Patent Description:
The ability of devices in a wireless network to be aware of their positions continues to become an important feature. Some devices in the network may be aware of their positions already (such as, gNBs), while some device may be not (such as, a UE). Positioning schemes in the wireless network typically rely on timing-based techniques, angle-based techniques, or a hybrid technique. One timing-based technique is based on round trip time (RTT) estimates. If the RTTs between a UE and multiple gNBs are estimated, the position of the UE can be determined. In the latest 3GPP specifications (Release <NUM>), it has been agreed that multi-cell RTT based positioning is to be supported in new radio access (NR). Compared with other timing-based techniques, the RTT based positioning methods do not suffer from synchronization errors.

In the multi-cell RTT based positioning, the neighbor cell RTT needs to be estimated though a downlink (DL) and uplink (UL) signaling exchange procedure. Specifically, the neighbor cell needs to estimate receiving timing by measuring a UL reference signal (RS) from a terminal device (such as, a UE). However, the hearability of the UL signal may be a challenge for a remote neighbor cell due to low transmit power. Furthermore, in some scenarios, there may be a large difference between DL and UL link budgets. The link budget difference further decreases the hearability for the UL signaling compared with the DL signaling. In addition to the link budget difference, the terminal device may also beam form its transmission. Without proper beam management between the terminal device and the neighbor cell, the hearablity of the UL signaling may be further decreased.

The document <NPL>), discloses a discussion on a combination of DL & UL based positioning.

In general, example embodiments of the present disclosure provide methods, devices, apparatuses and computer readable storage media for multi-cell positioning.

Through the more detailed description of some embodiments of the present disclosure in the accompanying drawings, the above and other objects, features and advantages of the present disclosure will become more apparent, wherein:.

As used herein, the term "wireless communication network" refers to a network following any suitable wireless communication standards, such as New Radio (NR), Long Term Evolution (LTE), LTE-Advanced (LTE-A), Wideband Code Division Multiple Access (WCDMA), High-Speed Packet Access (HSPA), and so on. The "wireless communication network" may also be referred to as a "wireless communication system. " Furthermore, communications between network devices, between a network device and a terminal device, or between terminal devices in the wireless communication network may be performed according to any suitable communication protocol, including, but not limited to, Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Long Term Evolution (LTE), New Radio (NR), wireless local area network (WLAN) standards, such as the IEEE <NUM> standards, and/or any other appropriate wireless communication standard either currently known or to be developed in the future.

As used herein, the term "network device" refers to any suitable device at a network side of a communication network. The network device may include any suitable device in an access network of the communication network, for example, including a node B (NodeB or NB), an evolved NodeB (eNodeB or eNB), a New Radio (NR) NB (also referred to as a gNB), a Remote Radio Unit (RRU), a radio header (RH), a remote radio head (RRH), a relay, a low power node such as a femto, a pico, and so forth, depending on the applied terminology and technology.

The terminal device may include, but not limited to, a mobile phone, a cellular phone, a smart phone, voice over IP (VoIP) phones, wireless local loop phones, a tablet, a wearable terminal device, a personal digital assistant (PDA), portable computers, desktop computer, image capture terminal devices such as digital cameras, gaming terminal devices, music storage and playback appliances, vehicle-mounted wireless terminal devices, wireless endpoints, mobile stations, laptop-embedded equipment (LEE), laptop-mounted equipment (LME), USB dongles, smart devices, wireless customer-premises equipment (CPE) and the like.

As yet another example, in an Internet of Things (IOT) scenario, a terminal device may represent a machine or other device that performs monitoring and/or measurement, and transmits the results of such monitoring and/or measurements to another terminal device and/or network device. The terminal device may in this case be a machine-to-machine (M2M) device, which may in a 3GPP context be referred to as a machine-type communication (MTC) device. As one particular example, the terminal device may be a UE implementing the 3GPP Narrow Band Internet of Things (NB-IoT) standard. Examples of such machines or devices are sensors, metering devices such as power meters, industrial machinery, or home or personal appliances, for example refrigerators, televisions, personal wearables such as watches etc. In other scenarios, a terminal device may represent a vehicle or other equipment that is capable of monitoring and/or reporting on its operational status or other functions associated with its operation.

In timing-based positioning solutions, one factor that plays an important role in the performance is the number of hearable network devices in an area of interest, such as an environment where there are some target terminal devices to be positioned. As used herein, the word "hearable" means that the signal quality is sufficiently strong, such that the receiving device can make reasonable timing estimates based on the reception. In principle, the positioning error decrease with the number of hearable network devices being increased.

As described above, in the multi-cell RTT based positioning methods, the neighbor cell RTT needs to be estimated though a DL and UL signaling exchange procedure. More specifically, the neighbor cell needs to estimate receiving timing by measuring a UL RS from a UE. However, the hearability of the UL signal may be a challenge for a remote neighbor cell due to low transmit power. Furthermore, in some scenarios, there may be a large difference between DL and UL link budgets. The link budget difference further decreases the hearability for the UL signaling compared with the DL signaling. In addition to the link budget difference, the UE may also beam form its transmission. Without proper beam management between the UE and the neighbor cell, the hearability of the UL signaling may be further decreased. In this event, additional UL transmissions may be required for the hearability to be improved.

Embodiments of the present disclosure provide a scheme for multi-cell positioning, so as to at least in part solve the above and other potential problems. Some example embodiments of the present disclosure will be described below with reference to the figures. However, those skilled in the art would readily appreciate that the detailed description given herein with respect to these figures is for explanatory purpose as the present disclosure extends beyond theses limited embodiments.

<FIG> shows an example communication network <NUM> in which implementations of the present disclosure can be implemented. The communication network <NUM> includes a terminal device <NUM>, a serving network device <NUM> which provides a serving cell to serve the terminal device <NUM>, and a neighboring network device <NUM> which provides a neighbor cell. In the following, the neighboring network device <NUM> may be also referred to as a first network device, and the serving network device <NUM> may be also referred to as a second network device. It is to be understood that the number of network devices, terminal devices and/or cells is given for the purpose of illustration without suggesting any limitations to the present disclosure. The communication network <NUM> may include any suitable number of network devices, terminal devices and/or cells adapted for implementing implementations of the present disclosure.

As shown in <FIG>, the communication network <NUM> may also include a location server <NUM>, which is communicatively coupled with the terminal device <NUM>, the first network device <NUM> and the second network device <NUM>. The location server <NUM> is responsible for positioning different devices in the network <NUM>. For example, the location server <NUM> may be a physical or logical entity that collects measurements and other location information from terminal devices and network devices, and assists these devices in estimating their positions. The location server <NUM> may be a separate entity in a core network or be resided at a network device or a terminal device. In a LTE system, the location server <NUM> may include Evolved Serving Mobile Location Center (E-SMLC) and Secure User Plane Location (SUPL). In an NR system, the location server <NUM> may be a Location Management Function (LMF). Although the location server <NUM> is shown as a separate device from the devices <NUM>, <NUM> and <NUM>, it is to be understood that the location server <NUM> can also be implemented at one of the devices <NUM>, <NUM> and <NUM> in some embodiments.

Communications in the communication system <NUM> may be implemented according to any proper communication protocol(s), comprising, but not limited to, cellular communication protocols of the first generation (<NUM>), the second generation (<NUM>), the third generation (<NUM>), the fourth generation (<NUM>) and the fifth generation (<NUM>) and on the like, wireless local network communication protocols such as Institute for Electrical and Electronics Engineers (IEEE) <NUM> and the like, and/or any other protocols currently known or to be developed in the future. Moreover, the communication may utilize any proper wireless communication technology, comprising but not limited to: Code Divided Multiple Address (CDMA), Frequency Divided Multiple Address (FDMA), Time Divided Multiple Address (TDMA), Frequency Divided Duplexer (FDD), Time Divided Duplexer (TDD), Multiple-Input Multiple-Output (MIMO), Orthogonal Frequency Divided Multiple Access (OFDMA) and/or any other technologies currently known or to be developed in the future.

According to embodiments of the present disclosure, in order to determine the position of the terminal device <NUM>, the serving network device <NUM> may act as a relay for RTT (or propagation delay) estimation between the terminal device <NUM> and the neighboring network device <NUM>. In particular, the neighboring network device <NUM> may transmit a DL signal to the terminal device <NUM>, such that the terminal device <NUM> measures the receiving time of the DL signal. Then, the terminal device <NUM> may transmit an UL signal to the serving network device <NUM>, such that the serving network device <NUM> measures the receiving time of the UL signal. Finally, the serving network device <NUM> may transmit a signal to the neighboring network device <NUM>, such that the neighboring network device <NUM> measures the receiving time of the signal. The terminal device <NUM>, the serving network device <NUM> and the neighboring network device <NUM> may transmit their measurements to the location server <NUM>.

The location server <NUM> may estimate the RTT between the terminal device <NUM> and the neighboring network device <NUM> or propagation delay from the neighboring network device <NUM> to the terminal device <NUM> based on the measurements received from the terminal device <NUM>, the serving network device <NUM> and the neighboring network device <NUM>. Then, the location server <NUM> can use the estimated results for determining positioning information about the terminal device <NUM>.

As such, the number of hearable network devices in the network <NUM> can be increased. There is no need for the terminal device <NUM> to transmit an UL signal to the neighboring network device <NUM>. Therefore, the position accuracy can be improved without requiring large overhead or complex signaling. In addition, compared with other timing-based positioning techniques (such as, techniques based on Observed Time Difference of Arrival (OTDOA), or Uplink Time Difference of Arrival (UTDOA)), embodiments of the present disclosure do not suffer from synchronization errors.

<FIG> is a diagram illustrating a signaling procedure <NUM> in accordance with embodiments of the present disclosure. For the purpose of discussion, the signaling procedure <NUM> will be described with reference to <FIG>.

As shown in <FIG>, in order to determine positioning information about the terminal device <NUM>, the neighboring network device <NUM> may transmit <NUM> a RS (also referred to as "first RS") to the terminal device <NUM>. The terminal device <NUM> may receive the first RS from the neighboring network device <NUM> and determine the receiving time of the first RS. The terminal device <NUM> may transmit <NUM> a RS (also referred to as "third RS") to the serving network device <NUM>. The terminal device <NUM> may determine a time difference (also referred to as "second time difference") between the receiving time of the first RS and the transmitting time of the third RS, for example, which is represented as "t2" in <FIG>. The terminal device <NUM> may transmit information on the time difference t2 to the location server <NUM>, such that the location server <NUM> can determine the positioning information about the terminal device <NUM> at least based on the time difference t2.

The serving network device <NUM> may receive the third RS from the terminal device <NUM> and determine the receiving time of the third RS. The serving network device <NUM> may transmit <NUM> a RS (also referred to as "second RS") to the neighboring network device <NUM>.

In some embodiments, the second RS transmitted by the serving network device <NUM> may be a common signal for other purposes as well, such as a synchronization signal (SS). In some embodiments, the second RS transmitted by the serving network device may be beamformed, possibly in the direction of the neighboring network device. Alternatively, or in addition, in some embodiments, the second RS may be transmitted from the serving network device <NUM> to both of the terminal device <NUM> and the neighboring network device <NUM>. As will be described in the following with reference to <FIG>, the second RS transmitted from the serving network device <NUM> to the terminal device <NUM> can also be used to measure the RTT or propagation delay between the terminal device <NUM> and the serving network device <NUM>.

In some scenarios, for example, the network <NUM> may comprise a plurality of neighboring network devices (including but not limited to the neighboring network device <NUM>). In some embodiments, in this event, the second RS may be transmitted from the serving network device <NUM> to all of the plurality of neighboring network devices in the network <NUM>. Alternatively, in other embodiments, the second RS may be transmitted from the serving network device <NUM> to the neighboring network device <NUM> only if the neighboring network device <NUM> is unable to hear the UL signal from the terminal device <NUM> or the quality of the UL signal received from the terminal device <NUM> is below a predetermined threshold.

As shown in <FIG>, the serving network device <NUM> may determine a time difference (also referred to as "fourth time difference") between the receiving time of the third RS and the transmitting time of the second RS. For example, the fourth time difference may be represented as "t3" in <FIG>. The serving network device <NUM> may transmit information on the time difference t3 to the location server <NUM>, such that the location server <NUM> can determine the positioning information about the terminal device <NUM> at least based on the time difference t3.

The neighboring network device <NUM> may receive the second RS from the serving network device <NUM> and determine the receiving time of the second RS. The neighboring network device <NUM> may further determine a time difference (also referred to as "first time difference") between the transmitting time of the first RS and the receiving time of the second RS, for example, which is represented as "t4" in <FIG>. The neighboring network device <NUM> may transmit information on the time difference t4 to the location server <NUM>, such that the location server <NUM> can determine the positioning information about the terminal device <NUM> at least based on the time difference t4.

Once receiving the time difference t2 from the terminal device <NUM>, the time difference t3 from the serving network device <NUM> and the time difference t4 from the neighboring network device <NUM>, the location server <NUM> can estimate propagation delay from the neighboring network device <NUM> to the terminal device <NUM>, or the RTT between the neighboring network device <NUM> and the terminal device <NUM>.

In order to estimate the propagation delay from the neighboring network device <NUM> to the terminal device <NUM>, the location server <NUM> needs to determine propagation delay from the terminal device <NUM> to the serving network device <NUM> and propagation delay from the serving network device <NUM> to the neighboring network device <NUM>. In some embodiments, the positions of the serving network device <NUM> and the neighboring network device <NUM> may be already known at the location server <NUM>. In this event, the location server <NUM> can determine the propagation delay from the serving network device <NUM> to the neighboring network device <NUM> based on their positions. Additionally, the propagation delay from the terminal device <NUM> to the serving network device <NUM> can be determined through another signaling exchange procedure (such as, as shown in <FIG>).

<FIG> is a diagram illustrating a signaling procedure <NUM> in accordance with embodiments of the present disclosure. For the purpose of discussion, the signaling procedure <NUM> will be described with reference to <FIG>. The signaling procedure <NUM> may be used to determine the propagation delay or RTT between the terminal device <NUM> and the serving network device <NUM>.

As shown in <FIG>, the serving network device <NUM> may transmit <NUM> a RS (also referred to as "fourth RS") to the terminal device <NUM>. In some embodiments, the fourth RS transmitted from the serving network device <NUM> to the terminal device <NUM> and the second RS transmitted from the serving network device <NUM> to the neighboring network device <NUM> (shown by <NUM> in <FIG>) may be a same RS. Alternatively, in other embodiments, the fourth RS and the second RS may be different signals.

The terminal device <NUM> may receive the fourth RS from the serving network device <NUM> and determine the receiving time of the fourth RS. The terminal device <NUM> may transmit <NUM> a RS (also referred to as "fifth RS") to the serving network device <NUM>. In some embodiments, the fifth RS transmitted from the terminal device <NUM> to the serving network device <NUM> and the third RS the terminal device <NUM> to the serving network device <NUM> (shown by <NUM> in <FIG>) may be a same RS. Alternatively, in other embodiments, the fifth RS and the third RS may be different signals. The terminal device <NUM> may further determine a time difference (also referred to as "third time difference") between the receiving time of the fourth RS and the transmitting time of the fifth RS, for example, which is represented as "t1" in <FIG>.

The serving network device <NUM> may receive the fifth RS from the terminal device <NUM> and determine the receiving time of the fifth RS. The serving network device <NUM> may further determine a time difference (also referred to as "fifth time difference") between the transmitting time of the fourth RS and the receiving time of the fifth RS, for example, which is represented as "t5" in <FIG>.

The terminal device <NUM> may transmit information on the time difference t1 to the location server <NUM>. Also, the serving network device <NUM> may transmit information on the time difference t5 to the location server <NUM>. The location server <NUM> may estimate the RTT or propagation delay between the serving network device <NUM> and the terminal device <NUM> based on the time differences t1 and t5. For example, the RTT between the serving network device <NUM> and the terminal device <NUM> may be determined as (t5 - t1). The propagation delay from the terminal device <NUM> to the serving network device <NUM> may be determined as (t5 - t1) / <NUM>.

In some embodiments, the location server <NUM> may determine the propagation delay from the neighboring network device <NUM> to the terminal device <NUM> based on the time differences t1~t5 as well as the propagation delay (for example, represented as "t6") from the serving network device <NUM> to the neighboring network device <NUM>. For example, the propagation delay from the neighboring network device <NUM> to the terminal device <NUM> may be determined as (t4 - t3 - t2-t6- (t5-t1)/<NUM>). Alternatively, in some embodiments, the location server <NUM> may determine the RTT between the neighboring network device <NUM> and the terminal device <NUM> based on the time differences t1~t5 as well as the propagation delay t6 from the serving network device <NUM> to the neighboring network device <NUM>. For example, the RTT between the neighboring network device <NUM> and the terminal device <NUM> may be determined as (t4 - t3 - t2-t6- (t5-t1)/<NUM>) * <NUM>.

<FIG> is a diagram illustrating an overall signaling procedure <NUM> in accordance with embodiments of the present disclosure. For the purpose of discussion, the signaling procedure <NUM> will be described with reference to <FIG>. It is to be understood that the signaling sequence in <FIG> is shown only for the purpose of illustration, without suggesting any limitation to the present disclosure. In some embodiments, a different signaling sequence other than that as shown in <FIG> may be also applicable.

The positioning scheme according to embodiments of the present disclosure may be triggered or configured on demand. For example, in some embodiments, this positioning scheme may be triggered in response to the location server <NUM> receiving an indication of a high positioning accuracy requirement. Alternatively, in some embodiments, this positioning scheme may be triggered in response to the location server <NUM> receiving an indication that a neighboring network device in the network is unable to receive an UL signal from a terminal device or the quality of the UL signal received from the terminal device is below a predetermined threshold. Alternatively, in some embodiments, this positioning scheme may be triggered in response to the locations server <NUM> determining that the position accuracy needs to be improved.

As shown in <FIG>, in response to the positioning scheme being triggered, the location server <NUM> may transmit <NUM>, to the serving network device <NUM>, a request (also referred to as "third request") for RTT or propagation measurement. In response to receiving the third request, the serving network device <NUM> may perform corresponding operations as described above with reference to <FIG> and <FIG>.

Alternatively, or in addition, the location server <NUM> may also transmit <NUM>, to the serving network device <NUM>, assistance information (also referred to as "third assistance information"). In some embodiments, the third assistance information may include a configuration (also referred to as "fourth configuration") for transmitting the second RS from the serving network device <NUM> to the neighboring network device <NUM>. For example, the fourth configuration may indicate at least one of time information, frequency information, code information or spatial information about the transmission of the second RS. Additionally, the fourth configuration information may indicate the position of the neighbor network device <NUM>, such that the serving network device <NUM> may determine an optimal spatial direction for the transmission of the second RS. In response to receiving the third assistance information which indicates the fourth configuration, the serving network device <NUM> may transmit the second RS based on the fourth configuration. The serving network device <NUM> may also transmit, to the location server <NUM>, a response to the third request which indicates configuration information about the second RS. In some embodiments, in response to receiving the third request and the third assistance information, the serving network device <NUM> may respond to the location server <NUM> with the configuration information about the second RS. For example, the configuration information about the second RS may be determined either separately from the fourth configuration, or based on the fourth configuration and some additional parameters. Alternatively, or in addition, in some embodiments, the third assistance information may also indicate a configuration (also referred to as "fifth configuration") for reporting measurements, such as, a time window for reporting a time difference, a reporting periodicity, report accuracy of the time difference, or so on. In response to receiving the third assistance information indicating the fifth configuration, the serving network device <NUM> may report the time difference t3 and/or t5 based on the fifth configuration.

As shown in <FIG>, in response to the positioning scheme being triggered, the location server <NUM> may transmit <NUM>, to the terminal device <NUM>, a request (also referred to as "second request") for RTT or propagation measurement. In response to receiving the second request, the terminal device <NUM> may perform corresponding operations as described above with reference to <FIG> and <FIG>.

Alternatively, or in addition, the location server <NUM> may also transmit <NUM>, to the terminal device <NUM>, assistance information (also referred to as "second assistance information"). In some embodiments, the second assistance information may include a configuration (also referred to as "third configuration") for reporting measurements, such as, a time window for reporting a time difference, a reporting periodicity, report accuracy of the time difference, or so on. In response to receiving the second assistance information indicating the third configuration, the terminal device <NUM> may report the time difference t1 and/or t2 based on the third configuration.

As shown in <FIG>, in response to the positioning scheme being triggered, the location server <NUM> may transmit <NUM>, to the neighboring network device <NUM>, a request (also referred to as "first request") for RTT or propagation measurement. In response to receiving the first request, the neighboring network device <NUM> may perform corresponding operations as described above with reference to <FIG>.

Alternatively, or in addition, the location server <NUM> may also transmit <NUM>, to the neighboring network device <NUM>, assistance information (also referred to as "first assistance information"). In some embodiments, the first assistance information may include a configuration (also referred to as "first configuration") about the second RS. In some embodiments, the first configuration may comprise information for receiving the second RS. For example, the first configuration may indicate at least one of time information, frequency information, code information or spatial information about the transmission of the second RS. Additionally, the first configuration may also indicate beam-forming information of the serving network device <NUM> and/or the cell identity of the serving network device <NUM>. Alternatively or in addition, in some embodiments, the first configuration may comprise information for timing measurement based on the reception of the second RS. For example, the first configuration may indicate which algorithm to be used, the required accuracy and so on. In response to receiving the first assistance information indicating the first configuration and the first configuration comprising the information for receiving the second RS, the neighboring network device <NUM> may receive the second RS based on the first configuration. Additionally, in response to the first assistance information indicating the first configuration and the first configuration comprising the information for timing measurement, the neighboring network device <NUM> may determine the receiving time of the second RS based on the first configuration. Alternatively, or in addition, in some embodiments, the first assistance information may also indicate a configuration (also referred to as "second configuration") for reporting measurements, such as, a time window for reporting a time difference, a reporting periodicity, report accuracy of the time difference, or so on. In response to receiving the first assistance information indicating the second configuration, the neighboring network device <NUM> may report the time difference t4 based on the second configuration.

As shown in <FIG>, once the requests and/or assistance information are transmitted to the neighboring network device <NUM>, the terminal device <NUM> and the serving network device <NUM>, the signaling procedure <NUM> as shown in <FIG> may be performed. Then, the neighboring network device <NUM> may transmit <NUM>, to the location server <NUM>, information on the time difference t4 (for example, based on the first assistance information). The terminal device <NUM> may transmit <NUM>, to the location server <NUM>, information on the time difference t2 (for example, based on the second assistance information). The serving network device <NUM> may transmit <NUM>, to the location server <NUM>, information on the time difference t3 (for example, based on the third assistance information).

As shown in <FIG>, the signaling procedure <NUM> as shown in <FIG> may be performed. Then, the terminal device <NUM> may transmit <NUM>, to the location server <NUM>, information on the time difference t1 (for example, based on the second assistance information). The serving network device <NUM> may transmit <NUM>, to the location server <NUM>, information on the time difference t5 (for example, based on the third assistance information).

The location server <NUM> may determine the RTT or propagation delay between the neighboring network device <NUM> and the terminal device <NUM> based on the time differences t1~t5. Then, the location server <NUM> can determine the position of the terminal device <NUM> based on the determined RTT or propagation delay.

It can be seen from the above that, embodiments of the present disclosure provide a scheme for multi-cell positioning. The scheme enables the increased number of hearable network devices in the RTT scheme. Since more RTT measurements can be obtained, the position accuracy can be improved. In addition, there is no need for a terminal device to transmit an UL signal to a neighboring network device. Therefore, the scheme does not require large overhead or complex signaling. In addition, compared with other timing-based positioning techniques (such as, techniques based on OTDOA or UTDOA), embodiments of the present disclosure do not suffer from synchronization errors.

<FIG> illustrates a flowchart of a method <NUM> in accordance with embodiments of the present disclosure. The method <NUM> may be implemented at the neighboring network device <NUM> in the communication network <NUM>. It is to be understood that method <NUM> may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard.

At block <NUM>, the first network device <NUM> transmits a first RS to a terminal device served by a second network device.

At block <NUM>, the neighboring network device <NUM> receives a second RS from the second network device.

At block <NUM>, the neighboring network device <NUM> determines a first time difference between a time at which the first RS is transmitted and a time at which the second RS is received.

At block <NUM>, the neighboring network device <NUM> transmits information on the first time difference to a location server.

In some embodiments, transmitting the information on the first time difference comprises: in response to receiving a first request for positioning information from the location server, transmitting the information on the first time difference to the location server.

In some embodiments, the method <NUM> further comprises receiving first assistance information from the location server, the first assistance information indicating at least one of: a first configuration about the second RS, and a second configuration for reporting a time difference to the location server.

In some embodiments, receiving the second RS comprises: in response to the first assistance information indicating the first configuration and the first configuration comprising information for receiving the second RS, receiving the second RS based on the first configuration.

In some embodiments, determining the first time difference comprises: in response to the first assistance information indicating the first configuration and the first configuration comprising information for timing measurement, determining the time at which the second RS is received based on the first configuration.

In some embodiments, transmitting the information on the first time difference comprises: in response to the first assistance information indicating the second configuration, transmitting the information on the first time difference to the location server based on the second configuration.

<FIG> illustrates a flowchart of a method <NUM> in accordance with embodiments of the present disclosure. The method <NUM> may be implemented at the terminal device <NUM> in the communication network <NUM>. It is to be understood that method <NUM> may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard.

At block <NUM>, the terminal device <NUM> receives a first RS from a first network device.

At block <NUM>, the terminal device <NUM> transmits a third RS to a second network device serving the terminal device <NUM>.

At block <NUM>, the terminal device <NUM> determines a second time difference between a time at which the first RS is received and a time at which the third RS is transmitted.

At block <NUM>, the terminal device <NUM> transmits information on the second time difference to a location server.

In some embodiments, the method <NUM> further comprises: receiving a fourth RS from the second network device; transmitting a fifth RS to the second network device; determining a third time difference between a time at which the fourth RS is received and a time at which the fifth RS is transmitted; and transmitting information on the third time difference to the location server.

In some embodiments, the third RS and the fifth RS are the same RS.

In some embodiments, transmitting the information on the second time difference comprises: in response to receiving a second request for positioning information from the location server, transmitting the information on the second time difference to the location server.

In some embodiments, transmitting the information on the third time difference comprises: in response to receiving the second request from the location server, transmitting the information on the third time difference to the location server.

In some embodiments, the method <NUM> further comprises: receiving second assistance information from the location server, the second assistance information indicating a third configuration for reporting a time difference to the location server.

In some embodiments, transmitting the information on the second time difference comprises: transmitting the information on the second time difference to the location server based on the third configuration.

<FIG> illustrates a flowchart of a method <NUM> in accordance with embodiments of the present disclosure. The method <NUM> may be implemented at the serving network device <NUM> in the communication network <NUM>. It is to be understood that method <NUM> may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard.

At block <NUM>, the serving network device <NUM> receives, from a terminal device, a third RS at a second network device serving the terminal device.

At block <NUM>, the serving network device <NUM> transmits a second RS to a first network device.

At block <NUM>, the serving network device <NUM> determines a fourth time difference between a time at which the third RS is received and a time at which the second RS is transmitted.

At block <NUM>, the serving network device <NUM> transmits information on the fourth time difference to a location server.

In some embodiments, the method <NUM> further comprises: transmitting, from the second network device, a fourth RS to the terminal device; receiving a fifth RS from the terminal device; determining a fifth time difference between a time at which the fourth RS is transmitted and a time at which the fifth RS is received; and transmitting information on the fifth time difference to the location server.

In some embodiments, the fourth RS and the second RS are a same RS.

In some embodiments, transmitting the second RS comprises: in response to receiving from the location server a third request for positioning information, transmitting the second RS to the first network device; and transmitting, to the location server, a response comprising configuration information about the second RS.

In some embodiments, transmitting the second RS comprises: transmitting the second RS to the first network device by beam forming the second RS in a direction of the first network device.

In some embodiments, transmitting the information on the fourth time difference comprises: in response to receiving the third request from the location server, transmitting the information on the fourth time difference to the location server.

In some embodiments, transmitting the information on the fifth time difference comprises: in response to receiving the third request from the location server, transmitting the information on the fifth time difference to the location server.

In some embodiments, the method <NUM> further comprises receiving third assistance information from the location server, the third assistance information indicating at least one of: a fourth configuration for transmitting the second RS, and a fifth configuration for reporting a time difference to the location server.

In some embodiments, transmitting the second RS comprises: in response to the third assistance information indicating the fourth configuration, transmitting the second RS to the terminal device based on the fourth configuration.

In some embodiments, transmitting the information on the fourth time difference comprises: in response to the third assistance information indicating the fifth configuration, transmitting the information on the fourth time difference to the location server based on the fifth configuration.

<FIG> illustrates a flowchart of a method <NUM> in accordance with embodiments of the present disclosure. The method <NUM> may be implemented at the location server <NUM> in the communication network <NUM>. It is to be understood that method <NUM> may further include additional blocks not shown and/or omit some shown blocks, and the scope of the present disclosure is not limited in this regard.

At block <NUM>, the location server <NUM> obtains, from a first network device, information on a first time difference between a time at which the first network device transmits a first reference signal (RS) to a terminal device served by a second network device and a time at which the first network device receives a second RS from the second network device.

At block <NUM>, the location server <NUM> obtains, from the terminal device, information on a second time difference between a time at which the terminal device receives the first RS from the first network device and a time at which the terminal device transmits a third RS to the second network device.

At block <NUM>, the location server <NUM> obtains, from the second network device, information on a fourth time difference between a time at which the second network device receives the third RS from the terminal device and a time at which the second network device transmits the second RS to the first network device.

At block <NUM>, the location server <NUM> determines positioning information about the terminal device at least based on the first, second and fourth time differences.

In some embodiments, obtaining the information on the first time difference comprises: transmitting, to the first network device, a first request for positioning information; and in response to the first request being transmitted to the first network device, receiving the information on the first time difference from the first network device.

In some embodiments, the method <NUM> further comprises transmitting first assistance information to the first network device, the first assistance information indicating at least one of: a first configuration about the second RS, and a second configuration for reporting a time difference to the location server.

In some embodiments, obtaining the information on the first time difference comprises: in response to the first assistance information indicating the second configuration being transmitted, receiving the information on the first time difference from the first network device based on the second configuration.

In some embodiments, obtaining the information on the second time difference comprises: transmitting, to the terminal device, a second request for positioning information; and in response to the second request being transmitted to the terminal device, receiving the information on the second time difference from the terminal device.

In some embodiments, the method <NUM> further comprises: transmitting second assistance information to the terminal device, the second assistance information indicating a third configuration for reporting a time difference to the location server.

In some embodiments, obtaining the information on the second time difference comprises: receiving the information on the second time difference from the terminal device based on the third configuration.

In some embodiments, obtaining the information on the fourth time difference comprises: transmitting, to the second network device, a third request for positioning information; and in response to the third request being transmitted to the second network device, receiving the information on the fourth time difference from the second network device.

In some embodiments, the method <NUM> further comprises receiving a response to the third request from the second network device, the response indicating configuration information about the second reference signal.

In some embodiments, the method <NUM> further comprises transmitting third assistance information to the second network device, the third assistance information indicating at least one of: a fourth configuration for transmitting the second RS, and a fifth configuration for reporting a time difference to the location server.

In some embodiments, obtaining the information on the fourth time difference comprises: in response to the third assistance information indicating the fifth configuration being transmitted, receiving the information on the fourth time difference from the second network device based on the fifth configuration.

In some embodiments, determining the positioning information about the terminal device comprises: determining propagation delay from the first network device to the terminal device at least based on the first, second and fourth time differences.

In some embodiments, determining the positioning information about the terminal device comprises: determining a first round trip time (RTT) between the first network device and the terminal device at least based on the first, second and fourth time differences.

In some embodiments, determining the positioning information about the terminal device comprises: determining a second RTT between the terminal device and the second network device; and determining the positioning information about the terminal device based on the second RTT and the first, second and fourth time differences.

In some embodiments, determining the second RTT comprises: obtaining, from the terminal device, a third time difference between a time at which the terminal device receives a fourth RS from the second network device and a time at which the terminal device transmits a fifth RS to the second network device; obtaining, from the second network device, a fifth time difference between a time at which the second network device transmits the fourth RS to the terminal device and a time at which the second network device receives the fifth RS from the terminal device; and determining the second RTT between the terminal device and the second network device based on the third and fifth time differences.

In some embodiments, an apparatus capable of performing the method <NUM>, <NUM>, <NUM> and/or <NUM> may comprise means for performing respective steps of the method <NUM>, <NUM>, <NUM> and/or <NUM>. The means may be implemented in any suitable form. For example, the means may be implemented in a circuitry or software module.

In some embodiments, the means comprises at least one processor; and at least one memory including computer program code, the at least one memory and computer program code configured to, with the at least one processor, cause the performance of the apparatus.

In some embodiments, the apparatus capable of performing the method <NUM> comprises: means for transmitting, from a first network device, a first reference signal (RS) to a terminal device served by a second network device; means for receiving a second RS from the second network device; means for determining a first time difference between a time at which the first RS is transmitted and a time at which the second RS is received; and means for transmitting information on the first time difference to a location server.

In some embodiments, the means for transmitting the information on the first time difference comprises: means for in response to receiving a first request for positioning information from the location server, transmitting the information on the first time difference to the location server.

In some embodiments, the apparatus capable of performing the method <NUM> further comprises: means for receiving first assistance information from the location server, the first assistance information indicating at least one of: a first configuration about the second RS, and a second configuration for reporting a time difference to the location server.

In some embodiments, the means for receiving the second RS comprises: means for in response to the first assistance information indicating the first configuration and the first configuration comprising information for receiving the second RS, receiving the second RS based on the first configuration.

In some embodiments, the means for determining the first time difference comprises: means for in response to the first assistance information indicating the first configuration and the first configuration comprising information for timing measurement, determining the time at which the second RS is received based on the first configuration.

In some embodiments, the means for transmitting the information on the first time difference comprises: means for in response to the first assistance information indicating the second configuration, transmitting the information on the first time difference to the location server based on the second configuration.

In some embodiments, the apparatus capable of performing the method <NUM> comprises: means for receiving, at a terminal device, a first reference signal (RS) from a first network device; means for transmitting a third RS to a second network device serving the terminal device; means for determining a second time difference between a time at which the first RS is received and a time at which the third RS is transmitted; and means for transmitting information on the second time difference to a location server.

In some embodiments, the apparatus capable of performing the method <NUM> further comprises: means for receiving a fourth RS from the second network device; means for transmitting a fifth RS to the second network device; means for determining a third time difference between a time at which the fourth RS is received and a time at which the fifth RS is transmitted; and means for transmitting information on the third time difference to the location server.

In some embodiments, the means for transmitting the information on the second time difference comprises: means for in response to receiving a second request for positioning information from the location server, transmitting the information on the second time difference to the location server.

In some embodiments, the means for transmitting the information on the third time difference comprises: means for in response to receiving the second request from the location server, transmitting the information on the third time difference to the location server.

In some embodiments, the apparatus capable of performing the method <NUM> further comprises: means for receiving second assistance information from the location server, the second assistance information indicating a third configuration for reporting a time difference to the location server.

In some embodiments, the means for transmitting the information on the second time difference comprises: means for transmitting the information on the second time difference to the location server based on the third configuration.

In some embodiments, the apparatus capable of performing the method <NUM> comprises: means for receiving, from a terminal device, a third reference signal (RS) at a second network device serving the terminal device; means for transmitting a second RS to a first network device; means for determining a fourth time difference between a time at which the third RS is received and a time at which the second RS is transmitted; and means for transmitting information on the fourth time difference to a location server.

In some embodiments, the apparatus capable of performing the method <NUM> further comprises: means for transmitting, from the second network device, a fourth RS to the terminal device; receiving a fifth RS from the terminal device; means for determining a fifth time difference between a time at which the fourth RS is transmitted and a time at which the fifth RS is received; and means for transmitting information on the fifth time difference to the location server.

In some embodiments, the means for transmitting the second RS comprises: means for in response to receiving from the location server a third request for positioning information, transmitting the second RS to the first network device; and means for transmitting, to the location server, a response comprising configuration information about the second RS.

In some embodiments, the means for transmitting the second RS comprises: means for transmitting the second RS to the first network device by beam forming the second RS in a direction of the first network device.

In some embodiments, the means for transmitting the information on the fourth time difference comprises: means for in response to receiving the third request from the location server, transmitting the information on the fourth time difference to the location server.

In some embodiments, the means for transmitting the information on the fifth time difference comprises: means for in response to receiving the third request from the location server, transmitting the information on the fifth time difference to the location server.

In some embodiments, the apparatus capable of performing the method <NUM> further comprises means for receiving third assistance information from the location server, the third assistance information indicating at least one of: a fourth configuration for transmitting the second RS, and a fifth configuration for reporting a time difference to the location server.

In some embodiments, the means for transmitting the second RS comprises: means for in response to the third assistance information indicating the fourth configuration, transmitting the second RS to the terminal device based on the fourth configuration.

In some embodiments, the means for transmitting the information on the fourth time difference comprises: means for in response to the third assistance information indicating the fifth configuration, transmitting the information on the fourth time difference to the location server based on the fifth configuration.

In some embodiments, the apparatus capable of performing the method <NUM> comprises: means for obtaining, from a first network device, information on a first time difference between a time at which the first network device transmits a first reference signal (RS) to a terminal device served by a second network device and a time at which the first network device receives a second RS from the second network device; means for obtaining, from the terminal device, information on a second time difference between a time at which the terminal device receives the first RS from the first network device and a time at which the terminal device transmits a third RS to the second network device; means for obtaining, from the second network device, information on a fourth time difference between a time at which the second network device receives the third RS from the terminal device and a time at which the second network device transmits the second RS to the first network device; and means for determining positioning information about the terminal device at least based on the first, second and fourth time differences.

In some embodiments, the means for obtaining the information on the first time difference comprises: means for transmitting, to the first network device, a first request for positioning information; and means for in response to the first request being transmitted to the first network device, receiving the information on the first time difference from the first network device.

In some embodiments, the apparatus capable of performing the method <NUM> further comprises means for transmitting first assistance information to the first network device, the first assistance information indicating at least one of: a first configuration about the second RS, and a second configuration for reporting a time difference to the location server.

In some embodiments, the means for obtaining the information on the first time difference comprises: means for in response to the first assistance information indicating the second configuration being transmitted, receiving the information on the first time difference from the first network device based on the second configuration.

In some embodiments, the means for obtaining the information on the second time difference comprises: means for transmitting, to the terminal device, a second request for positioning information; and means for in response to the second request being transmitted to the terminal device, receiving the information on the second time difference from the terminal device.

In some embodiments, the apparatus capable of performing the method <NUM> further comprises: means for transmitting second assistance information to the terminal device, the second assistance information indicating a third configuration for reporting a time difference to the location server.

In some embodiments, the means for obtaining the information on the second time difference comprises: means for receiving the information on the second time difference from the terminal device based on the third configuration.

In some embodiments, the apparatus capable of performing the method <NUM> further comprises: means for transmitting, to the second network device, a third request for transmitting the second RS from the second network device to the first network device; and means for receiving a response to the third request from the second network device, the response indicating configuration information about the second RS.

In some embodiments, the means for obtaining the information on the fourth time difference comprises: means for transmitting, to the second network device, a third request for positioning information; and means for in response to the third request being transmitted to the second network device, receiving the information on the fourth time difference from the second network device.

In some embodiments, the apparatus capable of performing the method <NUM> further comprises means for receiving a response to the third request from the second network device, the response indicating configuration information about the second reference signal.

In some embodiments, the apparatus capable of performing the method <NUM> further comprises means for transmitting third assistance information to the second network device, the third assistance information indicating at least one of: a fourth configuration for transmitting the second RS, and a fifth configuration for reporting a time difference to the location server.

In some embodiments, the means for obtaining the information on the fourth time difference comprises: means for in response to the third assistance information indicating the fifth configuration being transmitted, receiving the information on the fourth time difference from the second network device based on the fifth configuration.

In some embodiments, the means for determining the positioning information about the terminal device comprises: means for determining propagation delay from the first network device to the terminal device at least based on the first, second and fourth time differences.

In some embodiments, the means for determining the positioning information about the terminal device comprises: means for determining a first RTT between the first network device and the terminal device at least based on the first, second and fourth time differences.

In some embodiments, the means for determining the positioning information about the terminal device comprises: means for determining a second RTT between the terminal device and the second network device; and means for determining the positioning information about the terminal device based on the second RTT and the first, second and fourth time differences.

In some embodiments, the means for determining the second RTT comprises: means for obtaining, from the terminal device, a third time difference between a time at which the terminal device receives a fourth RS from the second network device and a time at which the terminal device transmits a fifth RS to the second network device; means for obtaining, from the second network device, a fifth time difference between a time at which the second network device transmits the fourth RS to the terminal device and a time at which the second network device receives the fifth RS from the terminal device; and means for determining the second RTT between the terminal device and the second network device based on the third and fifth time differences.

<FIG> is a simplified block diagram of a device <NUM> that is suitable for implementing embodiments of the present disclosure. The device <NUM> may be used to implement the terminal device <NUM>, the neighboring network device <NUM>, the serving network device <NUM> or the location server as shown in <FIG>.

As shown, the device <NUM> includes a processor <NUM>, a memory <NUM> coupled to the processor <NUM>, a suitable transmitter (TX) and receiver (RX) <NUM> coupled to the processor <NUM>, and a communication interface coupled to the TX/RX <NUM>. The memory <NUM> stores at least a part of a program <NUM>. The TX/RX <NUM> is for bidirectional communications. The TX/RX <NUM> has at least one antenna to facilitate communication, though in practice an Access Node mentioned in this application may have several ones.

The program <NUM> is assumed to include program instructions that, when executed by the associated processor <NUM>, enable the device <NUM> to operate in accordance with the implementations of the present disclosure, as discussed herein with reference to <FIG>. The implementations herein may be implemented by computer software executable by the processor <NUM> of the device <NUM>, or by hardware, or by a combination of software and hardware. The processor <NUM> may be configured to implement various implementations of the present disclosure. Furthermore, a combination of the processor <NUM> and memory <NUM> may form processing means <NUM> adapted to implement various implementations of the present disclosure.

The memory <NUM> may be of any type suitable to the local technical network and may be implemented using any suitable data storage technology, such as a non-transitory computer readable storage medium, semiconductor based memory devices, magnetic memory devices and systems, optical memory devices and systems, fixed memory and removable memory, as non-limiting examples. While only one memory <NUM> is shown in the device <NUM>, there may be several physically distinct memory modules in the device <NUM>. The processor <NUM> may be of any type suitable to the local technical network, and may include one or more of general purpose computers, special purpose computers, microprocessors, digital signal processors (DSPs) and processors based on multicore processor architecture, as non-limiting examples.

The components included in the apparatuses and/or devices of the present disclosure may be implemented in various manners, including software, hardware, firmware, or any combination thereof. In one embodiment, one or more units may be implemented using software and/or firmware, for example, machine-executable instructions stored on the storage medium. In addition to or instead of machine-executable instructions, parts or all of the units in the apparatuses and/or devices may be implemented, at least in part, by one or more hardware logic components. For example, and without limitation, illustrative types of hardware logic components that can be used include Field-programmable Gate Arrays (FPGAs), Application-specific Integrated Circuits (ASICs), Application-specific Standard Products (ASSPs), System-on-a-chip systems (SOCs), Complex Programmable Logic Devices (CPLDs), and the like.

The present disclosure also provides at least one computer program product tangibly stored on a non-transitory computer readable storage medium. The computer program product includes computer-executable instructions, such as those included in program modules, being executed in a device on a target real or virtual processor, to carry out the method <NUM> as described above with reference to <FIG>, the method <NUM> as described above with reference to <FIG>, the method <NUM> as described above with reference to <FIG> and/or the method <NUM> as described above with reference to <FIG>. Generally, program modules include routines, programs, libraries, objects, classes, components, data structures, or the like that perform particular tasks or implement particular abstract data types. The functionality of the program modules may be combined or split between program modules as desired in various embodiments. Machine-executable instructions for program modules may be executed within a local or distributed device. In a distributed device, program modules may be located in both local and remote storage media.

Examples of the carrier include a signal, computer readable media.

For the purpose of the present disclosure as described herein above, it should be noted that,.

Claim 1:
A method comprising:
transmitting (<NUM>), from a first network device, a first reference signal to a terminal device served by a second network device;
receiving (<NUM>), at the first network device (<NUM>), a second reference signal from the second network device;
determining (<NUM>), at the first network device (<NUM>), a first time difference between a time at which the first reference signal is transmitted and a time at which the second reference signal is received; and
transmitting (<NUM>), from the first network device (<NUM>), information on the first time difference to a location server.