Locating terminal device using radio link with reference device

Abstract

A terminal device comprising means for: positioning the terminal device using a radio link with at least one reference device in a first positioning session; detecting a degradation in radio link quality of a radio link between the terminal device and the reference device; in accordance with the detected degradation of the radio link quality of the radio link between the terminal device and the reference device, positioning assistance information is transmitted to at least another terminal device via sidechain communication, where the positioning assistance information indicates at least the degradation of the radio link quality of the radio link between the terminal device and the reference device.

Description

Technical Field

[0001] Examples of the present disclosure relate to locating a terminal device using a radio link with a reference device. Background Art

[0002] It is desirable to be able to locate the terminal device. This can be achieved at least by using a radio link with a reference device.

[0003] Different positioning algorithms can be used. Examples include time difference of arrival (TDOA), round trip time (RTT), angle of arrival / departure (AOA / D), etc.

[0004] For example, the positioning algorithm may use multiple distances to reference points (multilateration). For example, the positioning algorithm may use multiple angles to reference points (multi-bearing). For example, the positioning algorithm may use angles and distances to one or more reference points.

[0005] Positioning the terminal device may, for example, include determining a relative position, such as relative to a reference device. Positioning the terminal device may, for example, include determining an absolute position. For example, providing 2D / 3D geographic coordinates (e.g., latitude, longitude, altitude) within a coordinate system. Positioning the terminal device may, for example, include ranging, such as relative to a reference device. For example, the distance to the reference device.

[0006] The positioning of the terminal device 10 can be used, for example, in Internet of Vehicles, public safety, industrial machinery positioning, industrial Internet of Things, etc.

[0007] It is desirable to improve the positioning of terminal devices. Summary of the invention

[0008] According to various but not necessarily all examples, there is provided a terminal device including means for:

[0009] locating the terminal device using a radio link with at least one reference device in a first positioning session;

[0010] detecting a degradation of a radio link quality of a radio link between the terminal device and the reference device;

[0011] sending positioning assistance information to at least one further terminal device via a sidelink communication in response to a detected degradation in radio link quality of a radio link between the terminal device and the reference device,

[0012] The positioning assistance information at least indicates a degradation of a radio link quality of a radio link between the terminal device and the reference device.

[0013] In some, but not necessarily all, examples, the radio link comprises receiving a radio positioning reference signal sent from the reference device to the terminal device and / or comprises sending a radio positioning reference signal from the terminal device to the reference device.

[0014] In some but not necessarily all examples, the radio positioning reference signal is a sidelink positioning reference signal.

[0015] In some but not necessarily all examples, the terminal device is a target to be positioned and the reference device is an anchor point supporting positioning of the terminal device in a first positioning session in a first sidelink network, wherein another terminal device is a target to be positioned and the reference device is an anchor point supporting positioning of the other terminal device in a second positioning session between the other terminal device and the reference device in a second sidelink network.

[0016] In some but not necessarily all examples, the reference device is a network node and the radio positioning reference signal is a downlink positioning reference signal sent from the reference device to the terminal device and / or the radio positioning reference signal is an uplink positioning reference signal sent from the terminal device to the reference device.

[0017] In some but not necessarily all examples, the means for detecting degradation of the radio link quality between the terminal device and the reference device comprises means for detecting a radio link failure or means for predicting a radio link failure based on measurements of the radio link quality over time.

[0018] In some but not necessarily all examples, the apparatus comprises means for determining positioning assistance information based at least on a detected degradation of a radio link quality of a radio link between the terminal apparatus and a reference apparatus.

[0019] In some but not necessarily all examples, the positioning assistance information identifies at least one of the following:

[0020] an identifier of the reference device;

[0021] the location of the reference device;

[0022] the location of the terminal device;

[0023] The mobility pattern of the terminal device;

[0024] The location service level of the location session;

[0025] The time and frequency resources of the radio positioning reference signal transmitted over the radio link;

[0026] a cause of degradation of the radio link quality of the radio link between the terminal device and the reference device;

[0027] the duration of the degradation of the radio link quality of the radio link between the terminal device and the reference device; or

[0028] information associated with an alternative reference device for locating another terminal device in a second positioning session;

[0029] In some but not necessarily all examples, the device includes a component for sending an interruption notification capability to another terminal device via sidelink communication before sending positioning assistance information to the other terminal device via sidelink communication, wherein the interruption notification capability indicates the ability of the terminal device to provide positioning assistance information.

[0030] In some but not necessarily all examples, the apparatus includes means for receiving an interruption notification request from another terminal apparatus via sidelink communication before sending positioning assistance information to the other terminal apparatus via sidelink communication, wherein the positioning assistance information is determined based at least on the interruption notification request.

[0031] In some but not necessarily all examples, the interrupt notification request includes at least one of the following:

[0032] a reference device identifier for locating another terminal device in a second positioning session;

[0033] the mobility pattern of another terminal device; or

[0034] Conditions for sending positioning assistance information.

[0035] In some but not necessarily all examples, the apparatus is configured as a user equipment comprising a radio transceiver for communicating with a cell node of a radio access network, wherein sidelink communication is performed between the user equipment and other user equipment without using the radio access network.

[0036] According to various but not necessarily all examples, there is provided a computer program which, when executed on a computer of a terminal device, performs:

[0037] locating the terminal device using a radio link with at least one reference device in a first positioning session;

[0038] detecting a degradation of a radio link quality of a radio link between the terminal device and the reference device;

[0039] causing, based on a detected degradation in radio link quality of a radio link between the terminal device and the reference device, sending positioning assistance information to at least another terminal device via a sidelink communication,

[0040] The positioning assistance information at least indicates a degradation of a radio link quality of a radio link between the terminal device and the reference device.

[0041] According to various but not necessarily all examples, there is provided a method performed on a terminal device, comprising:

[0042] locating the terminal device using a radio link with at least one reference device in a first positioning session;

[0043] detecting a degradation of a radio link quality of a radio link between the terminal device and the reference device;

[0044] sending positioning assistance information to at least one further terminal device via a sidelink communication in response to a detected degradation in radio link quality of a radio link between the terminal device and the reference device,

[0045] The positioning assistance information at least indicates a degradation of a radio link quality of a radio link between the terminal device and the reference device.

[0046] According to various but not necessarily all examples, there is provided a terminal device including means for:

[0047] locating the terminal device using a radio link with at least a first reference device in a second positioning session;

[0048] receiving positioning assistance information from another terminal device via sidelink communication, wherein the positioning assistance information at least indicates a degradation of a radio link quality of a radio link between the other terminal device and a second reference device; and

[0049] According to the received positioning assistance information, when it is predicted that the quality of the radio link between the terminal device and the first reference device is degraded, it is determined to perform a preemption action.

[0050] In some but not necessarily all examples, the radio link comprises receiving a radio positioning reference signal sent from the first reference device to the terminal device and / or comprises sending a radio positioning reference signal from the terminal device to the first reference device.

[0051] In some but not necessarily all examples, the radio positioning reference signal is a sidelink positioning reference signal.

[0052] In some but not necessarily all examples, the terminal device is a target to be positioned and the first reference device is an anchor point supporting positioning of the terminal device in a second positioning session in a second sidelink network, wherein another terminal device is a target to be positioned and the second reference device is an anchor point supporting positioning of the other terminal device in a first positioning session between the other terminal device in the first sidelink network and the second reference device.

[0053] In some but not necessarily all examples, the apparatus includes means for performing a preemption action, including means for modifying the second positioning session and / or means for terminating the second positioning session.

[0054] In some but not necessarily all examples, the apparatus includes means for sending an interrupt notification request to another terminal apparatus via sidelink communication, requesting the other terminal apparatus to provide positioning assistance information.

[0055] In some but not necessarily all examples, the interrupt notification request includes at least one of the following:

[0056] an identifier of a first reference device for locating the terminal device in a second positioning session;

[0057] the mobility pattern of the terminal device; or

[0058] Conditions for sending positioning assistance information.

[0059] In some but not necessarily all examples, the positioning assistance information identifies at least one of the following:

[0060] an identifier of the second reference device;

[0061] the position of the second reference device;

[0062] the location of the other terminal device;

[0063] a mobility pattern of another terminal device;

[0064] a positioning service level for a first positioning session for locating another terminal device;

[0065] time-frequency resources of a radio positioning reference signal communicated in the first positioning session over a radio link between the other terminal device and the second reference device;

[0066] a cause of degradation of the radio link quality of the radio link between the other terminal device and the second reference device;

[0067] the duration of the degradation of the radio link quality of the radio link between the other terminal device and the second reference device; or

[0068] Information associated with an alternative reference device for locating the terminal device in a second positioning session.

[0069] In some but not necessarily all examples, the terminal device includes a component for receiving an interruption notification capability from another terminal device via sidelink communication before sending an interruption notification request to the other terminal device via sidelink communication, wherein the interruption notification capability indicates the ability of the other terminal device to provide positioning assistance information.

[0070] In some but not necessarily all examples, the first reference terminal device is the second reference terminal device.

[0071] According to various but not necessarily all examples, there is provided a computer program which, when executed on a computer of a terminal device, performs:

[0072] locating the terminal device using a radio link with at least a first reference device in a second positioning session;

[0073] causing receiving positioning assistance information from another terminal device via sidelink communication, wherein the positioning assistance information indicates at least a degradation of a radio link quality of a radio link between the other terminal device and a second reference device;

[0074] According to the received positioning assistance information, when it is predicted that the quality of the radio link between the terminal device and the first reference device is degraded, it is determined to perform a preemption action.

[0075] According to various but not necessarily all examples, there is provided a method performed on a terminal device, comprising:

[0076] locating the terminal device using a radio link with at least a first reference device in a second positioning session;

[0077] receiving positioning assistance information from another terminal device via sidelink communication, wherein the positioning assistance information at least indicates a degradation of a radio link quality of a radio link between the other terminal device and a second reference device;

[0078] According to the received positioning assistance information, when it is predicted that the quality of the radio link between the terminal device and the first reference device is degraded, it is determined to perform a preemption action.

[0079] Examples are provided as claimed in the following claims according to various but not necessarily all examples.

[0080] Although the examples and optional features of the above disclosure are described separately, it should be understood that they are provided in all possible combinations and arrangements and are included in the disclosure. It should be understood that various examples of the disclosure may include any or all of the features described for other examples of the disclosure, and vice versa. In addition, it should be understood that any one or more or all of the features, in any combination, can be implemented / included in / executable by devices, methods and / or computer program instructions as needed and appropriate. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] Some examples will now be described with reference to the accompanying drawings, in which:

[0082] Figure 1 An example of the subject matter described herein is shown;

[0083] Figure 2 Another example of the subject matter described herein is shown;

[0084] Figure 3 Another example of the subject matter described herein is shown;

[0085] Figure 4 Another example of the subject matter described herein is shown;

[0086] Figure 5 Another example of the subject matter described herein is shown;

[0087] Figure 6 Another example of the subject matter described herein is shown;

[0088] Figure 7 Another example of the subject matter described herein is shown;

[0089] Figure 8 Another example of the subject matter described herein is shown;

[0090] Fig. 9 Another example of the subject matter described herein is shown.

[0091] The drawings are not necessarily drawn to scale. For clarity and conciseness, certain features and views in the drawings may be shown schematically or exaggerated in scale. For example, to aid in illustration, the dimensions of certain elements in the drawings may be exaggerated relative to other elements. Similar reference numerals are used in the drawings to indicate similar features. For clarity, not all reference numerals may be shown in all drawings. DETAILED DESCRIPTION

[0092] Figure 1 One example of a system including a terminal device 10 , a reference device 100 , and another terminal device 200 is shown.

[0093] There is a side chain communication 30 from the terminal device 10 to another terminal device 200 .

[0094] There is a radio link 102 between the terminal device 10 and the reference device 100 .

[0095] The radio link 102 is used to locate the terminal device 10 during a positioning session.

[0096] Different positioning algorithms can be used. Examples include time difference of arrival (TDOA), round trip time (RTT), angle of arrival / departure (AOA / D), etc.

[0097] For example, the positioning algorithm may use multiple distances to reference points (multilateration). For example, the positioning algorithm may use multiple angles to reference points (multi-bearing). For example, the positioning algorithm may use angles and distances to one or more reference points.

[0098] Positioning the terminal device may, for example, include determining a relative position (eg, relative to a reference device).

[0099] Positioning the terminal device may include, for example, determining an absolute position, for example, providing 2D / 3D geographic coordinates (eg, latitude, longitude, altitude) within a coordinate system.

[0100] Positioning the terminal device may include, for example, ranging, such as ranging relative to a reference device, for example, the distance to the reference device.

[0101] The positioning of the terminal device 10 can be used, for example, in Internet of Vehicles, public safety, industrial machinery positioning, industrial Internet of Things, etc.

[0102] The radio link 102 may be a unidirectional link from or to the terminal device 10 , or may be a bidirectional link to and from the terminal device 10 .

[0103] In at least some examples, radio link 102 includes receiving a radio positioning reference signal sent from reference device 100 to terminal device 10 and / or includes sending a radio positioning reference signal from terminal device 10 to reference device 100 .

[0104] In one example, the reference device 100 is a network node, and the radio positioning reference signal is a downlink positioning reference signal sent from the reference device 100 to the terminal device 10 and / or the radio positioning reference signal is an uplink positioning reference signal sent from the terminal device 10 to the reference device 100. The network node may be, for example, a transmit-receive point (TRP) or a base station (e.g., a gNB).

[0105] In another example, the radio positioning reference signal is a sidelink positioning reference signal. In this example, the reference device 100 is a user equipment. The sidelink positioning reference signal can be sent in any appropriate channel. The sidelink positioning reference signal can be sent in a new physical sidelink channel or in an existing channel, such as a physical sidelink shared channel (PSSCH) or a physical sidelink feedback channel (PSFCH).

[0106] The terminal device 10 is a target to be positioned, and the reference device 100 is an anchor point that supports positioning the terminal device 10 in a positioning session in the sidelink network.

[0107] Although only a single radio link 102 with one reference device 100 is shown. In other examples (not shown), there may be multiple radio links 102 with multiple corresponding reference devices 100.

[0108] In some examples, the plurality of radio links 102 include only sidelink communications. In some examples, the plurality of radio links 102 include only radio access network communications (uplink / downlink). In some examples, the plurality of radio links 102 include a mix of sidelink communications and radio access network communications (uplink / downlink).

[0109] In some examples, the terminal device 10 includes a radio transceiver for communicating with a radio access network node (not shown), and the terminal device 200 includes a radio transceiver for communicating with a radio access network node. The sidelink communication 30 includes transferring information between the terminal devices 10, 200 without using a radio access network. The sidelink communication 30 uses a direct radio link between the terminal devices 10, 200 to transfer information between the terminal devices 10, 200 without using a radio access network.

[0110] In some examples, the terminal device 10 is configured as a user equipment including a radio transceiver for communicating with a cell node of a radio access network, and the terminal device 200 is configured as a user equipment including a radio transceiver for communicating with a cell node of the radio access network. The sidelink communication 30 is performed between the user equipment 10 and the user equipment 200 without using a radio access network.

[0111] In some but not necessarily all examples, the sidechain communication 30 uses:

[0112] Frequency resources of the radio access network, e.g., FR1, FR2; and / or

[0113] The frame structure of the radio access network, for example, a 10 ms radio frame is divided into 10 subframes; and / or

[0114] modulation of the radio access network, e.g. OFDM modulation with cyclic prefix; and / or

[0115] Flexible OFDM parameter sets for the radio access network, e.g., each OFDM parameter set is defined by a subcarrier spacing (SCS) and a cyclic prefix of an OFDM waveform. The SCS may be, for example, equal to 15kHz, 30kHz, 60kHz, or 120KHz. In some examples, at lower frequencies (e.g., FR1), the SCS supports 15kHz, 30kHz, and 60kHz, while at higher frequencies (e.g., FR2), the SCS supports 60kHz and 120kHz. A larger SCS results in a shorter slot duration

[0116] In some but not necessarily all examples, sidelink resource allocation and link adaptation are performed by the user equipment (rather than the radio access network).

[0117] In some but not necessarily all examples, the sidechain range is hundreds of meters.

[0118] In some but not necessarily all examples, the sidelink communication supports hybrid automatic repeat request (HARQ).

[0119] In some but not necessarily all examples, the sidelink communications support beamforming.

[0120] In some but not necessarily all examples, the sidelink-specific channel includes:

[0121] 1) Physical Sidelink Control Channel (PSCCH): carries control information in the sidelink.

[0122] 2) Physical Sidelink Shared Channel (PSSCH): carries data payload and additional control information in the sidelink.

[0123] 3) Physical Sidelink Broadcast Channel (PSBCH): carries information used to support sidelink synchronization. PSBCH is sent within the Sidelink Synchronization Signal Block (S-SSB).

[0124] 4) Physical Sidelink Feedback Channel (PSFCH): carries feedback related to successful or failed reception of sidelink transmissions.

[0125] A demodulation reference signal (DMRS) that a receiver uses to decode an associated sidelink physical channel (ie, PSCCH, PSSCH, PSBCH) is transmitted within the associated sidelink physical channel.

[0126] The Sidelink Channel State Information Reference Signal (SL CSI-RS) is used to measure the channel state information (CSI) at the receiver and then feed it back to the transmitter. The transmitter can adjust its transmission based on the fed-back CSI.

[0127] The Sidelink Phase Tracking Reference Signal (SL PT-RS) is used to mitigate the effects of phase noise due to oscillator imperfections, especially at higher frequencies. The SL PT-RS is transmitted within the PSSCH region of a slot.

[0128] like Figure 2 (as well as Figure 3 and Figure 4 ), the terminal device 10 includes components for the following operations:

[0129] positioning 112 a terminal device 10 using a radio link 102 with at least one reference device 100 in a first positioning session 110 ;

[0130] detecting 40 a degradation of a radio link quality of a radio link 102 between the terminal device 10 and the reference device 100;

[0131] sending 12 positioning assistance information 20 to at least another terminal device 200 via a sidelink communication 30 in response to a detected degradation of a radio link quality of a radio link 102 between the terminal device 10 and a reference device 100,

[0132] The positioning assistance information 20 at least indicates degradation of the radio link quality of the radio link between the terminal device 10 and the reference device 100 .

[0133] The above article targets Figure 1 The description provided of a positioning session with a reference device 100 using a radio link 102 is also related to Figure 2 (as well as Figure 3 and Figure 4 ) is related to a positioning session 110 with at least one reference device 100 using a radio link 102 .

[0134] In the example shown, the terminal device 10 is configured as a user equipment and includes a radio transceiver (not shown) for communicating with a cell node of a radio access network (not shown). The sidelink communication 30 is performed between the user equipment 10 and other user equipment (terminal device 200) without using a radio access network. In at least some examples, the sidelink communication 30 includes a data payload that includes the positioning assistance information 20.

[0135] In some but not necessarily all examples, the means 40 for detecting degradation of radio link quality in a radio link between the terminal device 10 and the reference device 100 comprises means for detecting radio link 102 failure or means for predicting radio link 102 failure based on radio link quality measurements over time.

[0136] Any suitable measurement may be used to evaluate the radio link quality of the radio link 102. For example, received signal strength may be used. For example, signal-to-noise ratio may be used. For example, in the 3rd Generation Partnership Project (3GPP), one or more of received signal strength indicator (RSSI), reference signal received power (RSRP), and reference signal received quality (RSRQ) may be used.

[0137] The evaluation of the radio link quality of the radio link 102 may be limited to the frequency resources used by the radio link 102 .

[0138] For example, degradation of the radio link quality may be detected 40 by comparing a suitable parameter (depending on one or more of the above-mentioned measurements) to a suitable threshold. In some examples, the comparison may include an integration of the suitable parameter over a time window before making the comparison.

[0139] For example, machine learning may be used to detect 40 degradation of radio link quality. For example, a neural network may be trained to recognize parameter patterns (eg, depending on the above measurements) that indicate degradation of quality, eg, indicating an impending future failure of the radio link 102.

[0140] In some but not necessarily all examples, the means 40 for detecting degradation of radio link quality in a radio link 102 between the terminal device 10 and the reference device 100 comprises means for detecting radio link 102 failure or means for predicting radio link 102 failure based on radio link quality measurements over time.

[0141] In some, but not necessarily all, examples, the apparatus 10 comprises means for determining positioning assistance information 20 based at least on a detected degradation of a radio link quality of a radio link 102 between the terminal apparatus 10 and a reference apparatus 100 .

[0142] For example, the content of the positioning assistance information 20 may vary as the radio link quality of the radio link 102 between the terminal device 10 and the reference device 100 is detected to be degraded.

[0143] The positioning assistance information 20 enables the other terminal device 200 to take preemptive action when a failure is predicted in a radio link that the other terminal device 200 is using or can use.

[0144] The content of the positioning assistance information 20 may be controlled to provide the other terminal device 200 with information that will assist the other terminal device 200 in predicting a failure of a radio link that the other terminal device 200 is using or may use.

[0145] The positioning assistance information 20 sent by the terminal device 100 to another terminal device 200 may, for example, identify one or more of the following:

[0146] an identifier of the reference device 100;

[0147] the position of the reference device 100;

[0148] the location of the terminal device 10;

[0149] The movement mode of the terminal device 10;

[0150] The location service level of the location session 110;

[0151] The time-frequency resources of the radio positioning reference signal transmitted via the radio link 102;

[0152] a cause of degradation of the radio link quality of the radio link 102 between the terminal device 10 and the reference device 100;

[0153] the duration of the degradation of the radio link quality of the radio link 102 between the terminal device 10 and the reference device 100; or

[0154] The information associated with the candidate reference device 100 is used to locate another terminal device 200 in the second positioning session 110 .

[0155] The reasons for the degradation of the radio link quality of the radio link 102 between the terminal device 10 and the reference device 100 may be, for example, due to changing characteristics of the terminal device 10 (e.g., speed), changing characteristics of the reference device 100 (e.g., speed), changing characteristics of the spatial relationship between the terminal device 10 and the reference device 100 (e.g., distance, multipath, physical obstacles), characteristics of the radio environment (e.g., interference).

[0156] The positioning service level of the positioning session 110 may specify, for example, a required accuracy and / or a required delay. A degradation of the radio link quality of the radio link 102 between the terminal device 10 and the reference device 100 may be defined relative to a current positioning service level of the positioning session 110 .

[0157] The transmission 12 of the positioning assistance information 20 to at least another terminal device 200 via the sidelink communication 30 may be as a unicast, multicast or broadcast message.

[0158] The transmission 12 of the positioning assistance information 20 via the sidelink communication 30 may be transmitted, for example, to a plurality of other terminal devices 200 .

[0159] Above for Figure 1 The description provided of a positioning session with a reference device 100 using a radio link 102 is also related to Figure 3 The use of the radio link 202 shown in FIG. 1 is related to a positioning session 210 of at least one reference device 100_2 .

[0160] Figure 3 The operation of the terminal device 10 is the same as that of the previous reference Figure 2 The description is the same except that the reference device 100 is referred to as a first reference device 100_1 .

[0161] The terminal device 10 is a target to be positioned, and the reference device 100_1 is an anchor point supporting positioning of the terminal device 10 in the first positioning session 110 in the first sidelink network.

[0162] The other terminal device 200 is a target to be positioned, and the reference device 100_2 is an anchor point supporting positioning of the other terminal device 200 in a second positioning session 210 between the other terminal device 200 and the reference device 100 in the second sidelink network.

[0163] The positioning of the terminal device 10 may be independent of the positioning of the terminal device 200. For example, the terminal device 10 positions itself using the reference device 100_1 instead of the other terminal device 200 as a reference, and the other terminal device 200 positions itself using the reference device 100_2 instead of the terminal device 10 as a reference.

[0164] exist Figure 3 In the embodiment, the terminal device 200 includes components for the following operations:

[0165] positioning 212 the terminal device 200 using the radio link 202 with at least the first reference device 100_2 in a second positioning session 210 ;

[0166] receiving positioning assistance information 20 from another terminal device 10 via sidelink communication 30, wherein the positioning assistance information 20 at least indicates degradation of a radio link quality of a radio link 102 between the other terminal device 10 and a second reference device 100_2; and

[0167] According to the received positioning assistance information 20 , in case that the quality of the radio link 202 between the terminal device 200 and the first reference device 100_2 is predicted to be degraded, it is determined 220 to perform a preemption action 230 .

[0168] In at least some examples, the radio link 202 includes receiving a radio positioning reference signal sent from the first reference device 100_2 to the terminal device 200 and / or includes sending a radio positioning reference signal from the terminal device 200 to the first reference device 100_2.

[0169] As described above, in at least some examples, the radio positioning reference signal is a sidelink positioning reference signal, and the first reference device 100_2 is a user equipment. The terminal device 200 is a target to be positioned, and the first reference device 100_2 is an anchor point for positioning the terminal device 200 in a second positioning session 210 in a second sidelink network, wherein the other terminal device 10 is a target to be positioned, and the second reference device 100_1 is an anchor point for positioning the other terminal device 10 in a first positioning session 210 between the other terminal device 10 in the first sidelink network and the second reference device 100_1.

[0170] As previously described, in other examples, the reference device 100 is a network node, and the radio positioning reference signal is a downlink positioning reference signal sent from the reference device 100 to the terminal device 10 and / or the radio positioning reference signal is an uplink positioning reference signal sent from the terminal device 10 to the reference device 100.

[0171] In some but not necessarily all examples, determining 220 to perform a preemption action 230 in the event that the quality of the radio link 202 is predicted to degrade based on the received positioning assistance information 20 includes determining 220 whether to perform a preemption action 230 .

[0172] In some but not necessarily all examples, determining 220 to perform preemptive action 230 in the event that quality of radio link 202 is predicted to degrade based on received positioning assistance information 20 includes determining 220 what action to preemptively occur.

[0173] It should be noted that the terminal 10 detects 40 a degradation in the radio link quality of the radio link 102 between the terminal device 10 and the reference device 100. This detection triggers an action at the terminal device 200 via the positioning assistance information 20. The terminal 200 does not detect a degradation in the radio link quality of the radio link 202 between the terminal device 200 and the reference device 100_2. Instead, it relies on the reception of the positioning assistance information 20 to provide information that can be used to predict (forecast) the degradation in the quality of the radio link 202 between the terminal device 200 and the first reference device 100_2. The action taken is preemptive in that it occurs before the degradation in the quality of the radio link 202 between the terminal device 200 and the first reference device 100_2 is detected by measurement.

[0174] In some but not necessarily all examples, the apparatus 200 includes a component 230 for performing a preemptive action.

[0175] In at least some examples, the component for performing the preemption action 230 includes a component for modifying the second positioning session 210 and / or a component for terminating the second positioning session 210 .

[0176] The second positioning session 210 may, for example, be modified to use different time-frequency resources for the radio link 202 between the terminal device 200 and the first reference device 100_2 .

[0177] For example, the second positioning session 210 may be terminated and a new positioning session may be started using a new radio link between the terminal device 200 and a new reference device 100_n.

[0178] In at least some examples, means for performing preemption actions 230 include means for configuring or reconfiguring a radio link for positioning.

[0179] For example, the radio link 202 may be reconfigured and use different time-frequency resources.

[0180] The radio link may be configured, for example, as a new reference device 100_n.

[0181] exist Figure 3 In the embodiment, the first reference device 100_2 and the second reference device 100_1 may be different devices or the same device.

[0182] Figure 3 An example is shown in which the first reference device 100_2 and the second reference device 100_1 are different devices. Figure 4 An example is shown in which the first reference device 100_2 and the second reference device 100_1 are the same device. Figure 3 The description also applies to Figure 4 .

[0183] exist Figure 4 In the embodiment, the terminal device 200 includes components for the following operations:

[0184] positioning 212 the terminal device 200 using the radio link 202 with at least the first reference device 100 in a second positioning session 210 ;

[0185] receiving positioning assistance information 20 from another terminal device 10 via sidelink communication 30, wherein the positioning assistance information 20 at least indicates a degradation of a radio link quality of a radio link 102 between the other terminal device 10 and a reference device 100; and

[0186] Based on the received positioning assistance information 20 , in case the quality of the radio link 202 between the terminal device 200 and the reference device 100 is predicted to degrade, it is determined 220 to perform a preemption action 230 .

[0187] In many cases, both targets 10, 200 are in a positioning session 110, 210 with the same anchor point 100. However, this is not always the case. Considering the case where there is congestion or high interference in the resource pool, the target 200 may benefit from receiving positioning assistance information 20 even if the anchor points 100_1, 100_2 are different, because congestion and high interference in the resource pool may affect all radio links (from different anchor points 100_n) in the corresponding resource pool.

[0188] Figure 5 Examples of modifications that may be made to any of the foregoing examples are shown. For ease of explanation, these modifications are interpreted as modifications to Figure 2 A supplement to the process shown in .

[0189] The device 10 includes means for transmitting the interruption notification capability 50 to the other terminal device 200 via the sidelink communication 30 before transmitting the positioning assistance information 20 to the other terminal device 200 via the sidelink communication 30 .

[0190] The interrupt notification capability 50 indicates to another terminal device 200 the capability of the terminal device 10 to provide the positioning assistance information 20 .

[0191] The interruption notification capability 50 sent by the terminal device 100 to another terminal device 200 may, for example, identify one or more of the following:

[0192] An identifier of the reference device 100 (or other reference device used for positioning);

[0193] the location of the terminal device 10;

[0194] The movement mode of the terminal device 10;

[0195] The location service level of the location session 110;

[0196] The time-frequency resources of the radio positioning reference signal transmitted via the radio link 102;

[0197] The information associated with the candidate reference device 100 is used to locate another terminal device 200 in the second positioning session 110 .

[0198] The interruption notification capability 50 sent by the terminal device 100 to another terminal device 200 may, for example, identify one or more of the following:

[0199] the characteristics of the terminal device 10 (e.g., speed),

[0200] Referring to a characteristic of the device 100 (e.g., speed),

[0201] the characteristics of the spatial relationship between the terminal device 10 and the reference device 100,

[0202] Characteristics of the radio environment (e.g. interference).

[0203] In some but not necessarily all examples, the interruption notification capability 50 is processed by the terminal apparatus 200. The terminal apparatus 200 may be configured to send an interruption notification request 52 to the terminal apparatus 10 based on the interruption notification capability 50 received from the terminal apparatus 10.

[0204] The interruption notification capability 50 indicates to another terminal device 200 the capability of the terminal device 10 to provide positioning assistance information 20. If the positioning assistance information 20 provided by the terminal device 10 is likely to contribute to the determination 220 to perform a preemption action 230 in the case of predicting that the quality of the radio link 202 between the terminal device 200 and the first reference device 100_2 is degraded, the terminal device 200 sends an interruption notification request 52 to the terminal device 10. If the positioning assistance information 20 provided by the terminal device 10 is unlikely to contribute to the determination 220 to perform a preemption action 230 in the case of predicting that the quality of the radio link 202 between the terminal device 200 and the first reference device 100_2 is degraded, the terminal device 200 does not send the interruption notification request 52 to the terminal device 10.

[0205] For example, if the location of the terminal device 200 is similar to that of the terminal device 10, the terminal device 200 sends the interruption notification request 52 to the terminal device 10. For example, if the location of the terminal device 200 is not similar to that of the terminal device 10, the terminal device 200 does not send the interruption notification request 52 to the terminal device 10.

[0206] For example, if the mobile mode of the terminal device 200 is similar to the mobile mode of the terminal device 10, the terminal device 200 sends the interruption notification request 52 to the terminal device 10. For example, if the mobile mode of the terminal device 200 is not similar to the mobile mode of the terminal device 10, the terminal device 200 does not send the interruption notification request 52 to the terminal device 10.

[0207] In some examples, the terminal device 10 sends the positioning assistance information 20 only after receiving the interruption notification request 52 , or the terminal device 10 sends the positioning assistance information 20 using unicast only after receiving the interruption notification request 52 .

[0208] In some examples, the terminal device 10 sends the positioning assistance information 20 without receiving the interruption notification request 52 , or the terminal device 10 sends the positioning assistance information 20 using broadcast or multicast without receiving the interruption notification request 52 .

[0209] The terminal device 200 includes means for sending an interrupt notification request 52 to the terminal device 10 via the side link communication 30 , requesting the terminal device 10 to provide the positioning assistance information 20 .

[0210] The interruption notification request 52 sent by the terminal device 200 to the terminal device 10 may, for example, identify one or more of the following:

[0211] an identifier of the reference device 100 used for locating the terminal device 200 in the second positioning session 210;

[0212] The movement pattern of the terminal device 200; or

[0213] Conditions for sending positioning assistance information 20.

[0214] In at least some examples, the device 10 includes a component for receiving an interruption notification request 52 from a terminal device 200 via the sidelink communication 30 before sending the positioning assistance information 20 to another terminal device 200 via the sidelink communication 30, wherein the positioning assistance information 20 is determined at least based on the interruption notification request 52.

[0215] The terminal device 200 may include means for receiving an interruption notification capability 50 from the terminal device 10 via the sidelink communication 30 before sending an interruption notification request 52 to another terminal device 10 via the sidelink communication 30. The interruption notification capability 50 indicates a capability of the terminal device 10 to provide positioning assistance information 20.

[0216] From the above, we can understand that Figures 1 to 5 An example of a method performed at the terminal device 10 is shown, comprising:

[0217] positioning 112 the terminal device 10 using a radio link 102 with at least a reference device 100 in a first positioning session 110 ;

[0218] detecting 40 a degradation of a radio link quality of a radio link 102 between the terminal device 10 and the reference device 100;

[0219] sending 12 positioning assistance information 20 to at least another terminal device 200 via a sidelink communication 30 in response to a detected degradation of a radio link quality of a radio link 102 between the terminal device 10 and a reference device 100,

[0220] The positioning assistance information 20 at least indicates degradation of the radio link quality of the radio link between the terminal device 10 and the reference device 100 .

[0221] From the above, we can understand that Figures 1 to 5 An example of a method performed at the terminal device 10 is shown, comprising:

[0222] positioning 212 the terminal device 200 using the radio link 202 with at least the first reference device 100_2 in a second positioning session 210 ;

[0223] receiving positioning assistance information 20 from another terminal device 10 via sidelink communication 30, wherein the positioning assistance information 20 at least indicates degradation of a radio link quality of a radio link 102 between the other terminal device 10 and a second reference device 100_1; and

[0224] According to the received positioning assistance information 20 , in case that the quality of the radio link 202 between the terminal device 200 and the first reference device 100_2 is predicted to be degraded, it is determined 220 to perform a preemption action 230 .

[0225] Figure 6 and Figure 7 Various examples are related to the previously described systems.

[0226] The performance requirements for different positioning service levels include one or more key performance indicators (KPIs) such as:

[0227] Horizontal and vertical accuracy, where vertical accuracy refers to altitude accuracy, determines floors in indoor use cases, and distinguishes between superimposed tracks for road and rail use cases (e.g., bridges).

[0228] Location service availability: The percentage of time the location service provides the required location-related data within the performance requirements, divided by the amount of time the system is expected to provide location services according to specifications in the target service area.

[0229] Location Services Latency: The time that elapses between an event that triggers the determination of location-related data and the time that location-related data becomes available at the system interface

[0230] Time to First Fix (TTFF): The time between the first triggering event to determine position-related data and the availability of position-related data at the positioning system interface.

[0231] Update rate

[0232] Energy consumption, etc.

[0233] Applications for positioning include vehicle-to-everything (V2X), public safety, commercial and industrial IoT (IIoT).

[0234] Example applications include:

[0235] Use cases that require lane-level positioning include vehicle platooning, collaborative lane merging, lane change warnings, emergency brake warnings, and intersection movement assistance. Use cases that require positioning below one meter include high-definition sensor sharing, vulnerable road users (VUR)-collision risk warnings, collaborative operations in emergency situations, real-time situational awareness, and high-definition maps.

[0236] Future factory scenarios such as augmented reality in smart factories, mobile control panels with safety features in smart factories (within factory hazardous areas), inbound logistics in manufacturing (driving trajectories for indoor autonomous driving systems (if supported by other sensors such as cameras, GNSS, IMU, etc.)

[0237] In the following:

[0238] Sidelink (SL) refers to user equipment (UE) to UE communication as described above, and the target UE refers to the UE to be located.

[0239] Anchor UE refers to a UE that supports positioning of the target UE, for example, by sending and / or receiving reference signals for positioning via the SL interface.

[0240] Sidelink Positioning Reference Signal (SL PRS) refers to a reference signal sent through the SL for positioning purposes.

[0241] SL PRS (pre) configuration is a term that collectively refers to the (pre) configuration parameters of SL PRS, such as time-frequency resources (including their bandwidth and periodicity); directionality-related parameters, for example, beam direction, beam width, number of beams; and transmit power, etc.

[0242] SL positioning is based on SL-PRS sent by multiple anchor UEs and received by the target UE (or SL-PRS exchange between anchor UE and target UE) to locate the target UE within the precise delay and accuracy requirements of the corresponding SL positioning session.

[0243] Figure 6 A SL positioning scenario is shown, where a target UE 200 is performing a SL positioning session, ie exchanging SL-PRS with two anchor UEs 100_1, 100_2 in order to determine its position. Here, the anchors 100_1, 100_2 are considered to provide SL-PRS assistance (including SL-PRS) to the target UE 200.

[0244] For the target UE, (re)establishing (or (re)configuring) a SL location session is expensive in terms of latency since it involves anchor point selection and SL-PRS configuration.

[0245] The selected anchor points may satisfy a set of conditions related to resource availability (available energy + time / frequency resources) and relative position of the anchor points to ensure the required positioning accuracy at the target UE. The latter aspect is related to the fact that if the selected anchor points are co-linear with the target UE, the target UE experiences a high geometric reduction in precision (GDOP) and the positioning accuracy is degraded. Therefore, the target UE may employ different techniques such as ranging between the target UE and the candidate anchor points or exchanging some auxiliary information (e.g. beam-specific measurements, gNB-specific measurements) between the target and candidate anchor points during the (re)selection of anchor points.

[0246] The target UE may need to exchange auxiliary information (eg, recommended SL-PRS resources) regarding SL-PRS configuration with the anchor point (ie, perform a series of handshakes) to avoid SL-PRS collisions at the target UE.

[0247] An additional series of handshakes occurs between the target and each anchor to determine which entities are involved, what type of signaling and reporting is required to complete the session, etc.

[0248] The SL positioning session may be interrupted / failed due to the target UE failing to receive SL-PRS from one or more anchor points, where the reasons for the reception failure are, for example, non-line-of-sight (NLOS) channel conditions between the target UE and the anchor points or high interference or resource conflicts at the target UE (such as, for example, SL-PRS conflicts).

[0249] In the following,

[0250] The first target UE-T1 is equivalent to Figure 4 The terminal device 200,

[0251] The second target UE-T2 is equivalent to Figure 4 The terminal device 10,

[0252] Anchor point UE-A1 is equivalent to Figure 4 The reference device 100,

[0253] The interruption notification 20 corresponds to the positioning assistance information 20 .

[0254] refer to Figure 7 , consider the SL-PRS reception at the mobile target UE-T2 at two different times. At time t1, UE-T2 successfully receives the SL-PRS sent by the anchor UE-A1. However, at time t2, the SL-PRS reception at UE-T2 fails due to factors such as buildings blocking the SL-PRS. Therefore, the SL positioning session between UE-T2 and the anchor UE-A1 is interrupted / failed.

[0255] When the session 110 is interrupted / failed due to any of the above events, the target UE needs to re-establish the SL positioning session, where the SL-PRS transmission 102 from the anchor UE-A1 is not successfully received by the target UE-T2.

[0256] However, re-establishing the SL positioning session with another suitable anchor point UE-A2 to replace the failed anchor point UE-A1 will incur a large delay at the target UE-T2, as it involves, for example, anchor point reselection, SL-PRS reconfiguration, etc. (as described above). Such a large delay may be unacceptable for many SL positioning use cases, especially for use cases corresponding to lower latency positioning service levels.

[0257] Early recognition of SL-PRS reception disruption at the target UE may enable the target UE to prepare and engage in SL positioning session disruption avoidance / minimization measures (eg, anchor UE reselection before the current anchor UE fails).

[0258] When an outage is encountered / predicted when receiving the SL-PRS sent by the first anchor UE 100 at the second target UE 10, the second target UE 10 sends an outage notification 20 to the first target UE 200, informing it of the (expected) inability to successfully receive the SL-PRS 202 from the first anchor UE 100. The first target UE 200 uses this notification 20 to determine whether its own SL positioning requires outage avoidance / minimization measures.

[0259] In at least some examples, the second target UE 10 is configured to:

[0260] Performing a SL positioning session with the anchor UE 100;

[0261] Determine that SL positioning with the anchor UE 100 is interrupted;

[0262] Determining whether to send an interruption notification 20 to a peer UE (first target UE 200);

[0263] An interruption notification 20 is sent to the target UE 200, informing it that it cannot continue the SL positioning session 110 with the anchor point 100 on some / all code-time-frequency resources.

[0264] The interrupt notification message 20 may include:

[0265] The reason for the outage, e.g., congestion, unavailable resources, or inability to use certain SL-PRS modes;

[0266] ID of the interrupted anchor UE;

[0267] The mobility pattern of the second target UE (e.g., speed, trajectory, route information)

[0268] the duration of the interruption (permanent or temporary);

[0269] Some / all time-frequency SPS / any resources where outages are expected;

[0270] Potential candidate anchor nodes for positioning and corresponding SL-PRS configurations are provided (introduced).

[0271] The first target UE 200 is configured as:

[0272] Performing a SL positioning session with the anchor UE 100;

[0273] Determine whether to perform SL location session termination / modification according to the interruption notification 20;

[0274] The SL positioning session termination, anchor point reselection or resource reselection with the anchor point is performed according to the determination.

[0275] In at least some further examples, the second target UE 10 is configured to:

[0276] Performing a SL positioning session with the anchor UE 100;

[0277] Determine that SL positioning with the anchor UE 100 is interrupted;

[0278] Receiving an interruption notification request 52 from another target UE (first target UE 200);

[0279] Sending interruption notification capability information 50 to other target UEs (first target UE 200), the information indicating its capability to send interruption notifications related to a group of anchor UEs 100;

[0280] determining whether to send an interruption notification 20 to a peer UE (a first target UE 200) based at least on the received interruption notification request 52;

[0281] An interruption notification 20 is sent to the target UE 200, informing it that it cannot continue the SL positioning session 102 with the anchor point 100 on some / all code-time-frequency resources.

[0282] The interrupt notification request message 20 may include:

[0283] A set of anchor UE IDs that another target UE (first target UE 200) is interested in;

[0284] The movement pattern of another target UE 200 (e.g., speed, trajectory, route information);

[0285] The trigger condition 20 is used to send the interrupt notification.

[0286] The interrupt notification capability message 50 may contain:

[0287] A set of anchor UE IDs that can provide interruption notifications 20;

[0288] The movement pattern of the second target UE 10 (eg, speed, trajectory, route information).

[0289] The first target UE 200 is configured as:

[0290] Performing a SL positioning session 210 with the anchor UE 100;

[0291] receiving interruption notification capability information 50 from the second target UE 10;

[0292] Sending an interruption notification request 52 to the second target UE 10;

[0293] Determining whether to perform SL location session termination / modification according to the received interruption notification 20;

[0294] The SL positioning session termination, anchor point reselection or resource reselection with the anchor point 100 is performed according to the determination.

[0295] Figure 7 The solution shown in is based on the fact that target UEs in an area experience similar conditions when performing SL communication with a common anchor UE 100, so that if another target UE 10 (referred to as the second target UE) experiences a disruption in communication with the anchor UE 100, it is beneficial to elevate this awareness to a target UE 200 (referred to as the first UE) in the same area.

[0296] This will allow the first UE 200 to prepare accordingly for such an outage, ie take eg outage avoidance / minimization measures for its own SL positioning.

[0297] In this regard, when the second target UE (UE-T2) 10 encounters / predicts an interruption in reception of the SL-PRS transmitted by the anchor UE (UE-A1) 100 , the second target UE (UE-T2) 10 transmits an interruption notification 20 to the first target UE (UE-T1) 200 .

[0298] For example, consider that UE-T1 (first target UE) and UE-T2 (second target UE) located in two different vehicles traveling on a highway lane are to perform a SL positioning session with the static anchor point UE-A1.

[0299] At time t2, UE-T2 is unable to receive SL-PRS due to building obstruction. UE-T2 then sends an interruption notification to UE-T1 to raise awareness of the interruption of receiving SL-PRS sent by the anchor UE 100 in the area. This allows UE-T1 to be aware of the potential upcoming SL-PRS reception interruption and take interruption avoidance measures by establishing a SL positioning session 310 with the alternative anchor UE-A2 100_n.

[0300] Therefore, when UE-T1 is in an area where UE-T2 has sent an interruption notification 20, UE-T1 can continue to position itself via the positioning session 310 without hindrance because it can receive SL-PRS assistance from the anchor point UE-A2 (rather than UE-A1) without interruption.

[0301] refer to Figure 7 , in stage 500 of method 600, a first target UE-T1 and a second target UE-T2 are conducting SL positioning sessions 210, 110 with a first anchor point UE-A1, respectively. UE-T1 and UE-T2 are receiving SL-PRS assistance. For example, SL-PRS is received from UE-A1 to locate itself. Here, UE-T1 (first target UE) and UE-T2 (second target UE) are considered to be in two different vehicles traveling on a highway lane and are performing SL positioning sessions with a static anchor point UE-A1.

[0302] In stage 501 of method 600 , UE- T2 optionally sends (eg, broadcasts) interruption notification capability information 50 to other target UEs (including UE- T1 ) to indicate its capability of sending interruption notifications 20 .

[0303] The interrupt notification capability message 50 may contain:

[0304] A set of anchor UE IDs that can determine SL-PRS reception interruption and provide interruption notification; and / or

[0305] The mobility pattern of UE-T2 (e.g., trajectory, speed, route information), etc.

[0306] UE-T2 identifies itself as an interruption notification node (i.e., a UE notifying other target UEs of the interruption) by:

[0307] (i) Unicast, i.e., through multiple SL connections with other target UEs.

[0308] (ii) By broadcasting a new interrupt notification capability message 50.

[0309] In stage 502 of method 600 , UE- T1 sends an interruption notification request 52 to UE- T2 .

[0310] The interrupt notification request 52 may consist of at least one or more of the following:

[0311] The set of anchor UE IDs that UE-T1 is interested in;

[0312] The mobility pattern of UE-T1 (e.g., velocity vector, trajectory, route information);

[0313] Trigger conditions for interruption notification (e.g., relative to a minimum RSRP of an anchor UE, notification 20 is triggered below the minimum RSRP, or interruption occurs if the number of anchor UEs exceeds a certain threshold number);

[0314] The duration and period that UE-T1 is interested in receiving outage notifications.

[0315] In some examples, upon receiving the interruption notification capability information 50 from UE- T2 , UE- T1 may request 52 UE- T2 to provide the interruption notification 20 .

[0316] In other examples, UE-T1 may request notifications from UE-T2 (eg, in unicast fashion) only if there is a high similarity between their mobility patterns and / or UE-T2 is capable of providing outage notifications on those anchor points of interest to UE-T1.

[0317] In these or other examples, UE-T1 can autonomously determine to send (eg, broadcast) an outage notification request without receiving outage notification capability information from neighboring UEs.

[0318] In stage 503 of method 600 , as part of an ongoing SL positioning session (see step 0 ), UE-A1 sends SL-PRS 102 to at least UE-T2 .

[0319] In phase 504 of the method 600 , a degradation of the radio link quality of the radio link 102 between UE- T2 and the anchor point UE- A1 is detected 40 .

[0320] For example, UE-T2 fails to successfully receive the SL-PRS transmitted by UE-A1, and thus determines 40 that UE-A1 is out of service. In this example, NLOS SL-PRS transmission due to building shading is considered to be the reason for the failure to successfully receive the SL-PRS at UE-T2.

[0321] In some examples, the outage of the anchor point UE-A1 is determined 40 only when the outage actually occurs.

[0322] In some examples, the outage with the anchor point UE-A1 is determined 40 based on a predicted / expected outage with the anchor point UE-A1.

[0323] In some examples, the prediction of the outages of the expected UE-T2 trajectory may be based on a history of Reference Signal Received Power (RSRP) measurements. Furthermore, UE-T2 may consider the expected outage rate (number of expected outages per unit time) as a criterion in the determination 40 .

[0324] In stage 505 of method 600 , when it is determined that the SL-PRS reception is interrupted, UE- T2 determines 42 whether to send an interruption notification 20 to UE- T1 based at least on the received interruption notification request 52 .

[0325] In some examples, UE-T2 may determine 42 to send an outage notification 20 to UE-T1 (e.g., in a unicast manner) only if there is a high similarity between the mobility patterns of UE-T1 and UE-T2 and / or UE-T2 has determined those anchor UE outages that are of interest to UE-T1.

[0326] In some examples, UE-T2 may autonomously determine 42 (e.g., in a broadcast manner) to send an outage notification 20 without any explicit request from UE-T1. For example, UE-T2 may send a notification 20 each time it encounters an outage in SL-PRS reception. In addition, in the notification 20, UE-T2 may include the IDs of all anchor points for which it encounters an outage.

[0327] In some examples, UE-T2 may first determine the level of degradation of positioning accuracy / reliability due to the interruption. If the accuracy / reliability level drops below a (pre)configured level, UE-T2 determines 42 to send an interruption notification 20. In another embodiment, UE-T2 determines 42 to send an interruption notification 20 if the duration of the degradation (i.e., the duration for which the accuracy / reliability remains outside the tolerable level) is higher than a certain (pre)configured duration.

[0328] In some examples, UE-T2 may determine 42 to send the notification 20 if the burst level of the outage is above a (pre-)configured threshold.

[0329] In some examples, the configuration on the burst level is configured by the network (LMF). Thus, the LMF sets the rules on how deep and how long a signal drop should trigger 42 an outage notification 20.

[0330] In some examples, the configuration on the burst level is configured by the peer UE (ie, UE-T2 is configured by UE-T1 as to how long an outage should last before triggering 42 an outage notification 20).

[0331] In stage 506 of the method 600 , UE- T2 sends an interruption notification 20 to the target UE- T1 , informing it that it cannot continue the SL positioning session 102 with the anchor UE- A1 on some / all code-time-frequency resources.

[0332] The interrupt notification message 20 may include:

[0333] The reason for the outage, such as congestion, unavailable resources or inability to use certain SL-PRS patterns. UE-T1 can use this information to avoid using such resources;

[0334] The ID of the interrupted anchor node;

[0335] a mobility pattern (e.g., velocity vector) of the second target UE-T2;

[0336] the duration of the interruption (permanent or temporary);

[0337] Some / all time-frequency SPS / any resources where outages are expected;

[0338] Providing (introducing) potential candidate anchor nodes for positioning and corresponding configurations, as well as additional relevant information for improving positioning;

[0339] The interruption rate probability of the corresponding trajectory / route relative to the anchor UE.

[0340] Phase 507 of the method 600 comprises determining 220 to perform a preemption action 230 in case a quality degradation of the radio link 202 between the terminal device 200 and the first reference device 100_2 is predicted according to the received interruption notification message 20 .

[0341] For example, after receiving the interruption notification 20, UE-T1 determines 220 whether to perform 230 SL location session termination / modification according to the interruption notification 20 from UE-T2.

[0342] In some examples, UE-T1 may determine 220 to perform 230 SL location session termination / modification only when SL-PRS reception in UE-T1's SL-PRS resources / configuration (used by UE-A1 to send SL-PRS to UE-T1) is expected to face interruption (as indicated in the interruption notification 20).

[0343] In some examples, UE-T1 may determine 220 to perform 230 SL location session termination / modification only if there is a high similarity between their movement patterns.

[0344] In some examples, UE-T1 may determine 220 to perform 230 SL location session termination / modification only if the interruption duration is above a certain (pre-)configured threshold.

[0345] In some examples, UE-T1 may select an additional anchor UE for its SL positioning and may determine not to terminate the SL location session with the anchor (UE-A1) indicated in the interruption notification 20 unless the SL-PRS reception at UE-T1 is interrupted. If an interruption with respect to UE-A1 occurs at UE-T1, UE-T1 will use the SL-PRS sent from the additional anchor UE-A2.

[0346] In stage 508 of method 600, after making a positive determination in step 7, UE-T1 performs 230 SL positioning session termination, anchor point reselection or SL-PRS resource reselection with anchor point UE-A1. In this way, UE-T1 avoids potential SL positioning session interruption and can therefore continue to position itself without any obstruction or delay.

[0347] In some examples, if an outage is expected in the current SL-PRS resources (used by UE-A1 to send SL-PRS to UE-T1), UE-T1 triggers SL-PRS resource reselection by providing inter-UE coordination (IUC) information with non-preferred resources (resources determined to be outage by UE-T2) to UE-A1.

[0348] In some examples, during anchor UE reselection, UE-T1 may consider alternative anchor UEs proposed by UE-T2 for the SL positioning session.

[0349] In stage 509 of method 600, target UE-T1 establishes a SL positioning session 310 with anchor point UE-A2. In this example, it is assumed that UE-T1 establishes and performs a SL positioning session 310 with another anchor point UE-A2 when UE-T2 receives an interruption notification 20 on UE-A1. In this way, UE-T1 avoids any SL positioning session interruption, which may otherwise occur due to a potential reception failure of the SL-PRS 202 sent by UE-A1.

[0350] The proposed solution enables the target UE to recognize the SL-PRS reception interruption early. This allows the UE to participate in SL positioning session interruption avoidance / minimization measures (e.g., anchor point reselection before the current anchor point fails) so that it can continue to locate itself without any obstruction / interruption or delay. This is especially beneficial for positioning use cases that require extremely high availability and low latency positioning services, such as V2X (autonomous driving) and IIoT (factory scenarios).

[0351] Figure 8An example of a controller 400 suitable for use with the apparatus 10, 200 is shown. The controller 400 may be implemented as a controller circuit system. The controller 400 may be implemented solely in hardware, may also have certain aspects in software (including separate firmware), or may be a combination of hardware and software (including firmware).

[0352] like Figure 8 As shown, the controller 400 may be implemented using instructions that implement hardware functionality, for example, by using executable instructions of a computer program 406 in a general or special purpose processor 402, which instructions may be stored on a computer readable storage medium (disk, memory, etc.) and executed by such a processor 402.

[0353] The processor 402 is configured to read from and write to the memory 404. The processor 402 may also include an output interface through which the processor 402 outputs data and / or commands and an input interface through which data and / or commands are input to the processor 402.

[0354] The memory 404 stores a computer program 406, which includes computer program instructions (computer program code) that control the operation of the device 10, 200 when the computer program instructions are loaded into the processor 402. The computer program instructions of the computer program 406 provide logic and routines that enable the device to perform the methods shown in the figures. The processor 402 can load and execute the computer program 406 by reading the memory 404.

[0355] The device 10 comprises:

[0356] at least one processor 402; and

[0357] At least one memory 404 including computer program code

[0358] The at least one memory 404 and the computer program code are configured to, together with the at least one processor 402, cause the apparatus 10, 200 to at least execute:

[0359] positioning 112 a terminal device 10 using a radio link 102 with at least one reference device 100 in a first positioning session 110 ;

[0360] detecting 40 a degradation of a radio link quality of a radio link 102 between the terminal device 10 and the reference device 100;

[0361] sending 12 positioning assistance information 20 to at least another terminal device 200 via a sidelink communication 30 in response to a detected degradation of a radio link quality of a radio link 102 between the terminal device 10 and a reference device 100,

[0362] The positioning assistance information 20 at least indicates degradation of the radio link quality of the radio link between the terminal device 10 and the reference device 100 .

[0363] The device 10 comprises:

[0364] at least one processor 402; and

[0365] at least one memory 404 including computer program code,

[0366] The at least one memory stores instructions that, when executed by the at least one processor 402, cause the apparatus to at least perform:

[0367] positioning 112 a terminal device 10 using a radio link 102 with at least one reference device 100 in a first positioning session 110 ;

[0368] detecting 40 a degradation of a radio link quality of a radio link 102 between the terminal device 10 and the reference device 100;

[0369] sending 12 positioning assistance information 20 to at least another terminal device 200 via a sidelink communication 30 in response to a detected degradation of a radio link quality of a radio link 102 between the terminal device 10 and a reference device 100,

[0370] The positioning assistance information 20 at least indicates degradation of the radio link quality of the radio link between the terminal device 10 and the reference device 100 .

[0371] The apparatus 200 comprises:

[0372] at least one processor 402; and

[0373] At least one memory 404 including computer program code

[0374] The at least one memory 404 and the computer program code are configured to, together with the at least one processor 402, cause the apparatus 10, 200 to at least execute:

[0375] positioning 212 the terminal device 200 using the radio link 202 with at least the first reference device 100_2 in a second positioning session 210 ;

[0376] receiving positioning assistance information 20 from another terminal device 10 via sidelink communication 30, wherein the positioning assistance information 20 at least indicates degradation of a radio link quality of a radio link 102 between the other terminal device 10 and a second reference device 100_1; and

[0377] According to the received positioning assistance information 20 , when it is predicted that the quality of the radio link 202 between the terminal device 200 and the first reference device 100_2 will be degraded, it is determined 220 to perform a preemption action 230 .

[0378] The apparatus 200 comprises:

[0379] at least one processor 402; and

[0380] at least one memory 404 including computer program code,

[0381] The at least one memory stores instructions that, when executed by the at least one processor 402, cause the apparatus to at least perform:

[0382] positioning 212 the terminal device 200 using the radio link 202 with at least the first reference device 100_2 in a second positioning session 210 ;

[0383] receiving positioning assistance information 20 from another terminal device 10 via sidelink communication 30, wherein the positioning assistance information 20 at least indicates degradation of a radio link quality of a radio link 102 between the other terminal device 10 and a second reference device 100_1; and

[0384] According to the received positioning assistance information 20 , when it is predicted that the quality of the radio link 202 between the terminal device 200 and the first reference device 100_2 will be degraded, it is determined 220 to perform a preemption action 230 .

[0385] like Fig. 9 As shown, the computer program 406 may arrive at the apparatus 10, 200 via any suitable transmission mechanism 408. The transmission mechanism 408 may be, for example, a machine-readable medium, a computer-readable medium, a non-transitory computer-readable storage medium, a computer program product, a storage device, a recording medium (such as a compact disk read-only memory (CD-ROM) or a digital versatile disk (DVD) or a solid-state memory), an article of manufacture including or tangibly embodying the computer program 406. The transmission mechanism may be a signal configured to reliably transmit the computer program 406. The apparatus 10, 200 may propagate or transmit the computer program 406 as a computer data signal.

[0386] The computer program instructions are used to cause the apparatus 10 to perform at least the following operations or to perform at least the following operations:

[0387] positioning 112 a terminal device 10 using a radio link 102 with at least one reference device 100 in a first positioning session 110 ;

[0388] detecting 40 a degradation of a radio link quality of a radio link 102 between the terminal device 10 and the reference device 100;

[0389] sending 12 positioning assistance information 20 to at least another terminal device 200 via a sidelink communication 30 in response to a detected degradation of a radio link quality of a radio link 102 between the terminal device 10 and a reference device 100,

[0390] The positioning assistance information 20 at least indicates degradation of the radio link quality of the radio link between the terminal device 10 and the reference device 100 .

[0391] The computer program instructions are used to cause the apparatus 200 to at least perform the following operations or to perform at least the following operations:

[0392] positioning 212 the terminal device 200 using the radio link 202 with at least the first reference device 100_2 in a second positioning session 210 ;

[0393] receiving positioning assistance information 20 from another terminal device 10 via sidelink communication 30, wherein the positioning assistance information 20 at least indicates degradation of a radio link quality of a radio link 102 between the other terminal device 10 and a second reference device 100_1; and

[0394] According to the received positioning assistance information 20 , when it is predicted that the quality of the radio link 202 between the terminal device 200 and the first reference device 100_2 will be degraded, it is determined 220 to perform a preemption action 230 .

[0395] The computer program instructions may be embodied in a computer program, a non-transitory computer readable medium, a computer program product, a machine readable medium. In some but not necessarily all examples, the computer program instructions may be distributed among multiple computer programs.

[0396] Although memory 404 is shown as a single component / circuitry, it may be implemented as one or more separate components / circuitry, some or all of which may be integrated / removable and / or may provide permanent / semi-permanent / dynamic / cache storage.

[0397] Although processor 402 is shown as a single component / circuitry, it may be implemented as one or more separate components / circuitry, some or all of which may be integrated / detachable. Processor 402 may be a single-core processor or a multi-core processor.

[0398] References to "computer-readable storage medium", "computer program product", "tangibly embodied computer program", etc. or "controller", "computer", "processor", etc. should be understood to include not only computers with different architectures (such as single / multi-processor architectures and sequential (von Neumann) / parallel architectures), but also special-purpose circuits (such as field programmable gate arrays (FPGAs), application-specific circuits (ASICs), signal processing devices and other processing circuit systems). References to computer programs, instructions, codes, etc. should be understood to include software or firmware for programmable processors, such as the programmable content of hardware devices (whether instructions for a processor, or configuration settings for a fixed-function device, gate array or programmable logic device, etc.).

[0399] As used in this application, the term "circuitry" may refer to one, more, or all of the following:

[0400] (a) pure hardware circuit implementation (e.g., implementation in analog and / or digital circuitry only) and

[0401] (b) a combination of hardware circuitry and software such as (where applicable):

[0402] (i) a combination of analog and / or digital hardware circuitry and software / firmware, and

[0403] (ii) any portion of hardware processors and software (including digital signal processors), software and memory that work together to enable a device such as a mobile phone or server to perform its functions, and

[0404] (c) A hardware circuit and / or processor, such as a microprocessor or portion of a microprocessor, requires software (such as firmware) to operate, but the software may not be present when it is not required to operate.

[0405] This definition of circuitry applies to all uses of this term in this application, including in any claims. As another example, as used in this application, the term "circuitry" also covers an implementation of merely a hardware circuit or processor and its accompanying software and / or firmware. The term "circuitry" also covers, for example, a baseband integrated circuit of a mobile device or a similar integrated circuit in a server, cellular network device, or other computing or network device, if applicable to a particular claim element.

[0406] The blocks shown in the drawings may represent steps in a method and / or code sections in a computer program 406. The description of a particular order of blocks does not necessarily mean that the blocks have a required or preferred order, and the order and arrangement of the blocks may vary. In addition, some blocks may be omitted.

[0407] If a structural feature has been described, it may be replaced by a means for performing one or more of the functions of the structural feature, whether that function is explicitly or implicitly described.

[0408] In some but not necessarily all examples, device 10, 200 is configured to transmit data from device 10, 200, wherein the data may or may not be stored locally in memory 404 of device 10, 200, and the data may or may not be processed locally by the circuit system or processor of device 10, 200.

[0409] For example, the data may be measurement data or data generated by processing measurement data.

[0410] The data may be stored remotely on one or more devices in a processed or unprocessed format. The data may be stored in the cloud.

[0411] The data may be processed remotely on one or more devices. The data may be processed partly locally and partly remotely on one or more devices.

[0412] Data may be transmitted wirelessly to a remote device via short-range radio communications (such as Wi-Fi or Bluetooth) or a long-range cellular radio link. The device may include a communication interface (such as, for example, a radio transceiver for data communications).

[0413] The device 10, 200 may be part of an Internet of Things, forming part of a larger distributed network.

[0414] The processing of data, whether local or remote, may be for health monitoring, data aggregation, patient monitoring, vital signs monitoring, or other purposes.

[0415] Whether local or remote, the processing of the data may involve artificial intelligence or machine learning algorithms. For example, the data may be used as learning input to train a machine learning network, or may be used as a query input to a machine learning network to provide a response. The machine learning network may use, for example, linear regression, logistic regression, vector support machine, or a non-recurrent machine learning network, such as a single or multi-layer hidden layer neural network.

[0416] Whether local or remote, the processing of data may generate an output. The output may be transmitted to the device 10, 200, and the device may generate an output perceivable by the subject, such as an audio output, a visual output, or a tactile output.

[0417] The system, apparatus, method and computer program can use machine learning, which can include statistical learning. Machine learning is a field of computer science that enables computers to learn without explicit programming. If the computer's performance on tasks in T (measured by P) improves with experience E, the computer learns certain task categories T and performance metrics P from experience E. Computers can usually learn from previous training data to make predictions about future data. Machine learning includes fully or partially supervised learning and fully or partially unsupervised learning. It can achieve discrete outputs (e.g., classification, clustering) and continuous outputs (e.g., regression). Machine learning can be implemented, for example, using different methods, such as cost function minimization, artificial neural networks, support vector machines, and Bayesian networks. Cost function minimization can be used, for example, for linear and polynomial regression and K-means clustering. Artificial neural networks (e.g., with one or more hidden layers) simulate complex relationships between input vectors and output vectors. Support vector machines can be used for supervised learning. A Bayesian network is a directed acyclic graph that represents the conditional independence of multiple random variables.

[0418] As used herein, a "module" refers to a unit or device that does not include certain parts / components added by the end manufacturer or user.

[0419] The above examples serve as supporting components for:

[0420] Automotive systems; telecommunications systems; electronic systems, including consumer electronics; distributed computing systems; media systems for generating or presenting media content, including audio, video and audiovisual content and mixed, mediated, virtual and / or augmented reality; personal systems, including personal health systems or personal fitness systems; navigation systems; user interfaces, also known as human-machine interfaces; networks, including cellular, non-cellular and fiber optic networks; ad hoc networks; the Internet; the Internet of Things; virtualized networks; and related software and services.

[0421] According to the examples of the present disclosure, the device can be set in an electronic device, such as a mobile terminal. However, it should be understood that the mobile terminal is only an example of an electronic device that will benefit from the implementation examples of the present disclosure, and therefore it should not be regarded as limiting the scope of the present disclosure to this. Although in some implementation examples, the device can be set in a mobile terminal, other types of electronic devices, such as but not limited to: mobile communication devices, handheld portable electronic devices, wearable computing devices, portable digital assistants (PDAs), pagers, mobile computers, desktop computers, televisions, gaming devices, laptops, cameras, video recorders, GPS devices, and other types of electronic systems, can easily adopt the examples of the present disclosure. In addition, whether the device is intended to provide mobility, the examples of the present disclosure can be easily adopted.

[0422] The term "include" is used in this document in an inclusive rather than exclusive sense. That is, any reference to X including Y indicates that X may include only one Y or may include more than one Y. If "include" is to be used in an exclusive sense, this may be made clear in the context by referring to "include only one..." or using "consisting of..."

[0423] In this specification, the words "connected", "coupled" and "in communication" and their derivatives mean operationally connected / coupled / in communication. It should be understood that any number or combination of intermediate components (including no intermediate components) may be present, i.e., to provide direct or indirect connection / coupling / in communication. Any such intermediate components may include hardware and / or software components.

[0424] As used herein, the term "determine / decide" (and its grammatical variations) may include (but are not limited to): calculate, compute, process, derive, measure, investigate, identify, look up (e.g., look up in a table, database or other data structure), determine, etc. In addition, "determine" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), obtaining, etc. In addition, "determine / decide" may include parsing, selecting, choosing, establishing, etc.

[0425] In this specification, reference has been made to various examples. The description of features or functions associated with an example indicates that these features or functions are present in the example. Whether explicitly stated or not, the use of the term "example" or "for example" or "may" or "might" in the text indicates that these features or functions are at least present in the example, whether or not described as an example, and they may, but not necessarily, be present in some or all other examples. Therefore, "example", "for example", "may" or "might" refers to a specific instance in an example class. The attributes of an instance may be attributes of only that instance, or attributes of the class, or attributes of a subclass of the class, which includes some but not all instances in the class. Therefore, features described with reference to one example rather than with reference to another example are implicitly disclosed, and may be used in the other example as part of a working combination where possible, but not necessarily in the other example.

[0426] Although the preceding paragraphs have described the examples with reference to various examples, it should be appreciated that modifications to the examples given can be made without departing from the scope of the claims.

[0427] Features described in the preceding description may be used in combinations other than those explicitly described above.

[0428] Although functions have been described with reference to certain features, those functions may be performable by other features whether described or not.

[0429] Although features have been described with reference to certain examples, those features may also be present in other examples whether described or not.

[0430] The terms "a", "an" or "the" used in this document have an inclusive and non-exclusive meaning. That is, any reference to X that includes a / an / the Y indicates that X may include only one Y or may include multiple Ys, unless the context clearly indicates the contrary. If the use of "a", "an" or "the" is intended to be exclusive, it will be clear from the context. In some cases, "at least one" or "one or more" may be used to emphasize the inclusive meaning, but the absence of these terms should not be construed as implying any exclusive meaning.

[0431] The presence of a feature (or combination of features) in a claim refers to the feature or (combination of features) itself, and also refers to features that achieve substantially the same technical effect (equivalent features). Equivalent features include, for example, features that are variants and achieve substantially the same result in substantially the same way. Equivalent features include, for example, features that perform substantially the same function in substantially the same way to achieve substantially the same result.

[0432] In this specification, reference has been made to various examples using adjectives or adjective phrases to describe example features. Such description of features in relation to the examples indicates that the features exist in some examples exactly as described, and in other examples substantially as described.

[0433] The above description describes some examples of the present disclosure, however, one of ordinary skill in the art will appreciate that there may be alternative structures and method features that provide equivalent functionality to the specific examples of the above structures and features, and have been omitted from the above description for the sake of brevity and clarity. Nevertheless, the above description should be understood to implicitly include references to such alternative structures and method features that provide equivalent functionality, unless such alternative structures or method features are explicitly excluded in the above description of examples of the present disclosure.

[0434] While an effort has been made in the foregoing description to draw attention to those features regarded as important, it should be understood that the applicant may seek protection by way of claims for any patentable feature or combination of features mentioned above and / or shown in the drawings, whether or not emphasis has been placed thereon.

Claims

1. A terminal device, comprising components for: positioning the terminal device using a radio link with at least one reference device in a first positioning session; detecting a degradation of a radio link quality of the radio link between the terminal device and the reference device; sending positioning assistance information to at least another terminal device via sidelink communication in response to the detected degradation of the radio link quality of the radio link between the terminal device and the reference device, The positioning assistance information at least indicates degradation of the radio link quality of the radio link between the terminal device and the reference device.

2. The terminal device according to claim 1, wherein the radio link comprises receiving a radio positioning reference signal sent from the reference device to the terminal device and / or comprises sending a radio positioning reference signal from the terminal device to the reference device. The terminal device according to claim 2 , wherein the radio positioning reference signal is a sidelink positioning reference signal.

4. The terminal device according to claim 3, wherein the terminal device is a target to be positioned, and the reference device is an anchor point in a first sidelink network that supports positioning the terminal device in the first positioning session, and wherein the other terminal device is a target to be positioned, and the reference device is an anchor point in a second sidelink network that supports positioning the other terminal device in a second positioning session between the other terminal device and the reference device.

5. A terminal device according to claim 2, wherein the reference device is a network node, and the radio positioning reference signal is a downlink positioning reference signal sent from the reference device to the terminal device and / or the radio positioning reference signal is an uplink positioning reference signal sent from the terminal device to the reference device.

6. A terminal device according to any preceding claim, wherein the means for detecting degradation of the quality of a radio link between the terminal device and the reference device comprises: Means for detecting radio link failure, or means for predicting radio link failure based on measurements of radio link quality over time.

7. A terminal device according to any one of the preceding claims, comprising: Means for determining said positioning assistance information based at least on said detected degradation of radio link quality of said radio link between said terminal device and said reference device.

8. The terminal device according to any one of claims 2 to 7, wherein the positioning assistance information identifies at least one of the following: an identifier of the reference device; the location of the reference device; the location of the terminal device; The movement mode of the terminal device; a positioning service level of the positioning session; time-frequency resources of a radio positioning reference signal transmitted over the radio link; a cause of degradation of the radio link quality of the radio link between the terminal device and the reference device; a duration of degradation of the radio link quality of the radio link between the terminal device and the reference device; or Information associated with an alternative reference device for locating the other terminal device in the second positioning session.

9. The terminal device according to any one of the preceding claims comprises a component for sending an interrupt notification capability to the other terminal device via side link communication before sending the positioning assistance information to the other terminal device via side link communication, wherein the interrupt notification capability indicates the ability of the terminal device to provide the positioning assistance information.

10. The terminal device according to any one of the preceding claims, comprises a component for receiving an interruption notification request from the other terminal device via side link communication before sending positioning assistance information to the other terminal device via side link communication, wherein the positioning assistance information is determined at least based on the interruption notification request.

11. The terminal device according to claim 10, wherein the interrupt notification request comprises at least one of the following: an identifier of a reference device for locating the other terminal device in the second positioning session; The movement mode of the other terminal device; or The conditions for sending the positioning assistance information.

12. A terminal device according to any one of the preceding claims, configured as a user equipment, the user equipment comprising a radio transceiver for communicating with a cell node of a radio access network, wherein the sidelink communication is performed between the user equipment and other user equipment without using the radio access network.

13. A computer program which, when executed on a computer of a terminal device, performs: positioning the terminal device using a radio link with at least one reference device in a first positioning session; detecting a degradation of a radio link quality of the radio link between the terminal device and the reference device; sending positioning assistance information to at least another terminal device via sidelink communication in response to the detected degradation of the radio link quality of the radio link between the terminal device and the reference device, The positioning assistance information at least indicates degradation of the radio link quality of the radio link between the terminal device and the reference device.

14. A method performed at a terminal device, comprising: using a radio link with at least one reference device in a first positioning session; detecting a degradation of a radio link quality of the radio link between the terminal device and the reference device; sending positioning assistance information to at least another terminal device via sidelink communication in response to the detected degradation of the radio link quality of the radio link between the terminal device and the reference device, The positioning assistance information at least indicates degradation of the radio link quality of the radio link between the terminal device and the reference device.

15. A terminal device, comprising components for: using in a second positioning session a radio link with at least a first reference device; receiving positioning assistance information from another terminal device via sidelink communication, wherein the positioning assistance information at least indicates degradation of a radio link quality of a radio link between the another terminal device and a second reference device; and According to the received positioning assistance information, when degradation of the radio link between the terminal device and the first reference device is predicted, it is determined to perform a preemption action.

16. The terminal device of claim 15, wherein the radio link comprises receiving a radio positioning reference signal sent from the first reference device to the terminal device and / or comprises sending a radio positioning reference signal from the terminal device to the first reference device. The terminal device according to claim 16 , wherein the radio positioning reference signal is a sidelink positioning reference signal.

18. A terminal device according to claim 15, 16 or 17, wherein the terminal device is a target to be positioned, and the first reference device is an anchor point in a second sidelink network that supports positioning the terminal device in the second positioning session, and wherein the other terminal device is a target to be positioned, and the second reference device is an anchor point in a first sidelink network that supports positioning the other terminal device in a first positioning session between the other terminal device and the second reference device.

19. The terminal device according to any one of claims 15 to 18, comprising means for performing a preemption action, the means comprising means for modifying the second positioning session and / or means for terminating the second positioning session.

20. The terminal device according to any one of claims 15 to 19, comprising a means for sending an interrupt notification request to the other terminal device via side link communication, the interrupt notification request requesting the other terminal device to provide the positioning assistance information.

21. The terminal device according to claim 20, wherein the interrupt notification request comprises at least one of the following: an identifier of the first reference device for locating the terminal device in the second positioning session; The movement pattern of the terminal device; or The conditions for sending the positioning assistance information.

22. The terminal device according to any one of claims 15 to 21, wherein the positioning assistance information identifies at least one of the following: an identifier of the second reference device; the position of the second reference device; the location of the other terminal device; a movement mode of the other terminal device; a positioning service level of the first positioning session for locating the other terminal device; time-frequency resources of a radio positioning reference signal transmitted in the first positioning session over the radio link between the other terminal device and the second reference device; a cause of degradation of the radio link quality of the radio link between the other terminal device and the second reference device; a duration of degradation of the radio link quality of the radio link between the other terminal device and the second reference device; or Information associated with an alternative reference device for locating the terminal device in the second positioning session.

23. The terminal device according to any one of claims 15 to 22 comprises a component for receiving an interruption notification capability from the other terminal device via side link communication before sending the interruption notification request to the other terminal device via side link communication, wherein the interruption notification capability indicates the ability of the other terminal device to provide the positioning assistance information. 24 . The terminal device according to claim 15 , wherein the first reference terminal device is the second reference terminal device.

25. A computer program which, when executed on a computer of a terminal device, performs: using in a second positioning session a radio link with at least a first reference device; causing, via the sidelink communication, receiving positioning assistance information from another terminal device, wherein the positioning assistance information at least indicates a degradation of a radio link quality of a radio link between the another terminal device and a second reference device; According to the received positioning assistance information, when degradation of the radio link between the terminal device and the first reference device is predicted, it is determined to perform a preemption action.

26. A method performed at a terminal device, comprising: using in a second positioning session a radio link with at least a first reference device; receiving positioning assistance information from another terminal device via sidelink communication, wherein the positioning assistance information at least indicates a degradation of a radio link quality of a radio link between the another terminal device and a second reference device; According to the received positioning assistance information, when degradation of the radio link between the terminal device and the first reference device is predicted, it is determined to perform a preemption action.

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