WO2025211994A1

WO2025211994A1 - Positioning of user equipment

Info

Publication number: WO2025211994A1
Application number: PCT/SE2024/050302
Authority: WO
Inventors: Thomas Johansson; Grzegorz NAGLER; Nhung Hong BUI
Original assignee: Telefonaktiebolaget LM Ericsson AB
Current assignee: Telefonaktiebolaget LM Ericsson AB
Priority date: 2024-04-03
Filing date: 2024-04-03
Publication date: 2025-10-09
Anticipated expiration: 2026-10-03

Abstract

There is provided techniques for positioning of a user equipment. A method is performed by a location management device. The method comprises obtaining a trigger for a positioning procedure to be performed for the user equipment. The method comprises sending a measurement information message to an access network node for the access network node to perform the positioning procedure for the user equipment. The measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment.

Description

POSITIONING OF USER EQUIPMENT

TECHNICAL FIELD

Embodiments presented herein relate to methods, a location management device, an access network node, computer programs, and a computer program product for positioning of a user equipment.

BACKGROUND

In 3GPP TS 23.273, “5G System (5GS) Location Services (LCS)”, version 18.4.0, is described how Location Services (LCS) clients can request positioning estimates of user equipment (UE) served by the network. It is further described how an Access and Mobility Management Function (AMF) can trigger positioning requests for emergency calls, for example. In this respect, the LCS client interacts with an LCS server for the purpose of obtaining location information for one or more UEs.

Fig. 1 is a schematic diagram illustrating a cellular communication network 100 where embodiments presented herein can be applied. The cellular communication network 100 represents a reference architecture of a fifth-generation telecommunication system (5GS). However, it is appreciated that similar, or corresponding, entities, are part of also other network architectures, and the herein disclosed embodiments are not limited to the specific network architecture illustrated in Fig. 1. The cellular communication network 100 represents an architectural reference model for 5GS LCS for a UE in a reference point representation. In general terms, the cellular communication network 100 comprises a core network and a (radio) access network ((R)AN). The (R)AN comprises one or more (radio) access nodes configured to provide network access to its served UEs. The UEs are there by enabled access to a data network (not shown), e.g., providing operator services, Internet access or 3rd party services to the UEs. The (R)AN and the core network are interconnected with each other. The core network comprises the following entities relevant for positioning: an AMF, an Application Function (AF), a Gateway Mobile Location Centre (GMLC), an LCS client, a Location Management Function (LMF), a Location Retrieval Function (LRF), a Network Exposure Function (NEF), and a Unified Data Management UDM node. Interfaces, or reference points, are represented by the format Xy (e.g. Ni, N2, ..., NL2, .., Le, etc.). It is understood that the architectural reference model might comprise further functions and interfaces. In general terms, The LMF is configured to decide on which positioning procedure to use. Further, the LMF might request measurements from the (R)AN via the NL1 and N2 reference points. The requests are in this case supported by the New Radio Positioning Protocol A (NRPPa) as run between the LMF and the (R)AN. In this context, according to the Enhanced Cell Identity (E-CID) procedure in 3GPP TS 38 455? “NR Positioning Protocol A (NRPPa)”, version 18.0.0, different measurements such as Timing Advance (TA) and Angle-of- Arrival (AoA) can be requested.

Further, an Information Element (IE) denoted “Measurement Characteristics Request Indicator” can be used to request several types of measurements to be report, such as Line-of-Sight (LoS) or Non-Line-of-Sight (NLoS) indication, AoA per path. In addition, it can be indicated if one measurement shall be reported (by the measurements being requested on-demand) or if several measurements shall be reported (by periodic measurements being requested). If periodic measurements are requested, the measurement periodicity is indicated as well. The E-CID procedure is triggered per UE context.

A general signalling diagram for an NRPPa E-CID based procedure to trigger an on- demand measurement is shown in Fig. 2.

Si: The LMF 200 sends a measurement initiation request message to a (radio) access network node 300 in the (R)AN. In the present example, the (radio) access network node 300 is exemplified by a gNB. The measurement initiation request message requests positioning measurements to be performed for a given UE 400.

In further detail, a Positioning Information Exchange procedure, a Positioning Activation Procedure, and a Measurement procedure can be performed between the LMF 200 and the (radio) access network node 300 in step Si. The Positioning Information Exchange procedure and the Positioning Activation Procedure are used to exchange information about the uplink reference signal configuration in terms of whether periodic measurements, a-periodic measurements, or semi-persistent measurements are to be reported. The (radio) access network node 300 might then configure the given UE 400 accordingly. The Measurement procedure is used to request the (radio) access network node 300 to start the positioning measurements. S2: The (radio) access network node 300, in case there is no uplink signal, such as an uplink reference signal, from the given UE 400 for the (radio) access network node 300 to measure on, schedules the given UE 400 to either transmit a random access signal or one or more instances of an uplink reference signal. If the given UE 400 is already configured with periodic uplink reference signals, step S2 can be skipped.

S3: The given UE 400 transmits the random access signal or uplink reference signal as scheduled by the (radio) access network node 300. The (radio) access network node 300 performs measurements on the random access signal or uplink reference signal as transmitted by the given UE 400.

S4: The (radio) access network node 300 transmits a measurement report of the measurements to the LMF 200. In case a message denoted “Measurement Report” is used, an IE denoted ”TRP Measurement Result” can be used to comprise the actual measurements.

As for the measurements on the uplink reference signal, when the E-CID procedure is used, the (radio) access network node might decide to use either random access signals, sounding reference signals (SRSs) or demodulation reference signals (DMRSs) to measure on. Hence, the bandwidth of the uplink reference signal, and thus the accuracy of the measurement, may vary.

In general terms, selecting between using Random Access Signals, SRSs, and DMRSs for positioning purposes involves evaluating their distinct characteristics and tradeoffs. Each type of signal has its own advantages and limitations when it comes to positioning accuracy, system complexity, and resource efficiency.

Random Access signals are primarily designed for initiating communication between the UEs and the network. While Random Access signals can be used for rough positioning, their sporadic nature and the design optimized for access rather than accuracy can limit their precision for positioning purposes. Further, a high demand on the random access channel, especially in densely populated areas, can lead to collisions and reduced performance, thus affecting the positioning accuracy. Further, resources for Random Access signals are limited. On the other hand, SRSs are primarily designed for measuring channel conditions, allowing for high-precision positioning. However, SRSs require dedicated resource allocation, which can lead to inefficiencies in bandwidth usage, especially if the network is heavily loaded with data traffic. Hence, the availability of SRS resources is limited. Implementing SRS-based positioning might require more complex system configurations and algorithmic solutions to interpret the signal accurately, compared to using Random Access signals for positioning. Using SRSs for positioning purposes might therefore lead to increased computational requirements and potential delays.

DMRS are used within the context of data transmission for channel estimation and demodulation. Their utility for positioning is limited to the area where data communication is actively occurring, which might not be suitable for wide-area positioning tasks. Since DMRS are closely tied to data channels, their effectiveness for positioning can be compromised by signal interference and multipath effects, particularly in urban environments.

The above disclosed different examples of signals, based on which the measurements can be made, will thus have different impacts on normal traffic latency and system throughput.

In view of the above, there is a need for positioning procedures that reduce the impact on normal traffic latency and system throughput.

SUMMARY

An object of embodiments herein is to enable positioning of a user equipment where the positioning procedure does not suffer from the above issues, or where the above issues at least are mitigated or reduced.

A particular object is to enable positioning of a user equipment where the positioning procedure impacts the normal traffic latency or system throughput in a minimum way.

According to a first aspect there is presented a method for positioning of a user equipment. The method is performed by a location management device. The method comprises obtaining a trigger for a positioning procedure to be performed for the user equipment. The method comprises sending a measurement information message to an access network node for the access network node to perform the positioning procedure for the user equipment. The measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment.

According to a second aspect there is presented a location management device for positioning of a user equipment, the location management device comprises processing circuitry. The processing circuitry is configured to cause the location management device to obtain a trigger for a positioning procedure to be performed for the user equipment. The processing circuitry is configured to cause the location management device to send a measurement information message to an access network node for the access network node to perform the positioning procedure for the user equipment. The measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment.

According to a third aspect there is presented a location management device for positioning of a user equipment. The location management device comprises an obtain module configured to obtain a trigger for a positioning procedure to be performed for the user equipment. The location management device comprises a send module configured to send a measurement information message to an access network node for the access network node to perform the positioning procedure for the user equipment. The measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment.

According to a fourth aspect there is presented a computer program for positioning of a user equipment. The computer program comprises computer code which, when run on processing circuitry of a location management device, causes the location management device to perform actions. One action comprises the location management device to obtain a trigger for a positioning procedure to be performed for the user equipment. One action comprises the location management device to send a measurement information message to an access network node for the access network node to perform the positioning procedure for the user equipment. The measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment. According to a fifth aspect there is presented a method for positioning of a user equipment. The method is performed by an access network node. The method comprises receiving a measurement information message from a location management device for the access network node to perform a positioning procedure for the user equipment. The measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment. The method comprises performing the positioning procedure for the user equipment in accordance with the measurement information message.

According to a sixth aspect there is presented an access network node for positioning of a user equipment, the access network node comprises processing circuitry. The processing circuitry is configured to cause the access network node to receive a measurement information message from a location management device for the access network node to perform a positioning procedure for the user equipment. The measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment. The processing circuitry is configured to cause the access network node to perform the positioning procedure for the user equipment in accordance with the measurement information message.

According to a seventh aspect there is presented an access network node for positioning of a user equipment. The access network node comprises a receive module configured to receive a measurement information message from a location management device for the access network node to perform a positioning procedure for the user equipment. The measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment. The access network node comprises a position module configured to perform the positioning procedure for the user equipment in accordance with the measurement information message.

According to an eighth aspect there is presented a computer program for positioning of a user equipment. The computer program comprises computer code which, when run on processing circuitry of an access network node, causes the access network node to perform actions. One action comprises the access network node to receive a measurement information message from a location management device for the access network node to perform a positioning procedure for the user equipment. The measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment. One action comprises the access network node to perform the positioning procedure for the user equipment in accordance with the measurement information message.

According to a ninth aspect there is presented a computer program product comprising a computer program according to at least one of the fourth aspect and the eighth aspect and a computer readable storage medium on which the computer program is stored. The computer readable storage medium could be a non-transitory computer readable storage medium.

Advantageously, these aspects enable the location management device to select configuration parameters, in terms expected response time and accuracy, of the positioning procedure to reduce the impact on normal traffic latency and system throughput.

Advantageously, these aspects enable the access network node to have access to information about the expected response time and accuracy of the positioning procedure of the UE.

In this way, the access network node is enabled to select uplink signals for the UE to transmit, as well as the scheduling of the selected uplink signals, such that the impact as caused by the positioning procedure on the normal traffic latency and system throughput is reduced.

Other objectives, features and advantages of the enclosed embodiments will be apparent from the following detailed disclosure, from the attached dependent claims as well as from the drawings.

Generally, all terms used in the claims are to be interpreted according to their ordinary meaning in the technical field, unless explicitly defined otherwise herein. All references to "a/an/the element, apparatus, component, means, module, step, etc." are to be interpreted openly as referring to at least one instance of the element, apparatus, component, means, module, step, etc., unless explicitly stated otherwise. The steps of any method disclosed herein do not have to be performed in the exact order disclosed, unless explicitly stated.

BRIEF DESCRIPTION OF THE DRAWINGS

The inventive concept is now described, by way of example, with reference to the accompanying drawings, in which:

Fig. 1 is a schematic diagram illustrating a cellular communication network according to an example;

Fig. 2 is a signalling diagram of a method according to an example;

Figs. 3 and 4 are flowcharts of methods according to embodiments;

Figs. 5 and 6 are signalling diagrams of methods according to embodiments;

Fig. 7 is a schematic diagram showing structural units of a location management device according to an embodiment;

Fig. 8 is a schematic diagram showing functional modules of a location management device according to an embodiment;

Fig. 9 is a schematic diagram showing structural units of an access network node according to an embodiment;

Fig. 10 is a schematic diagram showing functional modules of an access network node according to an embodiment; and

Fig. 11 shows one example of a computer program product comprising computer readable means according to an embodiment.

DETAILED DESCRIPTION

The inventive concept will now be described more fully hereinafter with reference to the accompanying drawings, in which certain embodiments of the inventive concept are shown. This inventive concept may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the inventive concept to those skilled in the art. Like numbers refer to like elements throughout the description. Any step or feature illustrated by dashed lines should be regarded as optional.

As disclosed above, there is a need for positioning procedures that reduce the impact on normal traffic latency and system throughput.

In further detail, the impact on normal traffic latency and system throughput can be regarded as a trade-off between accuracy, latency, and resource consumption for the positioning procedure. Achieving high positioning accuracy often requires more signal resources and processing power, which can increase latency and reduce overall system efficiency.

For example, SRS resources may be used for multiple-input multiple-output (MIMO) communication, and hence during MIMO communication the SRS can be used also for positioning purposes, at little signalling overhead, as the SRSs are anyway scheduled for the MIMO communication. However, if the demand for MIMO communication is low, scheduling SRSs for positioning purposes might generate significant signalling overhead, and thus negatively impact the normal network traffic. In such cases, positioning based on DMRS might be preferred to minimize the impact on normal network traffic, at least for some of the UEs.

In further detail, when scheduling uplink transmissions, priorities might be used to select what uplink transmission type (such as data transmission or positioning) to prioritize. If a given uplink transmission type is given low priority, any uplink transmission of this given uplink transmission type might be delayed. For some positioning purposes this might be acceptable whereas for other positioning purposes this might not be acceptable.

In any case, for the aforementioned NRPPa E-CID procedure illustrated in Fig. 2, there is not any information from the LMF that can aid the (radio) access network node in its decision regarding which type of uplink signal the UE should transmit during the positioning procedure, nor is there any information regarding the scheduling priority of the positioning procedure. The herein disclosed embodiments are therefore based on providing the (radio) access network node with information (in terms of expected accuracy and response time of the positioning procedure) so that the (radio) access network node can select uplink signals for the UE to transmit, as well as the scheduling of the selected uplink signals, such that the positioning procedure causes as little impact on the normal traffic latency and system throughput as needed (for the given expected accuracy and response time of the positioning procedure).

Reference is now made to Fig. 3 illustrating a method for positioning of a user equipment as performed by the location management device 200 according to an embodiment.

S102: The location management device 200 obtains a trigger for a positioning procedure to be performed for the user equipment.

S104: The location management device 200 sends a measurement information message to the access network node 300 for the access network node 300 to perform the positioning procedure for the user equipment. The measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment.

In general terms, the indication of response time and/or accuracy might be either explicit or implicit. Different indications of response time and accuracy will be disclosed below.

Embodiments relating to further details of positioning of a user equipment as performed by the location management device 200 will now be disclosed with continued reference to Fig. 3.

There could be different entities from which the trigger is obtained in step S102. In some embodiments, the trigger is obtained from either an LCS client or from an AMF device. Further, the indication of response time and accuracy might by the location management device 200 be derived from information in the trigger, that is, in some embodiments, the trigger comprises information based on which the indication of response time and accuracy is derived. For example, in case the trigger is received from the AMF device, the trigger might indicate that the user equipment has initiated an emergency call. This information might indicate both a short response time and a high accuracy of the positioning procedure for the user equipment.

Aspects of the indication of response time and accuracy of the positioning procedure for the user equipment will be disclosed next.

In general terms, the indication of response time and accuracy of the positioning procedure might be sent in an IE. The information in this IE might this indicate the expected accuracy and response time to aid the access network node in selecting scheduling priority and selecting between different uplink signals, such as random access signals, DMRSs, and SRSs, to be used during the positioning procedure for the user equipment. In this respect, an SRS configuration indicated by the location management device 200 is an example of an implicit indication of accuracy as it specifies bandwidth and other resources. Hence, no other accuracy indication is needed in this case. Further, with respect to configurations of periodic and semi- persistent SRSs, such a configuration by itself is an example of an implicit indication of response time as the periodicity implicitly gives information to the scheduler about priority. Hence, no other response time indication is needed in this case.

As is understood, the response time indicates the urgency of the positioning procedure (i.e., how soon in time the positioning procedure needs to be performed). There could be different indications of the response time. In some non-limiting examples, the response time is in the measurement information message indicated by at least one of: a time value (in the range 1 to 128), a time unit (in terms of seconds, ten seconds, or ten milliseconds), a value range in seconds for the response time, a flag, an indication to use best effort.

As is understood, the accuracy indicates how accurate the positioning procedure needs to be (i.e., at which level of granularity the position of the user equipment needs to be obtained, measured, estimated, determined, or predicted). There could be different indications of the accuracy. In some non-limiting examples, the accuracy is in the measurement information message indicated by at least one of: type of uplink signal to be used during the positioning procedure, bandwidth to be used during the positioning procedure, a value range in meters for the accuracy, an indication to use best effort. There could be different types of measurement information message in which the indication of response time and accuracy of the positioning procedure for the user equipment is sent. In some embodiments, the measurement information message is either a measurement initiation request message or a positioning activation request message.

There could be different types of positioning procedures. In some non-limiting examples, the positioning procedure is, or is part of, an NRPPa procedure, an Fl Application Protocol (F1AP) procedure, and/or an E-CID procedure. In general terms, the E-CID procedures over NRPPa are the same as over F1AP.

There could be different access network nodes 300 to which the measurement information message is sent. In some aspects, the access network node 300 to which the measurement information message is sent is the serving access network node of the user equipment. That is, in some embodiments, the measurement initiation request message is sent to the access network node 300 holding the UE context of the user equipment. However, in other embodiments, the measurement initiation request message is sent to an access network node that is not the serving access network node for the user equipment and that thus does not hold the UE context of the user equipment.

In general terms, and as will be disclosed in further detail below, once the access network node 300 has received the measurement information message, the access network node 300 performs the positioning procedure for the user equipment in accordance with the measurement information message. The access network node 300 might then report a measurement result of the positioning procedure for the user equipment to the location management device 200. Therefore, in some embodiments, the location management device 200 is configured to perform (optional) step S106.

S106: The location management device 200 receives a measurement response message from the access network node 300. The measurement response message comprises a measurement result of the positioning procedure for the user equipment. Reference is now made to Fig. 4 illustrating a method for positioning of a user equipment as performed by the access network node 300 according to an embodiment.

As disclosed above, the location management device 200 in step S104 sends a measurement information message. It is here assumed that the access network node 300 receives this measurement information message.

S202: The access network node 300 receives a measurement information message from the location management device 200 for the access network node 300 to perform a positioning procedure for the user equipment. The measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment.

S204: The access network node 300 performs the positioning procedure for the user equipment in accordance with the measurement information message.

Embodiments relating to further details of positioning of a user equipment as performed by the access network node 300 will now be disclosed with continued reference to Fig. 4.

Aspects of the indication of response time of the positioning procedure for the user equipment will be disclosed next.

In some aspects, the access network node 300, based on the indication of response time, decides on scheduling and/or prioritization of the positioning procedure. That is, in some embodiments, performing the positioning procedure in step S204 comprises determining scheduling of the positioning procedure in accordance with the indication of response time.

As disclosed above, there could be different indications of the response time. As further disclosed above, in some non-limiting examples, the response time is in the measurement information message indicated by at least one of: a time value (in the range 1 to 128), a time unit (in terms of seconds, ten seconds, or ten milliseconds), a value range in seconds for the response time, a flag, an indication to use best effort. For example, when the response time is indicated to be shorter than some threshold value (hereinafter referred to as a first threshold value), then the access network node 300 is to give high priority to the positioning procedure. That is, in some embodiments, when the value range is lower than a first threshold value, the positioning procedure is prioritized during the scheduling. In some non-limiting examples, the first threshold value is in the range 0.5 seconds to 1.5 seconds.

For example, when the response time is indicated to be longer than some threshold value (e.g., the first threshold value) but shorter than some other threshold (hereinafter referred to as a second threshold value), then the access network node 300 is to initially give low priority to the positioning procedure but to give high priority to the positioning procedure after a time duration given by the second threshold value. That is, in some embodiments, when the value range is higher than a first threshold value but lower than a second threshold value, the positioning procedure is not prioritized (i.e., given low priority) during the scheduling until a timer defined by the first threshold value has passed, and then given high priority. In some non-limiting examples, the second threshold value is in the range 4.5 seconds to 5.5 seconds.

For example, when the flag time flag indicates low latency, then the access network node 300 is to give high priority to the positioning procedure. That is, in some embodiments, when the flag indicates low latency, the positioning procedure is prioritized (i.e., given high priority) during the scheduling, likewise, when the flag time flag does not indicate low latency, then the access network node 300 is to give low priority to the positioning procedure.

For example, when the response time is given by the indication to use best effort, the positioning procedure is not prioritized (i.e., given low priority) during the scheduling.

Aspects of the indication of accuracy of the positioning procedure for the user equipment will be disclosed next.

In some aspects, the access network node 300, based on the indication of accuracy, decides which type of uplink signals that is to be used during the positioning procedure. That is, in some embodiments, performing the positioning procedure in step S204 comprises determining type of uplink signals to be used during the positioning procedure in accordance with the indication of accuracy.

As disclosed above, there could be different indications of the accuracy. As further disclosed above, in some non-limiting examples, the accuracy is in the measurement information message indicated by at least one of: type of uplink signal to be used during the positioning procedure, bandwidth to be used during the positioning procedure, a value range in meters for the accuracy, an indication to use best effort.

For example, when the accuracy indicates that SRSs are to be used, the access network node 300 uses one of the supported SRS configurations during the positioning procedure.

That is, in some embodiments, when the type of uplink signal indicates SRSs to be used, the access network node 300 selects among available SRS configurations to be used during the positioning procedure.

For example, when best effort is to be used, the access network node 300 uses one of the supported SRS configurations or one of the supported DMRS configurations during the positioning procedure. The used SRS configuration or DMRS configuration might then be a SRS configuration or DMRS configuration that is already used by the user equipment. That is, in some embodiments, when the accuracy is given by the indication to use best effort, the access network node 300 selects among available SRS configurations and/or among available DMRS configurations to be used during the positioning procedure.

In accordance with what has already been disclosed, there could be different types of measurement information message in which the indication of response time and accuracy of the positioning procedure for the user equipment is received. In some embodiments, the measurement information message is either a measurement initiation request message or a positioning activation request message.

In accordance with what has already been disclosed, there could be different types of positioning procedures. In some non-limiting examples, the positioning procedure is, or is part of, an NRPPa procedure, an F1AP procedure, and/or an E-CID procedure. The measurements over FiAP can be regarded as a subset of the measurements in NRPPa but where the measurements are performed in a distributed unit of the access network node 300.

In accordance with what has already been disclosed, there could be different access network nodes 300 that receive the measurement information message. In some embodiments, the access network node 300 holds the UE context of the user equipment (and is thus the serving access network node 300 of this user equipment). However, in other embodiments, the access network node is not the serving access network node for the user equipment, and thus does not hold the UE context of the user equipment.

In some aspects, the access network node 300 reports a measurement result of the positioning procedure for the user equipment to the location management device 200. Therefore, in some embodiments, the access network node 300 is configured to perform (optional) step S206.

S206: The access network node 300 sends a measurement response message to the location management device 200. The measurement response message comprises a measurement result of the positioning procedure for the user equipment.

Further aspects of the measurement information message will be disclosed next.

In Table 1 is provided an example of IES that could be included in the measurement information message as sent from the location management device 200 to the access network node 300 for the access network node to perform the positioning procedure for the user equipment. As disclosed above, this message could be either an E-CID measurement initiation request message or a positioning activation request message. In Table 1, “O” in the column “Presence” is short for “optional”.

Table 1: IES included in measurement information message

A first particular embodiment for positioning of a UE based on at least some of the above disclosed embodiments will now be disclosed in detail with reference to the signalling diagram of Fig. 5. In this embodiment, the measurement information message is an E-CID measurement initiation request message, the location management device 200 is an LMF, and the access network node 300 is a gNB.

S301: The location management device 200 sends an E-CID measurement initiation request message to an access network node 300 in the (R)AN. The E-CID measurement initiation request message requests positioning measurements to be performed for a given UE 400. The E-CID measurement initiation request message comprises an indication of response time and accuracy of the positioning procedure for the UE 400.

S302: The access network node 300 performs the positioning procedure for the UE 400 in accordance with the indication of response time and accuracy in the E-CID measurement initiation request message. The access network node 300 schedules the given UE 400 with one or more uplink signals in accordance with the indication of response time and accuracy.

S303: The given UE 400 transmits one or more uplink signals in accordance with the scheduling. The access network node 300 performs positioning measurements on the one or more uplink signals as transmitted by the given UE 400.

S304: The access network node 300 transmits a measurement report of the measurements to the location management device 200 in an E-CID measurement initiation response message. A second particular embodiment for positioning of a UE based on at least some of the above disclosed embodiments will now be disclosed in detail with reference to the signalling diagram of Fig. 6. In this embodiment, the measurement information message is a positioning activation request message, the location management device 200 is an LMF, and the access network node 300 is a gNB.

S401: The location management device 200 sends a positioning information request message to an access network node 300 in the (R)AN. The positioning information request message indicates that the resource type is a-periodic SRS.

S402: The access network node 300 sends a positioning information response message to the location management device 200. The positioning information response message indicates at least one available SRS configuration for a-periodic SRS transmission.

S403: The location management device 200 sends a positioning activation request message to the access network node 300. The positioning activation request message comprises an indication of response time and accuracy of the positioning procedure for the UE 400.

S404: The access network node 300 transmits the system frame number and slot number to the location management device 200 in positioning activation response message.

S405: The location management device 200 sends a measurement request message for the UE 400 to the access network node 300.

S406: The access network node 300 performs the positioning procedure for the UE 400 in accordance with the indication of response time and accuracy in the positioning activation request message. The access network node 300 schedules the given UE 400 with one or more a-periodic SRS resources and decides on the scheduling time (in terms of system frame number and slot number), in accordance with the indication of response time and accuracy.

S407: The given UE 400 transmits an uplink signal in terms of one or more SRS resource in accordance with the scheduling. The access network node 300 performs measurements on the one or more SRS resource as transmitted by the given UE 400. S408: The access network node 300 sends a measurement response message to the location management device 200. The measurement response message comprises a measurement report of the measurements for the UE 400. In the measurement report, an IE denoted ”TRP Measurement Result” can be used to comprise the actual measurements.

Fig. 7 schematically illustrates, in terms of a number of structural units, the components of a location management device 200 according to an embodiment. Processing circuitry 210 is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 1110a (as in Fig. 11), e.g. in the form of a storage medium 230. The processing circuitry 210 may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

Particularly, the processing circuitry 210 is configured to cause the location management device 200 to perform a set of operations, or steps, as disclosed above. For example, the storage medium 230 may store the set of operations, and the processing circuitry 210 may be configured to retrieve the set of operations from the storage medium 230 to cause the location management device 200 to perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus the processing circuitry 210 is thereby arranged to execute methods as herein disclosed.

The storage medium 230 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory.

The location management device 200 may further comprise a communications (comm.) interface 220 for communications with other entities, functions, nodes, and devices, such as in Fig. 1. As such the communications interface 220 may comprise one or more transmitters and receivers, comprising analogue and digital components. The processing circuitry 210 controls the general operation of the location management device 200 e.g. by sending data and control signals to the communications interface 220 and the storage medium 230, by receiving data and reports from the communications interface 220, and by retrieving data and instructions from the storage medium 230. Other components, as well as the related functionality, of the location management device 200 are omitted in order not to obscure the concepts presented herein.

Fig. 8 schematically illustrates, in terms of a number of functional modules, the components of a location management device 200 according to an embodiment. The location management device 200 of Fig. 8 comprises a number of functional modules; an obtain module 210a configured to perform step S102, and a send module 210b configured to perform step S104. The location management device 200 of Fig. 8 may further comprise a number of optional functional modules, such as a receive module 210c configured to perform step S106. In general terms, each functional module 2ioa:2ioc maybe implemented in hardware or in software. Preferably, one or more or all functional modules 2ioa:2ioc may be implemented by the processing circuitry 210, possibly in cooperation with the communications interface 220 and/or the storage medium 230. The processing circuitry 210 may thus be arranged to from the storage medium 230 fetch instructions as provided by a functional module 210a: 210c and to execute these instructions, thereby performing any steps of the location management device 200 as disclosed herein.

The location management device 200 may be provided as a standalone device or as a part of at least one further device. For example, the location management device 200 may be provided in a node of the core network. Alternatively, functionality of the location management device 200 may be distributed between at least two devices, or nodes. These at least two nodes, or devices, may either be part of the same network part (such as the (radio) access network or the core network) or may be spread between at least two such network parts. A first portion of the instructions performed by the location management device 200 may be executed in a first device, and a second portion of the instructions performed by the location management device 200 may be executed in a second device; the herein disclosed embodiments are not limited to any particular number of devices on which the instructions performed by the location management device 200 may be executed. Hence, the methods according to the herein disclosed embodiments are suitable to be performed by a location management device 200 residing in a cloud computational environment. Therefore, although a single processing circuitry 210 is illustrated in Fig. 9 the processing circuitry 210 maybe distributed among a plurality of devices, or nodes. The same applies to the functional modules 210a: 210c of Fig. 8 and the computer program 1120a of Fig. 11.

Fig. 9 schematically illustrates, in terms of a number of structural units, the components of an access network node 300 according to an embodiment. Processing circuitry 310 is provided using any combination of one or more of a suitable central processing unit (CPU), multiprocessor, microcontroller, digital signal processor (DSP), etc., capable of executing software instructions stored in a computer program product 1110b (as in Fig. 11), e.g. in the form of a storage medium 330. The processing circuitry 310 may further be provided as at least one application specific integrated circuit (ASIC), or field programmable gate array (FPGA).

Particularly, the processing circuitry 310 is configured to cause the access network node 300 to perform a set of operations, or steps, as disclosed above. For example, the storage medium 330 may store the set of operations, and the processing circuitry 310 may be configured to retrieve the set of operations from the storage medium 330 to cause the access network node 300 to perform the set of operations. The set of operations may be provided as a set of executable instructions. Thus the processing circuitry 310 is thereby arranged to execute methods as herein disclosed.

The storage medium 330 may also comprise persistent storage, which, for example, can be any single one or combination of magnetic memory, optical memory, solid state memory or even remotely mounted memory.

The access network node 300 may further comprise a communications interface 320 for communications with other entities, functions, nodes, and devices, such as in Fig. 1. As such the communications interface 320 may comprise one or more transmitters and receivers, comprising analogue and digital components.

The processing circuitry 310 controls the general operation of the access network node 300 e.g. by sending data and control signals to the communications interface 320 and the storage medium 330, by receiving data and reports from the communications interface 320, and by retrieving data and instructions from the storage medium 330. Other components, as well as the related functionality, of the access network node 300 are omitted in order not to obscure the concepts presented herein.

Fig. 10 schematically illustrates, in terms of a number of functional modules, the components of an access network node 300 according to an embodiment. The access network node 300 of Fig. 10 comprises a number of functional modules; a receive module 310a configured to perform step S202, and a position module 310b configured to perform step S204. The access network node 300 of Fig. 10 may further comprise a number of optional functional modules, such a send module 310c configured to perform step S206. In general terms, each functional module 3100:3100 may be implemented in hardware or in software. Preferably, one or more or all functional modules 3100:3100 may be implemented by the processing circuitry 310, possibly in cooperation with the communications interface 320 and/or the storage medium 330. The processing circuitry 310 may thus be arranged to from the storage medium 330 fetch instructions as provided by a functional module 3100:3100 and to execute these instructions, thereby performing any steps of the access network node 300 as disclosed herein. The access network node 300 might either be a gNB, a node B (NB), an enhanced node B (eNB), an integrated access and backhaul (IAB) node, an access point, a transmission and reception point, etc.

Some (radio) access network architectures define access network nodes comprising multiple component parts or nodes: a central unit (CU), one or more distributed units (DUs), and one or more radio units (RUs). The protocol layer stack of the network node is divided between the CU, the DUs and the RUs, with one or more lower layers of the stack implemented in the RUs, and one or more higher layers of the stack implemented in the CU and/or DUs. The CU is coupled to the DUs via a fronthaul higher layer split (HLS) network; the CU/DUs are connected to the RUs via a fronthaul lower-layer split (LLS) network. The DU may be combined with the CU in some embodiments, where a combined DU/CU may be referred to as a CU or simply a baseband unit. A communication link for communication of user data messages or packets between the RU and the baseband unit, CU, or DU is referred to as a fronthaul network or interface. Messages or packets may be transmitted from the access network node 300 in the downlink (i.e. , from the CU to the RU) or received by the access network node 300 in the uplink (i.e., from the RU to the CU).

Fig. 11 shows one example of a computer program product 1110a, 1110b comprising computer readable means 1130. On this computer readable means 1130, a computer program 1120a can be stored, which computer program 1120a can cause the processing circuitry 210 and thereto operatively coupled entities and devices, such as the communications interface 220 and the storage medium 230, to execute methods according to embodiments described herein. The computer program 1120a and/or computer program product 1110a may thus provide means for performing any steps of the location management device 200 as herein disclosed. On this computer readable means 1130, a computer program 1120b can be stored, which computer program 1120b can cause the processing circuitry 310 and thereto operatively coupled entities and devices, such as the communications interface 320 and the storage medium 330, to execute methods according to embodiments described herein. The computer program 1120b and/or computer program product 1110b may thus provide means for performing any steps of the access network node 300 as herein disclosed. In the example of Fig. 11, the computer program product 1110a, 1110b is illustrated as an optical disc, such as a CD (compact disc) or a DVD (digital versatile disc) or a Blu- Ray disc. The computer program product 1110a, 1110b could also be embodied as a memory, such as a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), or an electrically erasable programmable read-only memory (EEPROM) and more particularly as a non-volatile storage medium of a device in an external memory such as a USB (Universal Serial Bus) memory or a Flash memory, such as a compact Flash memory. Thus, while the computer program 1120a, 1120b is here schematically shown as a track on the depicted optical disk, the computer program 1120a, 1120b can be stored in any way which is suitable for the computer program product 1110a, 1110b.

The inventive concept has mainly been described above with reference to a few embodiments. However, as is readily appreciated by a person skilled in the art, other embodiments than the ones disclosed above are equally possible within the scope of the inventive concept, as defined by the appended patent claims.

Claims

1. A method for positioning of a user equipment, wherein the method is performed by a location management device (200), and wherein the method comprises: obtaining (S102) a trigger for a positioning procedure to be performed for the user equipment; and sending (S104) a measurement information message to an access network node (300) for the access network node (300) to perform the positioning procedure for the user equipment, wherein the measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment.

2. The method according to claim 1, wherein the positioning procedure is, or is part of, a New Radio Positioning Protocol A, NRPPa, procedure, an Fl Application Protocol, F1AP, procedure, or an enhanced cell identity, E-CID, procedure.

3. The method according to claim 1 or 2, wherein the measurement initiation request message is sent to the access network node (300) holding a UE context of the user equipment.

4. The method according to any preceding claim, wherein the measurement information message is either a measurement initiation request message or a positioning activation request message.

5. The method according to any preceding claim, wherein the response time is in the measurement information message indicated by at least one of: a time value, a time unit, a value range in seconds for the response time, a flag, an indication to use best effort.

6. The method according to any preceding claim, wherein the accuracy is in the measurement information message indicated by at least one of: type of uplink signal to be used during the positioning procedure, bandwidth to be used during the positioning procedure, a value range in meters for the accuracy, an indication to use best effort.

7. The method according to any preceding claim, wherein the trigger is obtained from either a localization service client or from an access and mobility function device.

8. The method according to any preceding claim, wherein the trigger comprises information based on which the indication of response time and accuracy is derived.

9. The method according to any preceding claim, wherein the method further comprises: receiving (S106) a measurement response message from the access network node (300), wherein the measurement response message comprises a measurement result of the positioning procedure for the user equipment.

10. A method for positioning of a user equipment, wherein the method is performed by an access network node (300), and wherein the method comprises: receiving (S202) a measurement information message from a location management device (200) for the access network node (300) to perform a positioning procedure for the user equipment, wherein the measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment; and performing (S204) the positioning procedure for the user equipment in accordance with the measurement information message.

11. The method according to claim 10, wherein the positioning procedure is, or is part of, a New Radio Positioning Protocol A, NRPPa, procedure, an Fl Application Protocol, F1AP, procedure, or an enhanced cell identity, E-CID, procedure.

12. The method according to claim 10 or 11, wherein the access network node (300) holds a UE context of the user equipment.

13. The method according to any of claims 10 to 12, wherein the measurement information message is either a measurement initiation request message or a positioning activation request message. 14- The method according to any of claims 10 to 13, wherein performing the positioning procedure comprises determining scheduling of the positioning procedure in accordance with the indication of response time.

15. The method according to any of claims 10 to 14, wherein the response time is in the measurement information message indicated by at least one of: a time value, a time unit, a value range in seconds for the response time, a flag, an indication to use best effort.

16. The method according to claim 15, wherein the value range is lower than a first threshold value, and wherein the positioning procedure is prioritized during the scheduling.

17. The method according to claim 15, wherein the value range is higher than a first threshold value but lower than a second threshold value, and wherein the positioning procedure is not prioritized during the scheduling until a timer defined by the first threshold value has passed.

18. The method according to claim 15, wherein the flag indicates low latency, and wherein the positioning procedure is prioritized during the scheduling.

19. The method according to claim 15, wherein the response time is given by the indication to use best effort, and wherein the positioning procedure is not prioritized during the scheduling.

20. The method according to any of claims 10 to 19, wherein performing the positioning procedure comprises determining type of uplink signals to be used during the positioning procedure in accordance with the indication of accuracy.

21. The method according to any of claims 10 to 20, wherein the accuracy is in the measurement information message indicated by at least one of: type of uplink signal to be used during the positioning procedure, bandwidth to be used during the positioning procedure, a value range in meters for the accuracy, an indication to use best effort.

22. The method according to claim 21, wherein the type of uplink signal indicates sounding reference signals, SRSs, to be used, and wherein the access network node "2-1

(300) selects among available SRS configurations to be used during the positioning procedure.

23. The method according to claim 21, wherein the accuracy is given by the indication to use best effort, and wherein the access network node (300) selects among available sounding reference signal, SRS, configurations and/or among available demodulation reference signal, DMRS, configurations to be used during the positioning procedure.

24. The method according to any of claims 10 to 23, wherein the method further comprises: sending (S206) a measurement response message to the location management device (200), wherein the measurement response message comprises a measurement result of the positioning procedure for the user equipment.

25. A location management device (200) for positioning of a user equipment, the location management device (200) comprising processing circuitry (210), the processing circuitry being configured to cause the location management device (200) to: obtain a trigger for a positioning procedure to be performed for the user equipment; and send a measurement information message to an access network node (300) for the access network node (300) to perform the positioning procedure for the user equipment, wherein the measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment.

26. A location management device (200) for positioning of a user equipment, the location management device (200) comprising: an obtain module (210a) configured to obtain a trigger for a positioning procedure to be performed for the user equipment; and a send module (210b) configured to send a measurement information message to an access network node (300) for the access network node (300) to perform the positioning procedure for the user equipment, wherein the measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment.

27. The location management device (200) according to claim 25 or 26, further being configured to perform the method according to any of claims 2 to 9.

28. An access network node (300) for positioning of a user equipment, the access network node (300) comprising processing circuitry (310), the processing circuitry being configured to cause the access network node (300) to: receive a measurement information message from a location management device (200) for the access network node (300) to perform a positioning procedure for the user equipment, wherein the measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment; and perform the positioning procedure for the user equipment in accordance with the measurement information message.

29. An access network node (300) for positioning of a user equipment, the access network node (300) comprising: a receive module (310a) configured to receive a measurement information message from a location management device (200) for the access network node (300) to perform a positioning procedure for the user equipment, wherein the measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment; and a position module (310b) configured to perform the positioning procedure for the user equipment in accordance with the measurement information message.

30. The access network node (300) according to claim 28 or 29, further being configured to perform the method according to any of claims 11 to 24.

31. A computer program (1120a) for positioning of a user equipment, the computer program comprising computer code which, when run on processing circuitry (210) of a location management device (200), causes the location management device (200) to: obtain (S102) a trigger for a positioning procedure to be performed for the user equipment; and send (S104) a measurement information message to an access network node (300) for the access network node (300) to perform the positioning procedure for the user equipment, wherein the measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment.

32. A computer program (1120b) for positioning of a user equipment, the computer program comprising computer code which, when run on processing circuitry (310) of an access network node (300), causes the access network node (300) to: receive (S202) a measurement information message from a location management device (200) for the access network node (300) to perform a positioning procedure for the user equipment, wherein the measurement information message comprises an indication of response time and accuracy of the positioning procedure for the user equipment; and perform (S204) the positioning procedure for the user equipment in accordance with the measurement information message.

33. A computer program product (1110a, 1110b) comprising a computer program (1120a, 1120b) according to at least one of claims 31 and 32, and a computer readable storage medium (1130) on which the computer program is stored.