>) and between the wireless device (WD) and the location server via NR Long-Term Evolution Positioning Protocol (LPP). The interactions between the network node and the WD are supported via the Radio Resource Control (RRC) protocol.

In NR, several round trip time (RTT) positioning measurements are specified. Examples are the WD receive (Rx) - transmit (Tx) time difference, the network node Rx-Tx time difference, the time advance (TA), etc..

The WD Rx-Tx time difference is defined as TWD-RX -TWD-TX,
where:.

The network node Rx-Tx time difference is defined as TNN-RX - TNN-TX,
where:.

Reference signals may be used for NR RTT positioning measurements. Positioning reference signals (PRS) may be periodically transmitted on a positioning frequency layer in PRS resources in the downlink (DL) by the network node. The information about the PRS resources is signaled to the WD by the positioning node via higher layers but may also be provided by a network node such as a base station, e.g., via broadcast. Each positioning frequency layer comprises PRS resource sets, where each PRS resource set comprises one or more PRS resources. All the DL PRS resources within one PRS resource set are configured with the same periodicity.

The PRS resource periodicity (TperPRS) comprises:
TperPRS ∈ <NUM>µ {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>} slots, where µ=<NUM>, <NUM>, <NUM>, <NUM> for PRS Subcarrier Spacing (SCS) of <NUM>, <NUM>, <NUM> and <NUM> respectively. TperPRS = <NUM>µ · <NUM> is not supported for µ=<NUM>.

Each PRS resource can also be repeated within one PRS resource set and takes values TperPRS ∈ {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>}.

PRS are transmitted in a consecutive number of symbols (LPRS) within a slot: LPRS ∈{<NUM>, <NUM>, <NUM>, <NUM>}. The following DL PRS Resource Element (RE) patterns, with comb size KPRS equal to number of symbols LPRS are supported:.

Maximum PRS bandwidth (BW) is <NUM> Physical Resource Blocks (PRBs). Minimum PRS BW is <NUM> PRBs. The configured PRS BW may be a multiple of <NUM>.

Sounding reference signals are also for positioning. For positioning measurement, the WD can be configured (typically by the serving base station) with SRS resource for SRS transmission in NS ∈ {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>} number of adjacent symbols anywhere within the slot. The periodic SRS resource can be configured with a periodicity (TSRS):
TSRS ∈ {<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>} slots.

In the existing systems (e.g., in 3GPP Long-Term Evolution (LTE) positioning), the bidirectional measurements (e.g., WD Rx-Tx) are performed on Cell Specific Reference Signals (CRS) and SRS and always with respect to the serving cell. In LTE, the CRS are transmitted by the base station in every subframe, while the SRS can be configured with different periodicities. In order to achieve sufficient WD Rx-Tx measurement accuracy, the WD obtains and combines several samples of RX-TX time differences over a certain layer-<NUM> measurement period (T0). In existing solutions like in LTE due to the frequently available CRS, the WD has a lot of freedom in terms of obtaining samples for the RTT measurement. However, in NR both CRS and SRS can be configured with different periodicities. The PRS periodicity can vary over an especially large range. This leads to additional complexity in the WD to accurately measure the RTT measurement. As a result, the WD may have to store the RX and/or TX measurement samples for a very long time before deriving the RX-TX time difference, draining its memory and increasing processing but also impacting the positioning accuracy in the end.

<CIT> describes systems, apparatus and methods for determining a cyclic shift diversity (CSD) mode. Examples use a channel impulse response (CIR) to determine a current CSD mode. Specifically, a channel impulse response from an orthogonal frequency-division multiplexing (OFDM) symbol, which forms CIR samples. The CIR samples are examined to find a local maxima. A current CSD mode may be selected based on the local maxima found in the CIR samples.

The invention provides methods, systems, and apparatuses for performing a more accurate round trip time measurement between two or more nodes or devices over a measurement time.

Some embodiments described herein may enhance the performance of RTT positioning measurements regardless of the periodicities of PRS and SRS configured for the positioning measurement. The methods may further define WD behavior and provide consistent performance for RTT positioning measurements. The methods may also enable the network node (e.g. positioning node) to interpret RTT positioning measurement results reported by the WD.

Before describing in detail exemplary embodiments, it is noted that the embodiments reside primarily in combinations of apparatus components and processing steps related to performing a round trip time (RTT) measurement between two nodes or devices over a measurement time (Tm). Accordingly, components have been represented where appropriate by conventional symbols in the drawings, showing only those specific details that are pertinent to understanding the embodiments so as not to obscure the disclosure with details that will be readily apparent to those of ordinary skill in the art having the benefit of the description herein.

It is noted that, in this disclosure, the general term node is used which can be a network node or a wireless device (WD).

The term radio access technology (RAT) may refer to any RAT e.g. Universal Terrestrial Radio Access (UTRA), Evolved Universal Terrestrial Radio Access (E-UTRA), narrow band internet of things (NB-IoT), WiFi, Bluetooth, next generation RAT, New Radio (NR), Fourth Generation (<NUM>), Fifth Generation (<NUM>), etc. Any of the equipment denoted by the term node, network node or radio network node may be capable of supporting a single or multiple RATs.

The term signal or radio signal used herein can be any physical signal or physical channel. Examples of down link (DL) physical signals are reference signal such as Primary Synchronization Signal (PSS), Secondary Synchronization Signal (SSS), Channel State Information Reference Signal (CSI-RS), DeModulation Reference Signal (DMRS), signals in Synchronization Signal Block (SSB), Downlink Reference Signal (DRS), cell specific reference signal (CRS), positioning reference signal (PRS) etc. Examples of uplink (UL) physical signals are reference signal such as Sounding Reference Signal (SRS), DMRS etc. The term physical channel refers to any channel carrying higher layer information, e.g. data, control etc. Examples of physical channels are Physical Broadcast Channel (PBCH), Narrow Band Physical Broadcast Channel (NPBCH), Physical Downlink Control Channel (PDCCH), Physical Downlink Shared Channel (PDSCH), Shortened Physical Uplink Control Channel (sPUCCH), Shortened Physical Downlink Control Channel (sPDSCH), Shortened Physical Uplink Control Channel (sPUCCH), Shortened Physical Uplink Shared Channel (sPUSCH), MTC Physical Downlink Control Channel (MPDCCH), Narrow Band Physical Downlink Control Channel (NPDCCH), Narrow Band Physical Downlink Shared Channel (NPDSCH), Enhanced Physical Downlink Control Channel (E-PDCCH), Physical Uplink Shared Channel (PUSCH), Physical Uplink Control Channel (PUCCH), Narrow Band Physical Uplink Shared Channel (NPUSCH) etc..

The term time resource used herein may correspond to any type of physical resource or radio resource expressed in terms of length of time. Examples of time resources are symbol, time slot, subframe, radio frame, TTI, interleaving time, slot, sub-slot, mini-slot, etc..

The term "network node" used herein can be any kind of network node comprised in a radio network which may further comprise any of base station (BS), radio base station, base transceiver station (BTS), base station controller (BSC), radio network controller (RNC), g Node B (gNB), evolved Node B (eNB or eNodeB), Node B, multi-standard radio (MSR) radio node such as MSR BS, multi-cell/multicast coordination entity (MCE), integrated access and backhaul (IAB) node, relay node, donor node controlling relay, radio access point (AP), transmission points, transmission nodes, Remote Radio Unit (RRU) Remote Radio Head (RRH), a core network node (e.g., mobile management entity (MME), self-organizing network (SON) node, a coordinating node, positioning node, MDT node, etc.), an external node (e.g., 3rd party node, a node external to the current network), nodes in distributed antenna system (DAS), a spectrum access system (SAS) node, an element management system (EMS), etc. The network node may also comprise test equipment.

The WD may also be a radio communication device, target device, device to device (D2D) WD, machine type WD or WD capable of machine to machine communication (M2M), low-cost and/or low-complexity WD, a sensor equipped with WD, Tablet, mobile terminals, smart phone, laptop embedded equipped (LEE), laptop mounted equipment (LME), USB dongles, Customer Premises Equipment (CPE), an Internet of Things (IoT) device, or a Narrowband IoT (NB-IOT) device, etc..

Embodiments provide for more accurate round trip time (RTT) measurements between two nodes or devices over a measurement time (Tm).

Referring again to the drawing figures, in which like elements are referred to by like reference numerals, there is shown in <FIG> a schematic diagram of a communication system <NUM>, according to an embodiment, such as a 3GPP-type cellular network that may support standards such as LTE and/or NR (<NUM>), which comprises an access network <NUM>, such as a radio access network, and a core network <NUM>. The access network <NUM> comprises a plurality of network nodes 16a, 16b, 16c (referred to collectively as network nodes <NUM>), such as NBs, eNBs, gNBs or other types of wireless access points, each defining a corresponding coverage area 18a, 18b, 18c (referred to collectively as coverage areas <NUM>). Each network node 16a, 16b, 16c is connectable to the core network <NUM> over a wired or wireless connection <NUM>. A first wireless device (WD) 22a located in coverage area 18a is configured to wirelessly connect to, or be paged by, the corresponding network node 16a. A second WD 22b in coverage area 18b is wirelessly connectable to the corresponding network node 16b. While a plurality of WDs 22a, 22b (collectively referred to as wireless devices <NUM>) are illustrated in this example, the disclosed embodiments are equally applicable to a situation where a sole WD is in the coverage area or where a sole WD is connecting to the corresponding network node <NUM>. Note that although only two WDs <NUM> and three network nodes <NUM> are shown for convenience, the communication system may include many more WDs <NUM> and network nodes <NUM>.

The communication system <NUM> may itself be connected to a host computer <NUM>, which may be embodied in the hardware and/or software of a standalone server, a cloudimplemented server, a distributed server or as processing resources in a server farm.

A network node <NUM> is configured to include a Node RTT Measurement Unit <NUM> which is configured to perform at least one round trip time measurement over Tm wherein the RTT measurement is a function of at least an association between a periodicity (TRS1) of a first reference signal (RS1) transmitted from the network node to the WD and a periodicity (TRS2) of a second reference signal (RS2) transmitted from the WD to the node. In some embodiments, network node <NUM> is configured to include a Node RTT Measurement Unit <NUM> which is configured to perform at least one round trip time, RTT, measurement over a measurement time, the measurement time being a function of at least an association between a first periodicity of a first reference signal and a second periodicity of a second reference signal, the first reference signal being received by the network node from a wireless device, WD, and the second reference signal being transmitted from the network node to the WD; and optionally, use the at least one RTT measurement for an operational task.

A wireless device <NUM> may be configured to include a WD RTT Measurement Unit <NUM> which is configured to perform at least one RTT measurement over Tm, the at least one RTT measurement being a function of at least an association between TRS1 of RS1 transmitted from the WD to the at least one of a network node and a second WD and TRS2 of RS2 transmitted from the at least one of a network node and a second WD to the WD.

In some embodiments, wireless device <NUM> may be configured to include a WD RTT Measurement Unit <NUM> which is configured to perform at least one round trip time, RTT, measurement over a measurement time, Tm, the measurement time being a function of at least an association between a first periodicity, TRS1, of a first reference signal and a second periodicity, TRS2, of a second reference signal, the first reference signal being transmitted from the WD to a network node and the second reference signal being received by the WD from the network node; and optionally, report a result of the at least one RTT measurement.

The host application <NUM> may be operable to provide a service to a remote user, such as a WD <NUM> connecting via an OTT connection <NUM> terminating at the WD <NUM> and the host computer <NUM>. The "user data" may be data and information described herein as implementing the described functionality. In one embodiment, the host computer <NUM> may be configured for providing control and functionality to a service provider and may be operated by the service provider or on behalf of the service provider. The processing circuitry <NUM> of the host computer <NUM> may enable the host computer <NUM> to observe, monitor, control, transmit to and/or receive from the network node <NUM> and or the wireless device <NUM>.

Thus, the network node <NUM> further has software <NUM> stored internally in, for example, memory <NUM>, or stored in external memory (e.g., database, storage array, network storage device, etc.) accessible by the network node <NUM> via an external connection. The processing circuitry <NUM> may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by network node <NUM>. Processor <NUM> corresponds to one or more processors <NUM> for performing network node <NUM> functions described herein. The memory <NUM> is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software <NUM> may include instructions that, when executed by the processor <NUM> and/or processing circuitry <NUM>, causes the processor <NUM> and/or processing circuitry <NUM> to perform the processes described herein with respect to network node <NUM>. For example, processing circuitry <NUM> of the network node <NUM> may include Node RTT Measurement Unit <NUM> configured to perform at least one round trip time measurement over Tm wherein the RTT measurement is a function of at least an association between a periodicity (TRS1) of a first reference signal (RS1) transmitted from the network node to the WD and a periodicity (TRS2) of a second reference signal (RS2) transmitted from the WD to the node.

The processing circuitry <NUM> may be configured to control any of the methods and/or processes described herein and/or to cause such methods, and/or processes to be performed, e.g., by WD <NUM>. The processor <NUM> corresponds to one or more processors <NUM> for performing WD <NUM> functions described herein. The WD <NUM> includes memory <NUM> that is configured to store data, programmatic software code and/or other information described herein. In some embodiments, the software <NUM> and/or the client application <NUM> may include instructions that, when executed by the processor <NUM> and/or processing circuitry <NUM>, causes the processor <NUM> and/or processing circuitry <NUM> to perform the processes described herein with respect to WD <NUM>. For example, the processing circuitry <NUM> of the wireless device <NUM> may include a WD RTT Measurement Unit <NUM> configured to perform at least one RTT measurement over Tm, the at least one RTT measurement being a function of at least an association between TRS1 of RS1 transmitted from the WD to the at least one of a network node and a second WD and TRS2 of RS2 transmitted from the at least one of a network node and a second WD to the WD.

Although <FIG> and <FIG> show various "units" such as Node RTT Measurement Unit <NUM>, and WD RTT Measurement Unit <NUM> as being within a respective processor, it is contemplated that these units may be implemented such that a portion of the unit is stored in a corresponding memory within the processing circuitry. In other words, the units may be implemented in hardware or in a combination of hardware and software within the processing circuitry.

<FIG> is a flowchart illustrating an exemplary method implemented in a communication system, such as, for example, the communication system of <FIG> and <FIG>, in accordance with one embodiment. The communication system may include a host computer <NUM>, a network node <NUM> and a WD <NUM>, which may be those described with reference to <FIG>. In a first step of the method, the host computer <NUM> provides user data (Block S100). In an optional substep of the first step, the host computer <NUM> provides the user data by executing a host application, such as, for example, the host application <NUM> (Block S102). In a second step, the host computer <NUM> initiates a transmission carrying the user data to the WD <NUM> (Block S <NUM>). In an optional third step, the network node <NUM> transmits to the WD <NUM> the user data which was carried in the transmission that the host computer <NUM> initiated, in accordance with the teachings of the embodiments described throughout this disclosure (Block S106). In an optional fourth step, the WD <NUM> executes a client application, such as, for example, the client application <NUM>, associated with the host application <NUM> executed by the host computer <NUM> (Block S108).

<FIG> is a flowchart illustrating an exemplary method implemented in a communication system, such as, for example, the communication system of <FIG>, in accordance with one embodiment. The communication system may include a host computer <NUM>, a network node <NUM> and a WD <NUM>, which may be those described with reference to <FIG> and <FIG>. In a first step of the method, the host computer <NUM> provides user data (Block S110). In an optional substep (not shown) the host computer <NUM> provides the user data by executing a host application, such as, for example, the host application <NUM>. In a second step, the host computer <NUM> initiates a transmission carrying the user data to the WD <NUM> (Block S112). In an optional third step, the WD <NUM> receives the user data carried in the transmission (Block S114).

<FIG> is a flowchart illustrating an exemplary method implemented in a communication system, such as, for example, the communication system of <FIG>, in accordance with one embodiment. The communication system may include a host computer <NUM>, a network node <NUM> and a WD <NUM>, which may be those described with reference to <FIG> and <FIG>. In an optional first step of the method, the WD <NUM> receives input data provided by the host computer <NUM> (Block S116). In an optional substep of the first step, the WD <NUM> executes the client application <NUM>, which provides the user data in reaction to the received input data provided by the host computer <NUM> (Block S118). Additionally or alternatively, in an optional second step, the WD <NUM> provides user data (Block S120). In an optional substep of the second step, the WD provides the user data by executing a client application, such as, for example, client application <NUM> (Block S122). In providing the user data, the executed client application <NUM> may further consider user input received from the user. Regardless of the specific manner in which the user data was provided, the WD <NUM> may initiate, in an optional third substep, transmission of the user data to the host computer <NUM> (Block S124). In a fourth step of the method, the host computer <NUM> receives the user data transmitted from the WD <NUM>, in accordance with the teachings of the embodiments described throughout this disclosure (Block S126).

<FIG> is a flowchart illustrating an exemplary method implemented in a communication system, such as, for example, the communication system of <FIG>, in accordance with one embodiment. The communication system may include a host computer <NUM>, a network node <NUM> and a WD <NUM>, which may be those described with reference to <FIG> and <FIG>. In an optional first step of the method, in accordance with the teachings of the embodiments described throughout this disclosure, the network node <NUM> receives user data from the WD <NUM> (Block S128). In an optional second step, the network node <NUM> initiates transmission of the received user data to the host computer <NUM> (Block S130). In a third step, the host computer <NUM> receives the user data carried in the transmission initiated by the network node <NUM> (Block S132).

<FIG> is a flowchart of an exemplary process in a network node <NUM> for performing at least one round trip time (RTT) measurement over a measurement time (Tm) according to some embodiments of the present disclosure. One or more Blocks and/or functions performed by network node <NUM> may be performed by one or more elements of network node <NUM> such as by Node RTT Measurement Unit <NUM> in processing circuitry <NUM>, processor <NUM>, communication interface <NUM>, radio interface <NUM>, etc. In one or more embodiments, network node <NUM> such as via one or more of processing circuitry <NUM>, processor <NUM>, radio interface <NUM> and communication interface <NUM> is configured to perform (Block S <NUM>) at least one RTT measurement over Tm, the RTT measurement being a function of at least an association between a periodicity (TRS1) of a first reference signal (RS1) transmitted from the network node to at least one of a second network node and a wireless device (WD) and a periodicity (TRS2) of a second reference signal (RS2) transmitted from the at least one of a second network node and a WD.

In one or more embodiments, RS1 further comprises a sounding reference signal (SRS) and RS2 further comprises a positioning reference signal (PRS).

In one or more embodiments, RS1 further comprises a positioning reference signal (PRS) and the RS2 further comprises a sounding reference signal (SRS).

In one or more embodiments, Tm is further a function of at least one of the periodicity of a WD's activity level and a measurement gap.

In one or more embodiments, RS1 is specific to a WD.

In one or more embodiments, network node <NUM> such as via one or more of processing circuitry <NUM>, processor <NUM>, radio interface <NUM> and communication interface <NUM> is configured to transmit RS1 based on a timing advance with respect to the at least one of a second network node and a WD.

In one or more embodiments, network node <NUM> such as via one or more of processing circuitry <NUM>, processor <NUM>, radio interface <NUM> and communication interface <NUM> is configured to perform an RTT measurement over Tm between the network node and a plurality of other nodes.

In one or more embodiments, network node <NUM> such as via one or more of processing circuitry <NUM>, processor <NUM>, radio interface <NUM> and communication interface <NUM> is configured to perform multiple RTT measurements between the network node and the plurality of other nodes without any measurement gaps between the RTT measurements, performing multiple RTT measurements between the network node and the plurality of other nodes with measurement gaps between the RTT measurements and configuring a WD activity level when performing the multiple RTT measurements.

<FIG> is a flowchart of an exemplary process in a wireless device <NUM> for performing at least one round trip time measurement over a measurement time according to some embodiments of the present disclosure. One or more Blocks and/or functions performed by wireless device <NUM> may be performed by one or more elements of wireless device <NUM> such as by WD RTT Measurement Unit <NUM> in processing circuitry <NUM>, processor <NUM>, radio interface <NUM>, etc. In one or more embodiments, wireless device <NUM> such as via one or more of processing circuitry <NUM>, processor <NUM> and radio interface <NUM> is configured to perform (Block S <NUM>) at least one RTT measurement over Tm, the RTT measurement being a function of at least an association between a periodicity (TRS1) of a first reference signal (RS <NUM>) transmitted from the network node to at least one of a second network node and a wireless device (WD) and a periodicity (TRS2) of a second reference signal (RS2) transmitted from the at least one of a second network node and a WD to the network node.

In one or more embodiments, RS1 further comprises a sounding reference signal (SRS) and RS2 further comprises a positioning reference signal (PRS). In one or more embodiments, RS1 further comprises a positioning reference signal (PRS) and the RS2 further comprises a sounding reference signal (SRS). In one or more embodiments, Tm is further a function of at least one of the periodicity of a WD's activity level and a measurement gap. In one or more embodiments, RS1 is specific to a WD. In one or more embodiments, WD <NUM> such as via one or more of processing circuitry <NUM>, processor <NUM> and radio interface <NUM> is configured to transmit RS1 based on a timing advance with respect to the at least one of a second network node and a WD.

In one or more embodiments, WD <NUM> such as via one or more of processing circuitry <NUM>, processor <NUM> and radio interface <NUM> is configured to perform an RTT measurement over Tm between the network node and a plurality of other nodes.

In one or more embodiments, WD <NUM> such as via one or more of processing circuitry <NUM>, processor <NUM> and radio interface <NUM> is configured to one or more of perform multiple RTT measurements between the network node and the plurality of other nodes without any measurement gaps between the RTT measurements, perform multiple RTT measurements between the network node and the plurality of other nodes with measurement gaps between the RTT measurements and configure a WD activity level when performing the multiple RTT measurements.

<FIG> is a flowchart of an exemplary process in a network node <NUM> for performing at least one round trip time (RTT) measurement over a measurement time (Tm) according to some embodiments of the present disclosure. One or more Blocks and/or functions performed by network node <NUM> may be performed by one or more elements of network node <NUM> such as by Node RTT Measurement Unit <NUM> in processing circuitry <NUM>, processor <NUM>, communication interface <NUM>, radio interface <NUM>, etc. In one or more embodiments, network node <NUM> such as via one or more of processing circuitry <NUM>, processor <NUM>, radio interface <NUM> and communication interface <NUM> is configured to: perform (Block S138) at least one round trip time, RTT, measurement over a measurement time, the measurement time being a function of at least an association between a first periodicity of a first reference signal and a second periodicity of a second reference signal, the first reference signal being received by the network node from a wireless device, WD, and the second reference signal being transmitted from the network node to the WD; and optionally, use (Block S140) the at least one RTT measurement for an operational task.

In some embodiments, the first reference signal is a sounding reference signal, SRS, and the second reference signal is a positioning reference signal, PRS; and the first periodicity is a periodicity of the SRS and the second periodicity is a periodicity of the PRS. In some embodiments, the association between the first periodicity and the second periodicity comprises at least one relation associated with the first periodicity and the second periodicity. In some embodiments, the at least one relation includes at least one of: a maximum of the first periodicity and the second periodicity; a minimum of the first periodicity and the second periodicity; and a difference between the first periodicity and the second periodicity.

In some embodiments, the at least one relation includes at least one of: a mean of at least the first periodicity and the second periodicity; a least common multiple of at least the first periodicity and the second periodicity; and a modulus operation comprising the first periodicity and the second periodicity. In some embodiments, the at least one relation depends on a condition. In some embodiments, a first relation is used when the condition is met; otherwise, a second relation is used. In some embodiments, the condition is based at least in part on a threshold value, the first relation being used when the threshold value is exceeded; otherwise, the second relation is used. In some embodiments, the condition is based further on a third relation, the first relation being used when the threshold value is exceeded by the third relation; otherwise, the second relation is used.

In some embodiments, the measurement time is the function of the association between the first periodicity and the second periodicity when a condition is met; otherwise, the measurement time is not a function of the association. In some embodiments, the condition comprises a configured value, the measurement time is the function of the association when the configured value is met; otherwise, the measurement time is not a function of the association. In some embodiments, the condition comprises a threshold value, the measurement time is the function of the association when the threshold value is exceeded; otherwise, the measurement time is not a function of the association. In some embodiments, the measurement time is further the function of at least one of a minimum duration for the measurement time and a scaling factor.

In some embodiments, the measurement time is a maximum of the association and the at least one of the minimum duration for the measurement time and the scaling factor. In some embodiments, performing the at least one RTT measurement further comprises performing, such as via one or more of processing circuitry <NUM>, processor <NUM>, radio interface <NUM> and communication interface <NUM>, multiple RTT measurements associated with multiple different nodes.

<FIG> is a flowchart of an exemplary process in a wireless device <NUM> for performing at least one round trip time measurement over a measurement time according to some embodiments of the present disclosure. One or more Blocks and/or functions performed by wireless device <NUM> may be performed by one or more elements of wireless device <NUM> such as by WD RTT Measurement Unit <NUM> in processing circuitry <NUM>, processor <NUM>, radio interface <NUM>, etc. In one or more embodiments, wireless device <NUM> such as via one or more of processing circuitry <NUM>, processor <NUM> and radio interface <NUM> is configured to perform (Block S <NUM>) at least one round trip time, RTT, measurement over a measurement time, Tm, the measurement time being a function of at least an association between a first periodicity, TRS1, of a first reference signal and a second periodicity, TRS2, of a second reference signal, the first reference signal being transmitted from the WD to a network node and the second reference signal being received by the WD from the network node. Next, the WD uses the at least one RTT measurement for one or more operational tasks, which in this example is reporting a result of the at least one RTT measurement (Block S144).

In some embodiments, the first reference signal is a sounding reference signal, SRS, and the second reference signal is a positioning reference signal, PRS; and the first periodicity is a periodicity of the SRS and the second periodicity is a periodicity of the PRS. In some embodiments, the association between the first periodicity and the second periodicity comprises at least one relation associated with the first periodicity and the second periodicity. In some embodiments, the at least one relation includes at least one of: a maximum of the first periodicity and the second periodicity; a minimum of the first periodicity and the second periodicity; and a difference between the first periodicity and the second periodicity. In some embodiments, the at least one relation includes at least one of: a mean of at least the first periodicity and the second periodicity; a least common multiple of at least the first periodicity and the second periodicity; and a modulus operation comprising the first periodicity and the second periodicity.

In some embodiments, the at least one relation depends on a condition. In some embodiments, a first relation is used when the condition is met; otherwise, a second relation is used. In some embodiments, the condition is based at least in part on a threshold value, the first relation being used when the threshold value is exceeded; otherwise, the second relation is used. In some embodiments, the condition is based further on a third relation, the first relation being used when the threshold value is exceeded by the third relation; otherwise, the second relation is used. In some embodiments, the measurement time is the function of the association between the first periodicity and the second periodicity when a condition is met; otherwise, the measurement time is not a function of the association. In some embodiments, the condition comprises a configured value, the measurement time is the function of the association when the configured value is met; otherwise, the measurement time is not a function of the association.

In some embodiments, the condition comprises a threshold value, the measurement time is the function of the association when the threshold value is exceeded; otherwise, the measurement time is not a function of the association. In some embodiments, the measurement time is further the function of at least one of a minimum duration for the measurement time and a scaling factor. In some embodiments, the measurement time is a maximum of the association and the at least one of the minimum duration for the measurement time and the scaling factor. In some embodiments, the measurement time is further the function of at least one of: a periodicity associated with an activity level of the WD, a measurement gap and a measurement gap periodicity. In some embodiments, performing the at least one RTT measurement further comprises performing, such as via one or more of processing circuitry <NUM>, processor <NUM> and radio interface <NUM>, multiple RTT measurements associated with multiple different nodes.

Having described the general process flow of arrangements of the disclosure and having provided examples of hardware and software arrangements for implementing the processes and functions of the disclosure, the sections below provide details and examples of arrangements for performing a round trip time measurement between two or more nodes or devices over a measurement time.

Some embodiments may provide for more accurate RTT measurements between two nodes or devices over Tm as compared with known arrangements.

In some embodiments, a round trip time (RTT) measurement performed by a first node (Node1) is a relation between two timing measurement components, a first component comprising measuring reception timing (TRX) of a signal received by Node1 from a second node (Node2) and a second component comprising measuring transmission timing (TTX) of a signal transmitted by Node1. In some embodiments, either Node1 or Node2 may be network node <NUM>. An example of the relation is the difference between TRX and TTX (e.g. TRX -TTX). RTT is also called as a bidirectional timing measurement. Examples of RTT measurements are WD RX-TX time difference measurements, network node or gNB RX-TX time difference measurements, timing advances, propagation delays etc..

The term multi-round trip (multi-RTT) measurement used herein corresponds to any WD <NUM> measurement comprising at least one RTT measurement on signals of one serving cell or TRP (e.g. PCell, PSCell, etc.) and at least one RTT measurement on signals of another cell or TRP (e.g. a neighbor cell, another serving cell etc.). Examples of multi-RTT measurement are multi-RTT positioning measurements such as multiple WD RX-TX time difference measurements involving two or more cells, timing advance, combination of or difference between two RTT measurements, etc..

One scenario involves at least one first node (Node1) and at least one second node (Node2). In some embodiments, either Nodel or Node2 may be network node <NUM>. Nodel is configured by a third node (Node3) to perform RTT measurement on signals operating between Node1 and Node2. The term operating a signal between nodes refers to one node transmitting the signal to another node and/or one node receiving the signal from another node. Examples of signals are reference signals, pilot signals etc. Node1 may be configured to transmit at least a first reference (RS1). Node2 may be configured to transmit at least a second reference (RS2). At least one of Node1 and Node2 may further be configured with low activity level, e.g., with DRX, DTX, and/or control channel monitoring pattern.

Node1 and Node2 can have different characteristics in different RTT measurement scenarios.

For example, in a first exemplary scenario, Nodel and Node2 are WD <NUM> and network node <NUM>, respectively. In this case, the RTT measurement is performed by WD <NUM> on reference signals operating between WD <NUM> and network node <NUM>. In one example, RS1 and RS2 are SRS and PRS respectively. This scenario is illustrated in <FIG>, scenario (A).

In a second exemplary scenario, Node1 and Node2 are network nodes (NNs) <NUM> and WD <NUM>, respectively. In this case, the RTT measurement is performed by network node <NUM> on reference signals operating between WD <NUM> and network node <NUM>. In one example RS1 and RS2 are PRS and SRS, respectively. This scenario is illustrated in <FIG>, scenario (B).

In a third exemplary scenario, Node1 and Node2 are WD 22a and WD 22b, respectively, and are capable of, i.e., configured to support, D2D operation (e.g. V2X, Prose etc.). In this case, the RTT measurement is performed by WD 22a on signals operating between WD 22a and WD 22b. In one example, RS1 and RS2 are SRS and SRS, respectively. In another example RS1 and RS2 are SRS and PRS, respectively. This scenario is illustrated in <FIG>, scenario (C).

<FIG> illustrates examples of Node1 performing an RTT measurement. In <FIG>, scenario (A) Nodel is WD <NUM>, Node2 is network node <NUM>, RS1 is SRS and RS2 is PRS. In <FIG>, scenario (B), Nodel is network node <NUM>, Node2 is WD <NUM>, RS1 is PRS and RS2 is SRS. In <FIG>, scenario (C), Nodel is WD 22a, Node2 is WD 22b, RS1 and RS2 can be any RS transmitted by WD22a and WD22b respectively, e.g. RS1 and RS2 are both SRS.

Node1 may also be configured to perform multi-RTT measurements on signals operating between Nodel and one or more Node2s (e.g. N21, N22,. In this case, Nodel may be a WD. RS<NUM> is a RS transmitted by Nodel to N2k (i.e. kth Node2). RS<NUM> is a RS transmitted by Node2k to Node1. As one case, Nodel may transmit the same RS regardless of the number of Node2s, i.e. R1= RS<NUM> = RS<NUM>,. ,= RS<NUM>. This arrangement is shown in <FIG>.

<FIG>, scenario (A) and <NUM>, scenario (B) illustrates examples of Node1 performing multi-RTT measurements. In <FIG>, scenario (A), Node1 is WD22, Node2s are network nodes <NUM>, RS<NUM> is SRS and RS<NUM> is PRS. In <FIG>, scenario (B), Nodel is WD 22a, Node2s are WD 22bs, RS<NUM> and RS<NUM> can be any RS transmitted by WD 22a and WD22b respectively, e.g. RS<NUM> and RS<NUM> are both SRS.

Node3 may or may not be different from Node1 and Node2. Node3 can for example be a SON/O&M node, a serving or other BS or TRP, positioning node, WD <NUM>, etc. Node3 may configure at least one of an RTT measurement to be performed by Node1, an RTT measurement to be performed by Node2, RS1 transmission and RS2 transmission.

Various embodiments are directed toward a method in network node <NUM> of performing an RTT measurement as function of RS1 and RS2 periods.

According to an aspect of an embodiment, network node <NUM> may perform at least one RTT measurement over a measurement time (Tm), which is function of at least an association between a periodicity (TRS1) of RS1 and a periodicity (TRS2) of RS2. This embodiment may be related to the arrangement shown in <FIG>.

The RTT measurement performed over Tm may comprise one or more measurement samples. For example, over Tm, multiple samples can be combined by network node <NUM> based on a function (e.g. mean) to achieve certain RTT measurement accuracy. The measurement sample may also be interchangeably called as sample, snapshot, measured value etc. Each sample may be a function of two timing measurement components.

In some embodiments, a first component may include reception timing (TRX) of RS2 received by Nodel, e.g. network node <NUM>, from Node2 and a second component may comprise transmission timing (TTX) of RS1 transmitted by Node1.

In one example each sample is the difference (ΔT) between TRX and TTX, e.g. <MAT>.

The measurement time, Tm, can be expressed by following generic expression: <MAT> where:.

In one example, TRS1 and TRS2 correspond to PRS resource periodicity (TperPRS) and SRS resource periodicity (TSRS), respectively, e.g. when Nodel is network node <NUM> and Node2 is WD <NUM>. In another example, TRS1 and TRS2 correspond to SRS resource periodicity (TSRS) and PRS resource periodicity (TperPRS), respectively, e.g., when Node1 is WD <NUM> and Node2 is network node <NUM>. In yet another example, TRS1 and TRS2 correspond to SRS resource periodicity (TSRS1) and SRS resource periodicity (TSRS2) respectively, e.g., when Nodel is WD 22a and Node2 is WD22b capable of D2D operation.

) associates TRS1 and TRS2 based on a relation. Examples of a relation are maximum, mean, maximum/minimum, ceil(maximum/minimum), least common multiple LCM(TRS1,TRS2), modulus, etc., of TRS1 and TRS2, or any function of these functions. The relation may also depend on a condition, e.g., a first relation applies when mod(max(TRS1,TRS2)/min(TRS1,TRS2)) exceeds a first threshold (e.g., <NUM> or <NUM>) otherwise a second relation applies.

One example of an expression defining Tm can be expressed as follows: <MAT>.

Another example of an expression defining Tm can be expressed as follows assuming α<NUM>(TRS1,TRS2) = MAX(TRS1,TRS2): <MAT>.

Examples of K<NUM> and K<NUM> are <NUM> and <NUM>, respectively, assuming TRS1 and TRS2 are also expressed in ms. In one case K<NUM> = <NUM> and K<NUM> = <NUM> (e.g. measurement is based on single sample).

According to another aspect of an embodiment, Node1, e.g. network node <NUM>, performs an RTT measurement on, RS1 transmitted to Node2 and RS2 received from Node2, over Tm, which is function of at least an association between TRS1, TRS2 and a measurement gap periodicity (TG) if measurement gaps are used by network node <NUM> for performing the RTT measurements. The measurement gap periodicity is also interchangeably called a measurement gap repetition period (MGRP), e.g. the period with which WD <NUM> is required to monitor a control channel e.g. PDCCH). For example, network node <NUM> may have to receive signals from Node2 outside the active bandwidth part of the serving cell of network node <NUM>, and therefore gaps are configured. An example of a measurement gap pattern comprises a periodic gap of <NUM> repeated with a periodicity of <NUM>. An example of a general expression defining Tm when gaps are used for RTT measurement can be expressed as follows: <MAT>.

Examples of α<NUM> are max, mean, maximum/minimum, ceil(maximum/minimum), least common multiple e.g. LCM(TRS1,TRS2, TG), modulus, etc., of TRS1 and TRS2 and TG, or any function of these functions. The relation may also depend on a condition, e.g., a first relation applies when mod(max(TRS1,TRS2)/min(TRS1,TRS2)) exceeds a first threshold (e.g., <NUM> or <NUM>) otherwise a second relation applies.

An example of an expression defining Tm can be expressed as follows assuming α<NUM>(TRS1,TRS2,TG) = MAX(TRS1,TRS2,TG): <MAT>.

According to a third aspect of the first embodiment the measurement time (Tm) is function of at least the association, α<NUM>(. ), between TRS1, TRS2, and periodicity (Tact) of WD <NUM> activity level. Examples of WD <NUM> activity levels include DRX, enhanced DRX (eDRX), a resource pattern for monitoring serving cell (e.g. control channel monitoring pattern) etc. Examples of periodicity include WD <NUM> DRX cycle length, eDRX cycle length, control channel monitoring periodicity (e.g., period with which the WD <NUM> is required to monitor a control channel e.g. PDCCH). An example of a general expression defining Tm when WD <NUM> is configured with a certain WD activity pattem (e.g. DRX, eDRX, etc.) can be expressed as follows: <MAT> where:.

Examples of α<NUM> are max, mean, maximum/minimum, ceil(maximum/minimum), least common multiple, e.g., LCM(TRS1,TRS2, Tact), modulus, etc., of TRS1 and TRS2 and Tact, or any function of these functions. The relation may also depend on a condition, e.g., a first relation applies when mod(max(TRS1,TRS2)/min(TRS1,TRS2)) exceeds a first threshold (e.g., <NUM> or <NUM>) otherwise a second relation applies.

An example of an expression defining Tm can be expressed as follows assuming α3(TRS1,TRS2,Tact) = MAX(TRS1,TRS2,Tact): <MAT>.

According to a fourth aspect of the first embodiment, the measurement time (Tm) is function of at least the association, α<NUM>(. ), between TRS1, TRS2, TG (if WD <NUM> is configured with gaps) and Tact (if WD <NUM> is configured with the WD <NUM> activity level). An example of a general expression defining Tm when WD <NUM> is configured with gaps and also with a certain WD <NUM> activity pattern (e.g. DRX, eDRX etc.) can be expressed as follows: <MAT>.

An example of an expression defining Tm can be expressed as follows assuming α<NUM>(TRS1,TRS2, TG, Tact) = MAX(TRS1,TRS2, TG, Tact): <MAT> where:.

Examples of α<NUM> are max, mean, maximum/minimum, ceil(maximum/minimum), least common multiple e.g. LCM(TRS1,TRS2, TG, Tact), modulus, etc., of TRS1 and TRS2 and TG and Tact, or any function of these functions. The relation may also depend on a condition, e.g., a first relation applies when mod(max(TRS1,TRS2)/min(TRS1,TRS2)) exceed a first threshold (e.g., <NUM> or <NUM>) otherwise a second relation applies.

According to a fifth aspect of the first embodiment, the measurement time (Tm) is function of any association between TRS1 and TRS2, provided TRS1 and/or TRS2 meet one or more criteria. If the one or more criteria are not met then Tm is not function of any of the associations α<NUM>(. ), α<NUM>(. ), α<NUM>(. ) or α<NUM>(. Examples of criteria include:.

In one example Tm is a function of α<NUM>(. ) as in expressions (<NUM>, <NUM> or <NUM>) provided that TRS1 is larger than certain threshold (H<NUM>) and/or TRS2 is larger than certain threshold (H<NUM>). Otherwise Tm is not function of α<NUM>(. ), e.g., Tm = Kc; where Kc is a fixed value such as <NUM>.

In another example, if Tact is larger than TRS1 by certain margin (H<NUM>) and/or TRS2 is larger than certain threshold (H<NUM>) then Tm is not a function of any association between TRS1 and TRS2; but Tm may be function of Tact. Otherwise Tm is a function of an association between at least TRS1 and TRS2 as in expressions (<NUM>,<NUM>,<NUM> or <NUM> herein).

Network node <NUM> uses the results of the performed RTT measurement for one or more operational tasks. The measurement results may comprise, e.g., a measurement value, associated identity of Node2 (e.g. cell ID, beam ID, resource ID, resource set ID, PRS resource ID, PRS resource ID etc.), etc. Examples of tasks are:
Reporting one or more of the measurement results to one or more nodes, e.g. to a network node such as a base station, positioning node, or another WD <NUM>, etc. Using the results for one or more internal procedures in the WD <NUM>. Examples of such procedures are determining the WD <NUM> location, determining WD <NUM> timing with respect to another node, adapting the WD <NUM> timing, etc. Logging one or more measurement results for future use, e.g., for MDT, SON, positioning, collecting performance statistics.

Embodiments may be directed toward a method in network node <NUM> of performing multi-RTT measurement as function of RS1 and RS2 periods on multiple cells.

In a scenario related to another embodiment, network node <NUM> is configured to perform the RTT measurement over the measurement time (Tm) on multiple nodes in multi-RTT measurement scenario. This type of RTT measurement is called herein as multi-RTT measurement. More specifically network node <NUM> is configured to performed RTT measurement on signals operating between network node <NUM> and a set of 'k' different Node2s (Node21, Node22,. , Node2k); where k><NUM>. This embodiment is related to the arrangement shown in <FIG>.

According to a basic concept of the second embodiment, Nodel, e.g., network node <NUM>, is configured to perform multi-RTT measurement over the measurement time (Tm), which is function of at least an association between a set S1 = {TRS11, TRS12,. ,TRS1k} comprising periodicities of RSs transmitted by Nodel towards Node2s and a set S2 = {TRS21, TRS11,. ,TRS2k} comprising periodicities of RSs transmitted by Node2s towards Node1. For example, TRS11 is a periodicity of reference signal (RS<NUM>) transmitted by Node1 towards Node21, TRS12 is a periodicity of reference signal (RS<NUM>) transmitted by Node1 towards Node22, and TRS1k is a periodicity of reference signal (RS<NUM>) transmitted by Node1 towards Node2k. Similarly, as an example, TRS21 is a periodicity of reference signal (RS<NUM>) transmitted by Node2 towards Node1, TRS22 is a periodicity of reference signal (RS<NUM>) transmitted by Node22 towards Node1, and TRS2k is a periodicity of reference signal (RS<NUM>) transmitted by Node2k towards Nodel.

As part of the multi-RTT measurement procedure, network node <NUM> may perform a set of k different RTT measurements over the measurement time, Tm. For example, the RTT measurement (RTTk) performed by Node1 on signals operating between Node1 and Node1k may comprise one or more measurement samples. Each measurement sample may comprise two timing measurement components as described herein. For example, each sample of the RTTk is function of two timing measurement components:.

According to an aspect of a second embodiment, Nodel, e.g., network node <NUM>, performs the multi-RTT measurement on k different Node2s without any measurement gaps. For example, the signals in set S1 and set S2 are transmitted and received by Node1 respectively in active bandwidth part of the serving cell of Node1. In this case the measurement time, Tm, for performing multi-RTT measurement on k different Node2s, can be expressed by the following generic expression: <MAT> where:.

In one example, set S1={TRS11, TRS12,. ,TRS1k} corresponds to SRS resource periodicities (TSRS) and set S2={TRS21, TRS22,. ,TRS2k} corresponds to PRS resource periodicities (TperPRS) respectively, e.g. when Nodel is WD <NUM> and Node21,. ,Node2k are BSs such as network node <NUM>. In another example, both set S1={TRS11, TRS12,. ,TRS1k} and set S2={TRS21, TRS22,. ,TRS2k} correspond to SRS resource periodicities, {TSRS11, TSRS12,. ,TSRS1k} and {TSRS21, TSRS22,. ,TSRS2k}, respectively, e.g., when Node1 is WD 22a and Node21,. ,Node2k are WDs capable of D2D operation.

) associates set S1 and set S2 based on a relation. Examples of relation are maximum, mean, maximum/minimum, ceil(maximum/minimum), least common multiple e.g. LCM(S1,S2), modulus, etc., of sets S1 and S2, or any function of these functions. The relation may also depend on a condition, e.g., a first relation applies when mod(max(S1,S2)/min(S1,S2)) exceeds a first threshold (e.g., <NUM> or <NUM>) otherwise a second relation applies.

An example of the measurement time, Tm, for performing multi-RTT measurement on k different Node2s, can be expressed by the following specific expression: <MAT>.

In general, periodicities of the RS transmitted by Node1 towards Node2s can be different. In another example, the periodicities of the RS transmitted by Node1, e.g., network node <NUM>, towards some of the Node2s can be the same while towards the other Node2s can be different.

As one case, Node1 may transmit the same RS (e.g., SRS) towards all Node2s. In one example the periodicity of the RS transmitted by Node1 toward all Node2s is also the same. This can especially be the case when multi-RTT measurements are performed on k number of cells operating on the same frequency layer, e.g. RTT measurements done on a serving cell and one or more neighbor cells on the same frequency layer such as the serving layer. In this case: TRS11 =TRS12=,. ,=TRS1k = TRS1. The corresponding measurement time, Tm, may be expressed by the following expression: <MAT>.

According to a second aspect of the second embodiment, Nodel, e.g., network node <NUM>, performs the multi-RTT measurement on k different Node2s using measurement gaps. For example, Nodel may have to receive the signals in set S2 from Node2s during the measurement gaps. In this case, the measurement time, Tm, for performing multi-RTT measurement on k different Node2, can be expressed by the following generic expression: <MAT> where:.

An example of the measurement time, Tm, for performing multi-RTT measurement on k different Node2s when the measurement is done in gaps, can be expressed by the following specific expression: <MAT>.

Also, in an exemplary case, Node1 may transmit the same RS (e.g. SRS) towards all Node2s and therefore TRS11 =TRS12=,. ,=TRS1k = TRS1. In this case the corresponding measurement time, Tm, is expressed by the following expression: <MAT>.

According to a third aspect of the second embodiment, Node1 performs the multi-RTT measurement on k different Node2s when configured with WD <NUM> activity level e.g. DRX cycle, eDRX cycle etc. For example, to save power the Node1 may transmit and/or receive signals in set S1 and set S2 as function of DRX cycle as well as periodicities of signals in set S1 and set S2. In this case the measurement time, Tm, for performing multi-RTT measurement on k different Node2, can be expressed by the following generic expression: <MAT> where:.

An example of the measurement time, Tm, for performing multi-RTT measurement on k different Node2s when the measurement is done in DRX, can be expressed by the following specific expression: <MAT>.

Also, as one case, Node1 may transmit the same RS (e.g. SRS) towards all Node2s and therefore TRS11 =TRS12=,. ,=TRS1k = TRS1. In this case, the corresponding measurement time, Tm, may be expressed by the following expression: <MAT>.

According to a fourth aspect of the second embodiment, Node1 performs the multi-RTT measurement on k different Node2s using measurement gaps, and may also be configured with WD <NUM> activity level, e.g., DRX cycle, eDRX cycle, etc. For example, to save power, the network node <NUM> may transmit and/or receive signals in set S1 and set S2 as function of DRX cycle as well as periodicities of signals in set S1 and set S2 and the measurement gap periodicity. In this case, the measurement time, Tm, for performing multi-RTT measurement on k different Node2, can be expressed by the following generic expression: <MAT> where:.

An example of the measurement time, Tm, for performing multi-RTT measurement on k different Node2s when the measurement is done in DRX and using gaps, can be expressed by the following specific expression: <MAT>.

Also, in one case, Node1 transmits the same RS (e.g. SRS) towards all Node2s and therefore TRS11 =TRS12=,. ,=TRS1k = TRS1. In this case, the corresponding measurement time, Tm, may be expressed by the following expression: <MAT>.

According to a fifth aspect of the second embodiment, the measurement time (Tm) is function of any association between set S1 and set S2, provided set S1 and/or set S2 meet one or more criteria. If the one or more criteria are not met, then Tm is not function of any of the associations β<NUM>(. ), β<NUM>(. ), β<NUM>(. ) or β<NUM>(. Examples of criteria include:.

In one example, Tm is a function of β<NUM>(. ) as in expressions (<NUM>, <NUM> or <NUM>) provided that at least one periodicity of the RS in set S1 is larger than a certain threshold (G11) and/or at least one periodicity of the RS in set S2 is larger than a certain threshold (G12). Otherwise Tm is not function of β<NUM>(. ) e.g. Tm = Kd; where Kd is a fixed value such as <NUM>.

In another example, if Tact is larger than at least one periodicity of the RS in set S1 by certain margin (G21) and/or at least one periodicity of the RS in set S2 is larger than certain threshold (G22), then Tm is not a function of any association between set S1 and set S2; but Tm may be function of Tact. Otherwise, Tm is a function of an association between at least set S1 and set S2 as in expressions (<NUM>-<NUM>).

The network node <NUM> may use the results of the performed multi-RTT measurement for one or more operational tasks. The measurement results may include, e.g., measurement values, associated identities of Node2s (e.g. cell IDs), etc. Examples of tasks may be similar to those described with respect to the previous embodiments.

Some embodiments may include one or more of the following:.

Embodiment A1. A network node configured to communicate with at least one of a second network node and a wireless device (WD), the network node configured to, and/or comprising a radio interface and/or comprising processing circuitry configured to:
perform at least one round trip time (RTT) measurement over a measurement time (Tm), the at least one RTT measurement being a function of at least an association between a periodicity (TRS1) of a first reference signal (RS1) transmitted from the network node to the at least one of a second network node and a WD and a periodicity (TRS2) of a second reference signal (RS2) transmitted from the at least one of a second network node and a WD to the network node.

Embodiment A2. The network node of Embodiment A1, wherein RS1 further comprises a sounding reference signal (SRS) and RS2 further comprises a positioning reference signal (PRS).

Embodiment A3. The network node of Embodiment A1, wherein RS1 further comprises a positioning reference signal (PRS) and the RS2 further comprises a sounding reference signal (SRS).

Embodiment A4. The network node of any one of Embodiments A1-A3, wherein Tm is further a function of at least one of the periodicity of the WD's activity level and a measurement gap.

Embodiment A5. The network node of any one of Embodiments A1-A4, wherein RS1 is specific to the WD.

Embodiment A6. The network node of any one of Embodiments A1-A5, wherein the processing circuitry is further configured to transmit RS1 based on a timing advance with respect to the at least one of a second network node and a WD.

Embodiment A7. The network node of any one of Embodiments A1-A6, wherein the network node and/or the radio interface and/or the processing circuitry is further configured to perform an RTT measurement over Tm between the network node and a plurality of other nodes.

Embodiment A8. The network node of Embodiment A7, wherein the network node and/or the radio interface and/or the processing circuitry is further configured to one or more of:.

Embodiment B1. A method implemented in a network node, the method comprising: performing at least one round trip time (RTT) measurement over a measurement time (Tm), the at least one RTT measurement being a function of at least an association between a periodicity (TRS1) of a first reference signal (RS1) transmitted from the network node to at least one of a second network node and a wireless device (WD) and a periodicity (TRS2) of a second reference signal (RS2) transmitted from the at least one of a second network node and a WD to the network node.

Embodiment B2. The method of Embodiment B1, wherein RS1 further comprises a sounding reference signal (SRS) and RS2 further comprises a positioning reference signal (PRS).

Embodiment B3. The method of Embodiment B1, wherein RS1 further comprises a positioning reference signal (PRS) and the RS2 further comprises a sounding reference signal (SRS).

Embodiment B4. The method of any one of Embodiments B1-B3, wherein Tm is further a function of at least one of the periodicity of a WD's activity level and a measurement gap.

Embodiment B5. The method of any one of Embodiments B1-B4, wherein RS1 is specific to a WD.

Embodiment B6. The method of any one of Embodiments B1-B5, further comprising transmitting RS1 based on a timing advance with respect to the at least one of a second network node and a WD.

Embodiment B7. The method of any one of Embodiments B1-B6, further comprising performing an RTT measurement over Tm between the network node and a plurality of other nodes.

Embodiment B8. The method of Embodiment B7, further comprising one or more of:.

Embodiment C1. A wireless device (WD) configured to communicate with at least one of a network node and a second WD, the WD configured to, and/or comprising a radio interface and/or processing circuitry configured to:
perform at least one round trip time (RTT) measurement over a measurement time (Tm), the at least one RTT measurement being a function of at least an association between a periodicity (TRS1) of a first reference signal (RS1) transmitted from the WD to the at least one of a network node and a second WD and a periodicity (TRS2) of a second reference signal (RS2) transmitted from the at least one of a network node and a second WD to the WD.

Embodiment C2. The WD of Embodiment C1, wherein RS1 further comprises a sounding reference signal (SRS) and RS2 further comprises a positioning reference signal (PRS).

Embodiment C3. The WD of Embodiment C1, wherein RS1 further comprises a positioning reference signal (PRS) and the RS2 further comprises a sounding reference signal (SRS).

Embodiment C4. The WD of any one of Embodiments C1-C3, wherein Tm is further a function of at least one of the periodicity of the WD's activity level and a measurement gap.

Embodiment C5. The WD of any one of Embodiments C1-C4, wherein RS1 is specific to the WD.

Embodiment C6. The WD of any one of Embodiments C1-C5, wherein the WD and/or the radio interface and/or the processing circuitry is further configured to transmit RS1 based on a timing advance with respect to the at least one of a network node and a second WD.

Embodiment C7. The WD of any one of Embodiments C1-C6, wherein the WD and/or the radio interface and/or the processing circuitry is further configured to perform an RTT measurement over Tm between the WD and a plurality of other nodes.

Embodiment C8. The WD of Embodiment C7, wherein the WD and/or the radio interface and/or the processing circuitry is further configured to one or more of:.

Embodiment D1. A method implemented in a wireless device (WD), the method comprising:
performing at least one round trip time (RTT) measurement over a measurement time (Tm), the at least one RTT measurement being a function of at least an association between a periodicity (TRS1) of a first reference signal (RS1) transmitted from the WD to at least one of a network node and a second WD and a periodicity (TRS2) of a second reference signal (RS2) transmitted from the at least one of a network node and a second WD to the WD.

Embodiment D2. The method of Embodiment D1, wherein RS1 further comprises a sounding reference signal (SRS) and RS2 further comprises a positioning reference signal (PRS).

Embodiment D3. The method of Embodiment D1, wherein RS1 further comprises a positioning reference signal (PRS) and the RS2 further comprises a sounding reference signal (SRS).

Embodiment D4. The method of any one of Embodiments D1-D3, wherein Tm is further a function of at least one of the periodicity of the WD's activity level and a measurement gap.

Embodiment D5. The method of any one of Embodiments D1-D4, wherein RS1 is specific to the WD.

Embodiment D6. The method of any one of Embodiments D1-D5 further comprising transmitting RS1 based on a timing advance with respect to the at least one of a network node and a second WD.

Embodiment D7. The method of any one of Embodiments D1-D6, further comprising performing an RTT measurement over Tm between the WD and a plurality of other nodes.

Embodiment D8. The method of Embodiment D7, further comprising one or more of:.

Claim 1:
A method implemented in a wireless device the method comprising:
performing (<NUM>) at least one round trip time, RTT, measurement over a measurement time, Tm, the measurement time being a function of at least an association between a first periodicity, TRS1, of a first reference signal and a second periodicity, TRS2, of a second reference signal, the first reference signal being transmitted from the wireless device to a network node and the second reference signal being received by the wireless device from the network node; and
using (<NUM>) a result of the at least one RTT measurement for one or more operational tasks, wherein:
the first reference signal is a sounding reference signal, SRS, and the second reference signal is a positioning reference signal, PRS; and
the first periodicity is a periodicity of the SRS and the second periodicity is a periodicity of the PRS.