Determining switching behavior based on estimated sensing performance

Abstract

A system (1) is configured to collect measurements of candidate cells (41, 42) and estimate communication performance for each candidate cell based on the measurements. The candidate cells include the current cell (41) serving a mobile device (31). The system is further configured to estimate sensing performance for each candidate cell, identify the optimal cell for serving the mobile device from the candidate cells based on the estimated communication performance and the estimated sensing performance, and cause the mobile device to switch from the current cell to the optimal cell if it is determined that the current cell is not the optimal cell, and / or cause the mobile device not to switch from the current cell to another cell if it is determined that the current cell is the optimal cell.

Description

Technical Field

[0001] The present invention relates to a system for determining the best cell for serving a mobile device from a plurality of candidate cells, including the current cell serving the mobile device. The invention also relates to a base station for receiving handover instructions and a mobile device for reporting events to the base station currently serving the mobile device.

[0002] The present invention further relates to a method for determining the best cell for serving a mobile device from a plurality of candidate cells, including the current cell serving the mobile device. The present invention also relates to a method for receiving a handover instruction and a method for reporting events to the base station currently serving the mobile device.

[0003] The present invention also relates to computer program products that enable computer systems to perform such methods. Background Technology

[0004] 6G network technology is envisioned to natively facilitate both communication and sensing services under the collective names JCAS ('Joint Communication and Sensing') or ISAC ('Integrated Sensing and Communication'), combining solutions that enable resource-efficient support of the requirements imposed by either service type. The paper "Enabling Joint Communication and Radar Sensing in Mobile Networks - A Survey" by JA Zhang et al. in the first quarter of 2022, IEEE Communications Surveys & Tutorials (vol. 24, no. 1, pp. 306-345), provides an investigation into different technologies for implementing JCAS / ISAC.

[0005] In this context, the term sensing generally refers to the detection and / or tracking of target objects that may or may not be connected to (or can be connected to) a mobile network in a communicative sense. Use cases include real-time object detection for autonomous driving, home intruder detection, UAV detection, UAV flight control / coordination, and real-time monitoring including high-precision positioning of objects for industrial applications. Target objects can have different attributes such as shape, size, speed, distance, position, orientation, material type, color, temperature, heartbeat, pitch, yaw, and / or roll.

[0006] During sensing, a distinction is made between monitoring and tracking modes. In monitoring mode, the purpose of sensing is to detect the presence of a target object, typically involving detecting one or more of the object's attributes, such as its location. In tracking mode, the purpose of sensing is to follow the trajectory of the sensed target object, usually requiring estimation of the object's velocity, its changes, and its direction of movement.

[0007] For example, a base station (BS) and / or a conventional mobile device (i.e., a UE (User Equipment)) can be used as a JCAS node. For instance, the base station can communicate with a conventional mobile device while simultaneously sensing / detecting one or more objects. During sensing, at least one JCAS node transmits a radio signal that may be affected by one or more nearby objects. The signal may be received by at least one JCAS node. If so, the received signal reflects the influence of one or more objects on the transmitted wireless communication signal being affected by one or more objects, and can be processed to detect properties of these objects, such as those mentioned above.

[0008] JCAS / ISAC may need to directly share resources such as antennas, spectrum, and timing in an 'orthogonal' sense, i.e., dedicating such resources to one service type or another. Alternatively, a given signal can be used to support both types of services simultaneously, for example, when the reflection of communication signals is also utilized for sensing purposes such as the presence or movement of an object. In the latter scenario, each mobile device connects to the cell expected to provide optimal communication performance (i.e., mobile device and cell pairing). Sensing can then be achieved using existing mobile device and cell pairings. However, these pairings may make it more difficult to achieve the desired sensing performance because the latter is not considered in the device-cell pairing decision. Note that, in general, a UE can be paired (associated) with multiple cells simultaneously. Summary of the Invention

[0009] The first object of the present invention is to provide a system that, when using communication signals for sensing purposes, makes it possible to achieve a better trade-off between communication performance and sensing performance.

[0010] A second object of the present invention is to provide a method that, when using communication signals for sensing purposes, makes it possible to achieve a better trade-off between communication performance and sensing performance.

[0011] In a first aspect of the invention, a system for determining the optimal cell for serving a mobile device from a plurality of candidate cells (the plurality of candidate cells including a current cell serving the mobile device) includes at least one processor configured to: collect measurements of the plurality of candidate cells; estimate communication performance for each of the plurality of candidate cells based on the measurements; estimate sensing performance for each of the plurality of candidate cells; identify the optimal cell for serving the mobile device from the plurality of candidate cells based on the estimated communication performance and the estimated sensing performance; and if it is determined that the current cell is not the optimal cell, cause the mobile device to switch from the current cell to the optimal cell; and / or if it is determined that the current cell is the optimal cell, cause the mobile device not to switch from the current cell to another cell. For example, the measurements may include a received signal strength indicator and / or cell load.

[0012] Compared to traditional inter-cell handover for communication tasks, the aforementioned system can implement 'JCAS active handover' or 'JCAS blocked handover' to enhance support for sensing services. By enhancing traditional inter-cell handover for communication tasks with 'JCAS active handover' and 'JCAS blocked handover', communication signals can be reused for sensing purposes, and a better trade-off is achieved between communication performance and sensing performance. This system can be used to achieve improved sensing performance without sacrificing or at an acceptable level of communication performance. Depending on operator policies, the performance or efficiency of the communication link may be sacrificed to some extent if doing so would enhance sensing performance.

[0013] Traditional communication task handover (such as 4G / 5G network handover) does not consider the performance of the sensing task. The usefulness of the transmissions associated with a given communication task in aiding the sensing task depends, for example, on the directionality of such transmissions, which is determined by the serving cell and the applied service beam, which are traditionally optimized purely from the perspective of the communication session. Therefore, whether the resulting service beam is useful for the current sensing task is merely a result of this communication session-oriented optimization.

[0014] 'JCAS active handover' intentionally alters the connection between the mobile device and the cell, thereby changing the sensing topology (the set of nodes participating in the sensing task). 'JCAS prevent handover' prevents changes in the connection between the mobile device and the cell, thereby preventing changes in the sensing topology that would normally occur during a conventional handover process.

[0015] The aforementioned system enables the selection of serving cells, applied service beams, and utilized resources to be more generally JCAS-oriented, rather than purely session-specific. This means that, for example, the serving cell and applied service beam for a given communication call can be optimized to provide the best options from the combined perspective of both communication and sensing tasks. Even the characteristics of the communication signal (e.g., the directivity, width, and transmit power of the transmission beam) can be optimized from the perspective of combined communication and sensing.

[0016] When estimating communication performance, one can estimate only the communication performance experienced by the mobile device in question, or one can estimate the communication performance experienced by other devices. This allows for consideration of the performance impact of potential handovers on other UE sessions. When estimating sensing performance, this can address one or more sensing tasks that may utilize (or be subject to interference from) current and / or candidate new beams sent to the mobile device in question.

[0017] At least one processor may be configured to: collect measurements of a plurality of candidate cells by collecting measurements of a plurality of candidate reference beams, each of the plurality of candidate reference beams being associated with one of the plurality of candidate cells; estimate communication performance for each of the plurality of candidate cells by estimating communication performance for each of the plurality of candidate reference beams based on the measurements; estimate sensing performance for each of the plurality of candidate cells by estimating sensing performance for each of the plurality of candidate reference beams; identify an optimal reference beam from the plurality of candidate reference beams based on the estimated communication performance and the estimated sensing performance for the plurality of candidate reference beams; and identify an optimal cell for serving a mobile device by determining the cell associated with the optimal reference beam.

[0018] For example, multiple candidate reference beams can consist of one or more of the strongest reference beams from each candidate cell. For instance, in the case of 5G, candidate reference beams could include synchronization signal block beams. For the current serving cell (which is among the candidate cells), communication performance can also be estimated based on the actual service beams and / or experienced performance, rather than solely on the reference beams. In addition to measurements of candidate reference beams, estimations of sensing performance can also utilize contributions from other signals such as service beams.

[0019] By estimating communication and sensing performance for multiple beams in a candidate cell, a better trade-off between communication and sensing performance can be achieved. For example, when considering these services separately, using a particular service beam may not produce optimal communication performance and may not produce optimal sensing performance, but it can still provide an optimal trade-off between communication and sensing performance. It is particularly advantageous for the system to identify the optimal reference beam from multiple candidate reference beams if at least one processor is configured to instruct the mobile device to identify the optimal reference beam or to cause the cell / base station to instruct the mobile device to identify the optimal reference beam. If the reference beam identified by the system as the optimal reference beam will not or may not be automatically selected when the cell of this reference beam is selected (and the service beam corresponding to the optimal reference beam will therefore not be automatically assigned to the mobile device), the mobile device can be instructed to identify the optimal reference beam (to its base station) or the cell / base station can be caused to instruct the mobile device to identify the optimal reference beam (to its base station) to ensure that the optimal reference beam is actually selected.

[0020] At least one processor can be configured to: adjust the communication performance estimated for multiple candidate reference beams based on beam differences between multiple candidate reference beams and their corresponding service beams, and identify the optimal reference beam from the multiple candidate reference beams based on the estimated sensing performance for the multiple candidate reference beams and the adjusted communication performance. By considering the beam differences between candidate reference beams for which measurements are obtained and service beams for which measurements are not obtained but are intended for communication tasks, communication performance can be estimated more accurately. For example, the additional beamforming gain of a narrower service beam can be considered in this way compared to a wider SSB (reference) beam.

[0021] At least one processor may be configured to: collect measurements of a plurality of candidate cells by collecting measurements of a plurality of reference beams; and derive one or more recommended service beams based on the measurements of the reference beams, each of the plurality of recommended service beams being associated with one of the plurality of candidate cells; estimate communication performance for each of the plurality of candidate cells by estimating communication performance for each of the plurality of recommended service beams based on the measurements; estimate sensing performance for each of the plurality of candidate cells by estimating sensing performance for each of the plurality of recommended service beams; identify the optimal service beam from the plurality of recommended service beams based on the estimated communication performance and the estimated sensing performance for the plurality of recommended service beams; and identify the optimal cell for serving the mobile device by determining the cell associated with the optimal service beam. For example, in the case of 5G, the reference beam may include a Channel State Information Reference Signal (CSI-RS) beam.

[0022] At least one processor can be configured to: determine the contribution of traffic beam usage to sensing performance, the traffic beam being used by a base station in the current cell to serve a mobile device; determine whether the contribution exceeds a threshold; and, if the contribution does not exceed the threshold, identify the optimal cell for serving the mobile device based on communication performance and sensing performance; and, if the current cell is determined not to be the optimal cell, cause the mobile device to hand over from the current cell to the optimal cell. 'JCAS active handover' is not performed in response to conventional triggering, hence the term "active". For example, the contribution of traffic beam usage to (e.g., implemented by all node pairs for a sensing task) (overall) sensing performance can be estimated based on reference beam measurements.

[0023] Because determining the contribution of active / current traffic beam usage to sensing performance can be performed relatively quickly and purely on the network side, it does not require consuming any potentially scarce transmission or processing / energy resources of the mobile device. Since identifying the optimal cell does consume potentially scarce processing / energy resources of the mobile device and involves a measurement / reporting process that requires even more time and transmission resource usage, it is beneficial to do so only if the contribution does not exceed a threshold.

[0024] At least one processor may be configured to: when it is determined that a mobile device has reported an event indicating that another cell has become better than the current cell in terms of communication performance, identify the best cell for serving the mobile device, the event being reported to the base station currently serving the mobile device; and if it is determined that the current cell is the best cell (i.e., in terms of combined communication and sensing performance), cause the mobile device not to switch from the current cell to the other cell.

[0025] For example, in response to a conventional trigger: a reported event indicating that another cell has become better than the current cell in terms of communication performance, 'JCAS prevents handover' is performed. If such an event would normally trigger a handover, then if it is determined that the current cell is the best cell (i.e., the cell estimated to provide the best combination of sensing and communication performance), this handover can be prevented. For example, multiple candidate cells could include only the current cell and other cells.

[0026] At least one processor can be configured to prevent a mobile device from switching from its current cell to another by instructing the base station not to perform a handover in response to an event reported to the base station. This is advantageous if it is not the base station that identifies the best cell, for example, if the system is isolated from any base station.

[0027] At least one processor may be configured to: obtain an operator policy specifying weights; assign weights to communication performance and / or to sensing performance; and identify the optimal cell for serving the mobile device based on the weighted communication performance and / or weighted sensing performance. For example, this enables non-trivial weighting of potentially conflicting aspects related to communication quality, sensing quality, and resource efficiency.

[0028] In a second aspect of the invention, a base station for receiving a handover instruction includes at least one processor serving a mobile device, the at least one processor being configured to: receive a handover instruction identifying the mobile device; and perform a handover of the mobile device to an optimal cell specified in the handover instruction, and / or, if the handover instruction indicates that the mobile device should not be handed over to another cell, not perform a handover of the mobile device in response to an event reported to the base station indicating that the other cell has become better than the mobile device's current cell in terms of communication performance.

[0029] In a third aspect of the invention, a mobile device for reporting events to a base station currently serving the mobile device includes at least one processor configured to: report an event to the base station currently serving the mobile device, the event indicating that another cell has become better than the current cell of the mobile device in terms of communication performance; and receive a response to the reported event from the base station; and, within a predetermined amount of time, either postpone reporting any new event indicating that another cell has become better than the current cell of the mobile device in terms of communication performance, or adjust one or more thresholds used to determine whether another cell has become better than the current cell of the mobile device in terms of communication performance.

[0030] For example, once a handover request from the current serving cell A to the target cell B is rejected, the mobile device will avoid considering cell B as a handover target for the next five seconds. However, the network can decide that downlink beams are only needed for another two seconds, after which it will happily support the mobile device's handover from cell A to cell B. The proposed protection solution allows the network to instruct the mobile device to avoid sending new handover requests for the next two seconds (which is possible unless it risks losing connectivity entirely). The benefit is that the mobile device does not need to consume any energy / processing / transmission resources for measuring candidate cells and generating / submitting handover requests. Additionally, assuming the desired target cell remains unchanged, the UE can connect to its desired target cell faster (after two seconds instead of five seconds), and the UE can therefore experience improved connectivity / QoS. Note that there are several scenario variations, such as regarding default / instructed UE behavior and what might be the best candidate cell after a given time period.

[0031] In a fourth aspect of the invention, a method for determining an optimal cell for serving a mobile device from a plurality of candidate cells (the plurality of candidate cells including a current cell serving the mobile device) includes: collecting measurements of the plurality of candidate cells; estimating communication performance for each of the plurality of candidate cells based on the measurements; estimating sensing performance for each of the plurality of candidate cells; identifying an optimal cell for serving the mobile device from the plurality of candidate cells based on the estimated communication performance and the estimated sensing performance for the plurality of candidate cells; and if it is determined that the current cell is not the optimal cell, causing the mobile device to switch from the current cell to the optimal cell, and / or if it is determined that the current cell is the optimal cell, causing the mobile device not to switch from the current cell to another cell. The method may be performed by software running on a programmable device. Such software may be provided as a computer program product.

[0032] In a fifth aspect of the invention, a method of receiving a handover instruction includes: receiving a handover instruction that identifies a mobile device; and performing a handover of the mobile device to an optimal cell specified in the handover instruction, and / or performing a handover of the mobile device without responding to an event reported to a base station if the handover instruction indicates that the mobile device should not be handed over to another cell, the event indicating that another cell has become better than the mobile device's current cell. The method may be performed by software running on a programmable device. Such software may be provided as a computer program product.

[0033] In a sixth aspect of the invention, a method of reporting an event to a base station currently serving a mobile device includes: reporting an event to the base station indicating that another cell has become better than the current cell of the mobile device in terms of communication performance; and receiving a response to the reported event from the base station; and reporting any new event indicating that the other cell has become better than the current cell of the mobile device in terms of communication performance, either within a predetermined amount of time or by delaying the reporting, or by adjusting one or more thresholds used to determine whether the other cell has become better than the current cell of the mobile device in terms of communication performance. The method may be performed by software running on a programmable device. Such software may be provided as a computer program product.

[0034] In addition, a computer program for performing the methods described herein, and a non-transitory computer-readable storage medium for storing the computer program are provided. For example, the computer program may be downloaded from an existing device or uploaded to an existing device, or the computer program may be stored during the manufacture of these systems.

[0035] A non-transitory computer-readable storage medium stores at least a first software code portion, which, when executed or processed by a computer, is configured to perform executable operations for determining the best cell for serving a mobile device from a plurality of candidate cells, including the current cell serving the mobile device.

[0036] The executable operations include: collecting measurements of a plurality of candidate cells; estimating communication performance for each of the plurality of candidate cells based on the measurements; estimating sensing performance for each of the plurality of candidate cells; identifying the optimal cell for serving the mobile device from the plurality of candidate cells based on the estimated communication performance and the estimated sensing performance for the plurality of candidate cells; and causing the mobile device to switch from the current cell to the optimal cell if it is determined that the current cell is not the optimal cell, and / or causing the mobile device not to switch from the current cell to another cell if it is determined that the current cell is the optimal cell.

[0037] A non-transitory computer-readable storage medium stores at least a second software code portion, which, when executed or processed by a computer, is configured to perform executable operations for receiving switching instructions.

[0038] The operable operations include: receiving a handover instruction that identifies the mobile device; performing a handover of the mobile device to the best cell specified in the handover instruction; and / or not performing a handover of the mobile device in response to an event reported to the base station if the handover instruction indicates that the mobile device should not be handed over to another cell, the event indicating that another cell has become better than the mobile device's current cell.

[0039] A non-transitory computer-readable storage medium stores at least a third software code portion, which, when executed or processed by a computer, is configured to perform executable operations for reporting events to a base station currently serving a mobile device.

[0040] The executable operations include: reporting an event to a base station currently serving the mobile device, the event indicating that another cell has become better than the mobile device's current cell in terms of communication performance; and receiving a response from the base station to the reported event; and reporting any new event indicating that another cell has become better than the mobile device's current cell in terms of communication performance within a predetermined amount of time, or delaying the reporting, or adjusting one or more thresholds used to determine whether another cell has become better than the mobile device's current cell in terms of communication performance.

[0041] As those skilled in the art will appreciate, aspects of the invention can be implemented as apparatus, methods, or computer program products. Therefore, aspects of the invention can take the form of entirely hardware embodiments, entirely software embodiments (including firmware, resident software, microcode, etc.), or embodiments combining software and hardware aspects (all collectively referred to herein as "circuit," "module," or "system"). The functionality described in this disclosure can be implemented as algorithms executed by a computer's processor / microprocessor. Furthermore, aspects of the invention can take the form of computer program products implemented on one or more computer-readable media having computer-readable program code implemented thereon (e.g., stored thereon).

[0042] Any combination of one or more computer-readable media may be used. A computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium may be, for example, but not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or apparatuses, or any suitable combination of the foregoing. More specific examples of computer-readable storage media may include, but are not limited to, electrical connections having one or more wires, portable computer disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the foregoing. In the context of this invention, a computer-readable storage medium may be any tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or apparatus.

[0043] Computer-readable signal media may include propagated data signals having computer-readable program code implemented therein (e.g., in baseband or as part of a carrier wave). Such propagated signals may take any of a variety of forms, including but not limited to electromagnetic, optical, or any suitable combination thereof. Computer-readable signal media may be any computer-readable medium that is not a computer-readable storage medium and may transmit, propagate, or transfer a program for use by or in conjunction with an instruction execution system, device, or apparatus.

[0044] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, fiber optic, cable, RF, or any suitable combination thereof. Computer program code for performing aspects of the invention may be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java™, Smalltalk, C++, etc., and traditional procedural programming languages ​​such as the “C” programming language or similar programming languages. The program code may be executed entirely on the user's computer, partially on the user's computer, as a stand-alone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or server. In the latter scenario, a remote computer may be connected to the user's computer via any type of network, including a local area network (LAN) or a wide area network (WAN), or (e.g., via the Internet using an Internet service provider) to an external computer.

[0045] Aspects of the invention are described below with reference to flowchart illustrations and / or block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the invention. It will be understood that each block of the flowchart illustrations and / or block diagrams, as well as combinations of blocks in the flowchart illustrations and / or block diagrams, can be implemented by computer program instructions. These computer program instructions can be provided to a processor (particularly a microprocessor or central processing unit (CPU)) of a general-purpose computer or a special-purpose computer, or other programmable data processing apparatus, to produce a machine such that the instructions, executable via the computer's processor, other programmable data processing apparatus, or other means, create components for implementing the functions / actions specified in one or more blocks of the flowchart illustrations and / or block diagrams.

[0046] These computer program instructions may also be stored in a computer-readable medium that can direct a computer, other programmable data processing device or other apparatus to operate in a particular manner, such that the instructions stored in the computer-readable medium produce an article of writing including the instructions, which perform the functions / actions specified in one or more boxes of a flowchart and / or block diagram.

[0047] Computer program instructions can also be loaded onto a computer, other programmable data processing equipment or other apparatus, such that a series of operational steps are executed on the computer, other programmable equipment or other apparatus, thereby producing a computer-implemented process, such that the instructions executed on the computer or other programmable equipment provide a process for implementing the function / action specified in one or more boxes of a flowchart and / or block diagram.

[0048] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of the present invention. In this regard, each block in the flowchart or block diagram may represent a module, segment, or code portion, which includes one or more executable instructions for implementing one or more specified logical functions.

[0049] It should also be noted that in some alternative implementations, the functions annotated in the boxes may occur in a different order than those annotated in the figures. For example, two boxes shown consecutively may actually be executed substantially simultaneously, or sometimes in reverse order, depending on the functionality involved. It will also be noted that each box in the block diagram and / or flowchart description, as well as combinations of boxes in the block diagram and / or flowchart description, may be implemented by a system based on dedicated hardware or a combination of dedicated hardware and computer instructions that performs the specified functions or actions. Attached Figure Description

[0050] Referring to the accompanying drawings, these and other aspects of the invention will be clear and further illustrated by example, wherein: Figure 1 This is a flowchart of a first embodiment of a method for determining the optimal cell; Figure 2 This is a flowchart of a second embodiment of the method for determining the optimal cell; Figure 3 This is a flowchart of a third embodiment of the method for determining the optimal cell; Figure 4 Explanation Figure 2 and Figure 3 Methods; Figure 5 This is a flowchart of the fourth embodiment of the method for determining the optimal cell; Figure 6 Explanation Figure 5 Methods; Figure 7 This is a flowchart of a fifth embodiment of the method for determining the optimal cell and an embodiment of the method for receiving a handover command; Figure 8 This is a flowchart of the sixth embodiment of the method for determining the optimal cell; Figure 9 This is a flowchart of the seventh embodiment of the method for determining the optimal cell; Figure 10 This is a block diagram of an embodiment of the system; and Figure 11 This is a block diagram of an exemplary data processing system for performing the methods of the present invention.

[0051] The same reference numerals are used to denote the corresponding elements in the accompanying drawings. Detailed Implementation

[0052] In a JCAS scenario, deployed cellular base stations, the current UE, potential additional nodes, and (radio / processing) resources can be utilized to handle both communication and sensing tasks. In the simplest scenario, different sets of nodes and resources will participate in handling different tasks, such as those handled by the base station (BS). A and UE A The connection between them uses time-frequency resources (TF). A To handle a given communication task, while, for example, it will be handled by the transmission base station BS. B、C、…、F Receiver base station (BS) G、H、…、L and receiving UEUE B、C、…、H Use time-frequency resources TF B To perform a given sensing task.

[0053] However, in more complex and potentially more efficient scenarios, a given node and / or resources can be shared by one or more communication and sensing tasks, for example, in scenarios where a BS is also used. A In time-frequency resources TF A The services generated above are directed towards the UE. A The transmission of a given communication call, potentially together with other (or communication or dedicated sensing) signals, is used to perform a sensing task by utilizing the received reflections of the transmission.

[0054] In such scenarios, the usefulness of a transmission associated with a given communication task in aiding the sensing task depends, for example, on the directionality of the transmission, which is determined by the serving cell and the applied transmission beam, which are traditionally optimized purely from the perspective of the communication call. Therefore, whether the resulting transmission beam is useful for the current sensing task is merely a result of this communication session-oriented optimization.

[0055] This is seen as an opportunity to make the selection of serving cells, the transmission beams used, and the resources utilized more generally oriented towards JCAS, rather than purely towards communication sessions.

[0056] exist Figure 1 This paper illustrates a first embodiment of a method for determining the optimal cell for serving a mobile device from a plurality of candidate cells. The plurality of candidate cells includes the current cell serving the mobile device. Step 101 includes collecting measurements of the plurality of candidate cells. For example, the measurements may include a received signal strength indicator and / or cell load. Optional step 102 includes obtaining communication requirements.

[0057] Step 103 includes estimating communication performance for each of the multiple candidate cells based on the measurements collected in step 101 and optionally based on the communication requirements obtained in step 102. When estimating communication performance, only the communication performance experienced by the mobile device in question may be estimated, or the communication performance experienced by other devices may also be estimated. This allows the performance impact of potential handovers on other UE sessions to be considered.

[0058] Optional step 105 includes obtaining sensing requirements. Sensing requirements may specify, for example, one or more of the following: one or more target areas, one or more target orientations, one or more target object types, one or more target objects (e.g., one or more object identifiers), target object velocity, target object size, and sensing performance requirements. For example, sensing performance requirements may specify requirements for sensing accuracy, sensing urgency, and / or sensing reliability. For example, sensing accuracy requirements may include target distance resolution. For example, sensing reliability requirements may include a minimum probability of detection and limitations on the false alarm rate.

[0059] Sensing requirements may involve, for example, monitoring or tracking modes: • In monitoring mode, the purpose of sensing is to detect the presence of a target object, typically including one or more of the object's attributes, such as its location. Possible sensing requirements include detection range, detection accuracy, and detection speed (time required), where each of these requirements can potentially be imposed on any target attribute of the object. • In tracking mode, the sensing objective is to follow the trajectory of the sensed target object, which typically requires estimating the object's velocity, its changes, and the direction of its movement. Possible sensing requirements include maximum detectable velocity, granularity of velocity detection, and direction of movement, where each of these requirements can potentially be imposed on any target property of the object or the object's trajectory.

[0060] Both monitoring and tracking modes can be enhanced by further determining factors such as the shape and orientation of the target object being detected / tracked. The possible sensing requirements here are orientation accuracy and shape accuracy.

[0061] Step 107 includes, for example, estimating the sensing performance for each of a plurality of candidate cells based on the sensing requirements obtained in step 105. When estimating sensing performance, this may address one or more sensing tasks that may utilize (or be subject to) current and / or candidate new beams transmitted to the mobile device in question. For example, assuming a particular candidate cell serves the mobile device, the sensing performance for that particular candidate cell can be estimated by estimating the overall sensing performance of one or more sensing tasks. Alternatively, the sensing performance may be estimated based on measurements collected in step 101.

[0062] Steps 101 and 103 and step 107 can be performed in parallel or sequentially (e.g., in sequence 101, 103, 107 or in sequence 107, 101, 103) (fully or partially).

[0063] Step 109 includes identifying the optimal cell for serving the mobile device from among the multiple candidate cells based on the communication performance estimated for the multiple candidate cells in step 103 and the sensing performance estimated for the multiple candidate cells in step 107. In step 109, all relevant advantages and disadvantages related to the QoS (Quality of Service), control signaling overhead, and / or resource utilization efficiency of both the communication and sensing tasks may be considered.

[0064] Step 111 includes: if it is determined in step 109 that the current cell is not the optimal cell, causing the mobile device to hand over from the current cell to the optimal cell, and / or if it is determined in step 109 that the current cell is the optimal cell, causing the mobile device not to hand over from the current cell to another cell. Additionally, it can be... Figure 2-3 One or more steps from one or more embodiments of embodiments 5 and 7-9 are added to Figure 1 In the embodiments described above.

[0065] remove Figure 1 In addition to the method described above, another method can be executed in parallel, which continuously or periodically checks whether the performance requirements of the communication and sensing tasks are met, and triggers an action when they are not. Such actions may include, for example, reselecting which nodes (BS, UE) should participate in performing a given sensing task and which payloads or dedicated sensing signals should be used.

[0066] exist Figure 2 This paper illustrates a second embodiment of a method for determining the optimal cell for serving a mobile device from a plurality of candidate cells. The plurality of candidate cells includes the current cell serving the mobile device. This can be performed for each of the plurality of mobile devices. Figure 2 The method.

[0067] Step 121 includes determining whether the service beam used by the base station to serve the mobile device has been adapted at a given time instance. This beam adaptation can be based on, for example, CSI (Channel State Information) feedback periodically provided by the mobile device or base station measurements based on SRS (Sound Reference Signal) periodically transmitted by the mobile device. Beam adaptation can be performed in a conventional, purely communication-oriented manner, such as when the mobile device is moving, but it can also be performed in a "JCAS" manner, in which case beam adaptation (directivity, beamwidth, transmit power) can be completed while considering the performance requirements of both communication and sensing tasks. Figure 2 The steps for adapting the service beam are not shown in the diagram.

[0068] If it is determined in step 121 that the service beam used by the base station to serve the mobile device has been adapted, then step 107 is performed. Step 107 includes, for example, estimating the sensing performance for each of the plurality of candidate cells based on the obtained sensing requirements.

[0069] Next, step 101 includes collecting measurements of a plurality of candidate cells. Measurements may include a received signal strength indicator and / or cell load. Step 103 includes estimating the communication performance of each of the plurality of candidate cells based on the measurements collected in step 101.

[0070] Step 109 includes identifying the best cell for serving the mobile device from among the multiple candidate cells based on the communication performance estimated for the multiple candidate cells in step 103 and the sensing performance estimated for the multiple candidate cells in step 107.

[0071] Optionally, step 109 includes two sub-steps, a and b. In sub-step a, based on the estimated combined communication and sensing performance for these cells, a preliminary optimal cell for serving the mobile device is identified from all candidate cells other than the current cell. Sub-step b includes determining whether the estimated combined communication and sensing performance for the preliminary optimal cell identified in step a exceeds the estimated combined communication and sensing performance for the current cell, thereby identifying the optimal cell from all candidate cells.

[0072] Step 127 includes determining whether the best cell identified in step 109 is the current cell. If so, step 121 is repeated, and the method is as follows: Figure 2 The process continues as shown. If it is determined in step 127 that the current cell is not the optimal cell, then step 111 is executed. If step 109 includes the aforementioned sub-steps a and b, then step 127 may include: if it is determined in step b that the combined communication and sensing performance estimated for the preliminary optimal cell identified in step a does not exceed the combined communication and sensing performance estimated for the current cell, then the optimal cell is determined to be the current cell. In an alternative embodiment, steps 109 and 127 are combined into a single step.

[0073] exist Figure 2 In this embodiment, step 111 is implemented by step 129. Step 129 includes causing the mobile device to hand over from the current cell to the optimal cell. In this specification, this is also referred to as 'JCAS active handover'. 'JCAS active handover' intentionally alters the connection between the mobile device and the cell, thereby changing the sensing topology (the set of nodes participating in the sensing task). Step 121 is repeated after step 129, and then the method proceeds as follows: Figure 2 Continue as shown. Alternatively, it can be... Figure 3 and 7One or more steps from one or more embodiments of -9 are added to Figure 2 Examples of implementations.

[0074] exist Figure 3 The third embodiment of a method for determining the best cell for serving a mobile device from multiple candidate cells is shown. Figure 3 The embodiment is Figure 2 An extension of the embodiments. In Figure 3 In the embodiments, in Figure 2 Steps 123 and 125 are executed between steps 107 and 101.

[0075] Step 123 includes determining the contribution C of the (overall) sensing performance of the usage pair of the adapted service beam (e.g., implemented by all node pairs for a certain sensing task). The contribution C may be determined based on, for example, sensing requirements obtained regarding the sensing task. Step 125 includes determining whether the contribution C determined in step 123 exceeds a threshold T. For example, the contribution may be a percentage. Optionally, sensing performance requirements are considered in steps 123 and / or 125. If it is determined in step 125 that the contribution C does not exceed the threshold T, step 101 is performed, and then the method proceeds as follows. Figure 3 The shown and about Figure 2 Continue as described. For example, it could be that the mobile device has already moved in the direction that requires the beam to no longer be pointed at the target sensing area.

[0076] If it is determined in step 125 that the contribution C exceeds the threshold T, then step 121 is repeated, and the method proceeds as follows: Figure 3 Continue as shown. Alternatively, it can be... Figure 7-9 One or more steps of one or more embodiments are added to the embodiments. Figure 3 Examples of implementations.

[0077] The benefit of additional steps 123 and 125 is that steps 101, 103, and 109 are not performed if not needed. Steps 123 and 125 can be performed relatively quickly and purely on the network side, and steps 123 and 125 do not require consuming any potentially scarce transmission or processing / energy resources of the mobile device. Since identifying the optimal cell does require consuming potentially scarce processing / energy resources of the mobile device and involves a measurement / reporting process that also requires more time and transmission resource usage, it is beneficial to do so only if it is determined that the contribution has not exceeded a threshold.

[0078] With the help of Figure 4 To explain Figure 2 and Figure 3 'JCAS active handover'. Figure 4In the example, base station 11 uses service beam 51 to serve UE 31 at the first moment. This service beam 51 can also be used to sense one or more objects in the target sensing area 9. The sensing range of service beam 51 is indicated by a dashed ellipse. As a supplement or alternative to using the service beam, one or more beams in the CSI-RS control beam can be used to assist the sensing task. UE 31 moves in the direction of the arrow and remains within cell 41, meaning that UE 31 has not yet entered the optimal service area of ​​base station 12 to the extent indicated by the handover hysteresis and / or trigger time parameters, therefore UE 31 will traditionally (yet) not be handed over to base station 12. As UE 31 moves in the indicated direction, its service beam follows this movement and becomes increasingly unsuitable for use in the sensing task because its transmission direction becomes increasingly mismatched with the location of the target sensing area 9, resulting in increasingly weaker signal reflections from potential objects in the target sensing area 9.

[0079] In a traditional scenario, UE 31 will continue to be served by base station 11 until it crosses the boundary of cell 41, at which point it will be switched to base station 12 for service. However, utilizing... Figure 2 Alternatively, in method 3, a 'JCAS active handover' has been performed when UE 31 arrives at the new location specified in cell 41 at the second time. When using the adapted service beam 52 generated by the original serving base station 11, from the perspective of joint communication and sensing, cell 42 served by base station 12 is identified in step 109 as the optimal cell for serving UE 31. The sensing range of the adapted service beam 52 is indicated by a dashed ellipse. System 1 determines that it is best to actively / prematurely hand over UE 31 to base station 12, taking into account that this results in service beam 53 being established to serve the UE that is directly pointing towards the target sensing area 9. The sensing range of service beam 53 is indicated by a dashed ellipse.

[0080] exist Figure 5 This paper illustrates a fourth embodiment of a method for determining the optimal cell for serving a mobile device from a plurality of candidate cells. The plurality of candidate cells includes the current cell serving the mobile device. The plurality of candidate cells may include only the current cell and other cells. This process can be performed for each of the plurality of mobile devices. Figure 5 The method.

[0081] Step 141 includes determining whether the mobile device has reported (to the base station currently serving the mobile device) an event indicating that another cell has become better than the current cell in terms of communication performance. For example, the mobile device may report that its measurement indicates that the RSRP of the SSB in the neighboring cell is (sufficiently) greater than the RSRP of the strongest SSB in the mobile device's current serving cell.

[0082] If the base station receiving the event report does not perform... Figure 5 The method allows this base station to execute... Figure 5 The method involves receiving system-reported events. It may depend on the timing and information reported by the mobile device and / or the technology and operator-configured handover parameters by which the base station determines whether to communicate a handover request to another base station.

[0083] If it is determined in step 141 that the mobile device has reported an event indicating that another cell has become better than the current cell in terms of communication performance, then step 107 is performed. Step 107 includes, for example, estimating the sensing performance for each of the plurality of candidate cells based on the obtained sensing requirements.

[0084] Next, step 101 includes collecting measurements of a plurality of candidate cells. Step 103 includes estimating communication performance for each of the plurality of candidate cells based on the measurements collected in step 101.

[0085] Step 109 includes identifying the optimal cell for serving the mobile device from the multiple candidate cells based on the communication performance estimated for the multiple candidate cells in step 103 and the sensing performance estimated for the multiple candidate cells in step 107. If the multiple candidate cells only include the current cell and other cells, step 109 may simply include comparing the combined communication and sensing performance of the two cells.

[0086] Step 143 includes determining whether the best cell identified in step 109 is the current cell. If not, step 141 is repeated, and the method is as follows: Figure 5 Continue as shown. Repeating step 141 will allow (i.e., not prevent) the mobile device to be handed over to another cell. If it is determined in step 143 that the current cell is the best cell, then step 111 is performed. In an alternative embodiment, steps 109 and 143 are combined into one step.

[0087] exist Figure 5 In this embodiment, step 111 is implemented by step 145. Step 145 includes preventing the mobile device from handing over from the current cell to another cell. In this specification, this is also referred to as 'JCAS blocking handover'. 'JCAS blocking handover' prevents changes in the connection between the mobile device and the cell, thereby preventing potential changes in the sensing topology that would occur in a conventional handover process.

[0088] Step 145 may include instructing the base station not to perform a handover in response to an event being reported to the base station, for example, if the base station does not perform a handover. Figure 5 That is the method. Alternatively, you can... Figure 7-9 One or more steps of one or more embodiments are added to the embodiments. Figure 5 Examples of implementations.

[0089] exist Figure 5 In one embodiment, in response to a conventional trigger (i.e., a reported event indicating that another cell has become better than the current cell in terms of communication performance), 'JCAS prevent handover' is performed. If such an event would normally trigger a handover, then if it is determined that the current cell is the best cell (i.e., it is determined that it is the cell estimated to provide the best combination of sensing and communication performance), then such a handover can be prevented.

[0090] With the help of Figure 6 To explain Figure 5 'JCAS prevents switching'. Figure 6 In the example, similar to in Figure 4 In the example, base station 11 serves UE 31 using service beam 51 at the first moment, and this service beam 51 can also be used to sense one or more objects in the target sensing area 9. UE 31 moves in the direction of the arrow. As UE 31 moves away from its serving base station (i.e., base station 11), its connection strength becomes weaker, and at some point, UE 31 begins scanning for candidate surrounding cells to switch to.

[0091] In a traditional scenario, UE 31 would continue to be served by base station 11 until it crosses the boundary of cell 41 (reflected in, for example, a drop in the measured SSB RSRP below a certain threshold), and then be switched to base station 12 for service. However, using... Figure 5 The method, which traditionally involves a natural handover being prevented in step 145, is therefore 'JCAS prevents the handover'. Figure 5 In step 109, cell 41 is identified as the best cell at the new location of UE 31 because, despite its weakened link, base station 11 continues to serve the UE with a traffic beam 52 that is precisely directed toward the target sensing area 9 and is therefore more advantageous for the current sensing task than the traffic beam 53 alternatively provided by base station 12 / cell 42.

[0092] Therefore, System 1 prevents the mobile device from switching from cell 41 to cell 42. Figure 6 In the example, it is possible to sacrifice a certain quality level of the communication task in order to improve the implementation quality of the sensing task (e.g., accuracy, reliability, latency). The sensing range of service beams 51-53 is indicated by the dashed ellipse.

[0093] exist Figure 7 The fifth embodiment of the method for determining the best cell for serving a mobile device from multiple candidate cells is shown. Figure 7 The fifth embodiment is Figure 1 An extension of the first embodiment. Figure 7 An embodiment of a method for receiving a switching command is also shown.

[0094] exist Figure 7 In the embodiment, step 161 has already been implemented. Figure 1 Step 111. Step 111 includes: if it is determined in step 109 that the current cell is not the best cell, causing the mobile device to switch from the current cell to the best cell, and / or if it is determined in step 109 that the current cell is the best cell, causing the mobile device not to switch from the current cell to another cell.

[0095] Step 161 includes transmitting a handover instruction to the base station. The handover instruction identifies the mobile device. The handover instruction may request the base station to hand over the mobile device to the cell specified in the handover instruction, i.e., the best cell identified in step 109, or may simply identify the best cell. Alternatively, the handover instruction may indicate that the mobile device should not be handed over to another cell. Step 163 includes the base station receiving the handover instruction.

[0096] Step 165 includes: performing a handover of the mobile device to the best cell specified in the handover instruction, and / or, if the handover instruction indicates that the mobile device should not be handed over to another cell, not performing a handover of the mobile device in response to an event reported to the base station. This event indicates that the other cell has become better than the mobile device's current cell in terms of communication performance. The mobile device reporting this event to the base station currently serving the mobile device may receive a response from the base station to the reported event, and within a predetermined time, either postpone reporting any new events indicating that the other cell has become better than the mobile device's current cell in terms of communication performance, or adjust one or more thresholds used to determine whether the other cell has become better than the mobile device's current cell in terms of communication performance. Figure 7 The reception of this event is not shown in the document. Alternatively, it can be... Figure 2-3 One or more steps from one or more embodiments of embodiments 5 and 8-9 are added to Figure 7 Examples of implementations.

[0097] exist Figure 8 The sixth embodiment of a method for determining the best cell for serving a mobile device from multiple candidate cells is shown. Figure 8 The embodiment is Figure 1 An extension of the embodiments. In Figure 8 In one embodiment, step 109 is implemented by step 175, and steps 171 and 173 are performed before step 175.

[0098] Step 171 includes obtaining the operator policy with specified weights. Steps 101 and 103, 107 and 171 can be performed in parallel or sequentially (e.g., in the order of 171, 101, 103, 107 or in the order of 107, 101, 103, 171) (fully or partially). Step 173 includes assigning the weights obtained in step 171 to the communication performance estimated in step 103 and / or the sensing performance estimated in step 105.

[0099] Step 175 includes identifying the optimal cell for serving the mobile device from a plurality of candidate cells based on the communication performance estimated (if applicable, weighted using the weights assigned in step 173) for the plurality of candidate cells in step 103 and the sensing performance estimated (if applicable, weighted using the weights assigned in step 173) for the plurality of candidate cells in step 107. Additionally, [the following can be added] Figure 2-3 One or more steps from one or more embodiments of embodiments 5, 7, and 9 are added to Figure 8 Examples of implementations.

[0100] exist Figure 9 The diagram illustrates a seventh embodiment of a method for determining the optimal cell for serving a mobile device from a plurality of candidate cells. Step 181 includes collecting measurements of a plurality of candidate reference beams. Each of the plurality of candidate reference beams is associated with one of the candidate cells in the plurality of candidate cells.

[0101] For example, in the case of 5G, candidate reference beams may include synchronization signal block beams. The measurements collected in step 181 may be SSB RSRP measurements, for example, by: (a) requiring the mobile device to perform a routine scan of (cell, SSB) pairs in the surrounding cells and report those pairs whose RSRP exceeds a given threshold; or (b) instructing the mobile device to measure a specific set of (cell, SSB) pairs that have been pre-selected as potentially useful from both a communication and sensing perspective using, for example, radio network planning tools and mobile device location estimation.

[0102] Step 183 includes estimating communication performance for each of the multiple candidate reference beams based on the measurements collected in step 181. For the current serving cell (which is among the candidate cells), communication performance may also be estimated based on the actual service beam (e.g., the experience performance of the actual service beam) rather than solely on the reference beam.

[0103] Optionally, step 183 may include adjusting the estimated communication performance based on the beam differences between multiple candidate reference beams and their corresponding service beams. Since reporting on non-serving cells is typically based on SSB measurements, and actual payload transmission usually uses a narrower service beam, the additional beamforming gain of the narrower service beam can be considered in this way compared to a wider SSB (reference) beam. Furthermore, the estimation may consider beam adjustments relative to the reported SSB beam consistent with beam adaptation performed in a "JCAS manner".

[0104] Step 185 includes, for example, estimating the sensing performance for each of the multiple candidate reference beams based on the obtained sensing requirements. For example, assuming that a mobile device is served by a particular candidate reference beam (preferably with a suitably adjusted radiation pattern and higher main lobe gain because the service beam is typically narrower and has higher beamforming gain compared to the reference beam), the sensing performance for this particular candidate reference beam can be determined by determining the overall sensing performance of one or more sensing tasks.

[0105] In step 185, sensing performance can be determined by determining a value representing a sensing performance estimate for each sensing task, and, in the case of multiple sensing tasks, by determining additional values ​​representing a sensing performance estimate for all sensing tasks based on multiple values. For example, these values ​​could be SNR values, detection probability values ​​(e.g., converted from SNR values), or values ​​that integrate the detection probability under some conditions related to false alarm rate, sensing accuracy, and / or sensing time.

[0106] Each sensing task involves one or more pairs of nodes. If a single transmitter transmits to multiple receivers, the sensing task may include a pair of nodes for each corresponding receiver of the multiple receivers, with each pair including the transmitter and the corresponding receiver. If multiple transmitters transmit to multiple receivers, the sensing task may include a pair of nodes for each combination of a single transmitter among the multiple transmitters and a single receiver among the multiple receivers.

[0107] exist Figure 9 In this embodiment, at least one of these node pairs is a node pair that includes a mobile device as a receiver. This node pair includes a base station that acts as a transmitter to provide coverage to the candidate reference cell. If two candidate cells exist (e.g., BS...), A and BS B ) and five candidate reference beams (e.g., BS) A -SSB1、BS A -SSB2、BS A -SSB3、BS B -SSB1、BS BIf -SSB2), then five values ​​are determined (if there is one sensing task) or five other values ​​(if there are multiple sensing tasks), and a reference beam with the best (other) value is selected.

[0108] To determine the detection probability, the BS / cell and UE locations can be considered, as the BS / cell and the UE location relative to the potential location of the sensed object will affect propagation loss, SNR estimation, and therefore the detection probability. To determine the detection probability, cell-specific azimuth / tilt / antenna orientation / maximum transmit power and the carrier frequency assigned to the cell can be considered, as these parameters affect propagation loss, SNR estimation, and the detection probability. To determine the detection probability, the cell / UE receiver sensitivity / noise figure / other characteristics can be considered, as these parameters affect SNR estimation and therefore the detection probability.

[0109] The detection probability can be calculated by first applying radar equations at the pixel level (a portion of the target sensing region) and then integrating these over the target sensing region. An example of how the detection probability can be calculated is given below. To estimate the detection probability, the target sensing region is divided into sets of non-overlapping pixels, either in two-dimensional or three-dimensional space, depending on its dimensionality.

[0110] The detection probability of each node combination can be estimated for each pixel in the target sensing area first, as shown below: i. Calculate / estimate from N s Distance between all receivers and the target 3D pixel ii. Calculate / estimate from M s Distance between all transmitters and 3D pixels , iii. Calculate / estimate the received signal power for all pairs: in, and and iv. The combined SNR used to consider the total number of receivers and transmitters in a given set further depends on whether the signals are (a) coherent combinations or (b) incoherent combinations.

[0111] ▪ Assuming a fully synchronized system operating coherently, the combined SNR (for a specific pixel and a given set of transmitters and receivers) is given by the following formula. .

[0112] ▪ Alternatively, combining the signals in an incoherent manner will produce a slightly lower total SNR (for a specific pixel and a given set of transmitters and receivers), given by the following formula: .

[0113] in, v. Convert the total SNR into detection probability (using a graph of detection probability versus SNR).

[0114] In the above calculation of the detection probability, it is assumed that signals from all receivers (e.g., IQ samples, plot-level information) are available at the system. Different methods exist for calculating the detection probability, which may be appropriate in some scenarios, such as when there are no signals (IQ samples) from all receivers at the system. For example, the steps mentioned above can be used to calculate the detection probability by assuming that each receiver independently determines its own receiver-specific probability. P detection,j However, in this case, for example, appropriate adjustments need to be made to the equations in steps (iii) and (iv-a), that is, the equations can be adjusted accordingly. Calculated as This strategy assumes that one detection is sufficient. Other strategies are also possible.

[0115] Information such as the specified center wavelength, transmit power of the i-th transmitter, antenna gain, form factor, loss, distance, equivalent system temperature, and (noise) bandwidth at the j-th receiver can be obtained from the node. Typically, the receiver manufacturer specifies the system noise temperature (or equivalent noise figure / factor, which can be converted to noise temperature as Fs = 1 + Ts / 290).

[0116] The (bibase) RCS of a given pair (i, j) can be determined based on sensing requirements. For example, sensing requirements may specify the average / minimum / range of one or more RCS values ​​for a given sensing task. Tables with average RCS values ​​for certain objects (e.g., people and aircraft) exist in the literature.

[0117] Assuming the use of at least one reference beam, the received signal power of each transmitter and receiver pair is calculated / estimated in step iii). Assuming one or more other beams (e.g., service beams) can also be used, the received signal power of each transmitter and receiver pair may be further calculated / estimated in step iii). Antenna gain and / or loss can be determined based on the beam characteristics of this beam / the beams. Even if the transmitter transmits a dedicated sensing signal, antenna gain and loss will typically vary between pixels in the target sensing area.

[0118] Once the pixel-specific detection probabilities have been estimated, the total probability of detection for the entire target sensing area can be determined, for example, by directly averaging the pixel-specific detection probabilities for the same possible pixel occupancy. Alternatively, in cases where, for example, the target object is more likely to appear near the center of the target sensing area, a weighted average can be used, and therefore, it is more important that the detection probability is high in pixels located more centrally.

[0119] Preferably, the total detection probability of the entire target sensing area is estimated for an observation window that can attempt to detect one or more objects multiple times. The detection probability increases with the number of attempts, as each additional attempt provides an additional chance for successful sensing. Using p... n Estimated probability when trying n It can be used as an estimated probability after N attempts. If the receiver receives a first beam with first beam characteristics from the transmitter at the first moment and a second beam with second beam characteristics from the same transmitter at the second moment, the detection probability may be different.

[0120] Instead of determining the total probability of detection for the entire target sensing area, the total SNR for the entire target sensing area can be determined by, for example, a direct averaging of pixel-specific SNR values. This total SNR value can be used as an estimate of sensing performance, rather than the total detection probability.

[0121] In the above calculation description, it is assumed that sensing is performed in monitoring mode. When sensing is performed in tracking mode, additional data is available and can be used. For example, instead of estimating the RCS based on sensing requirements, the RCS can be estimated based on the sensing data. It is also possible to determine the position estimate and / or SNR estimate based on the sensing data, and the target sensing area can be estimated based on a previously determined position estimate and its surrounding confidence interval. Therefore, if detection has occurred and tracking mode is active, sensing information such as position estimate, SNR estimate, and RCS estimate can be used. If monitoring mode is active, the calculation typically relies on specifications and tables.

[0122] When in Figure 3In step 123, when determining the contribution C of the (overall) sensing performance using the adapted service beampair (e.g., for a sensing task implemented by all node pairs), the above calculation can be used to determine this contribution. For example, for a sensing task (e.g., monitoring), step 123 determines the contribution of this pair of nodes to the overall performance metric (e.g., detection probability when in monitoring mode; velocity accuracy of the target in tracking mode). Because the relationship between SNR and, for example, detection probability is not linear, one way to calculate the contribution is to compare the detection probability with and without this pair. The gain in detection probability caused by this pair can then be used as its contribution. If the sensing task involves only one pair of nodes, then the contribution of this pair will be 100%. When performing step 109, the individual contributions and the total SNR value may have already been calculated and stored in the manner described above. Alternatively, the contribution C may have already been calculated and stored in step 109, and can then be simply retrieved in step 123.

[0123] Optionally, step 185 may include adjusting the estimated sensing performance based on the beam differences between multiple candidate reference beams and the corresponding estimated service beams. Furthermore, the estimation may take into account beam adjustments relative to the reported SSB beams consistent with beam adaptation performed in a “JCAS manner”.

[0124] Step 187 includes identifying the optimal reference beam from multiple candidate reference beams based on the (optionally adjusted) communication performance estimated for multiple candidate reference beams in step 183 and the sensing performance estimated for multiple candidate reference beams in step 185. For example, step 187 may include selecting the candidate (cell, SSB) pair with the highest combined communication and sensing performance. Figure 9 Methods and Figure 8 The combination of methods can then identify the optimal reference beam in step 187 based on the communication and sensing performance of a weighted combination of each pair in the measurement / report (cell, SSB) pair, where the degree of weighting or prioritization is specified by the operator's policy.

[0125] Step 189 includes identifying the optimal cell for serving the mobile device from a plurality of candidate cells by determining the cell associated with the optimal reference beam identified in step 187. Step 111 includes: if it is determined in step 189 that the current cell is not the optimal cell, causing the mobile device to hand over from the current cell to the optimal cell, and / or if it is determined in step 189 that the current cell is the optimal cell, causing the mobile device not to hand over from the current cell to another cell.

[0126] Optionally, step 191 is performed after step 111. Step 191 includes instructing the mobile device to identify the optimal reference beam or causing the base station to instruct the mobile device to identify the optimal reference beam. For example, the service beam corresponding to the selected SSB beam can be assigned to the UE by specifying only the selected SSB beam and its associated RACH resources in the RRCReconfiguration message. This can be used to ensure that the service beam corresponding to the optimal reference beam is actually assigned to the UE if the service beam corresponding to the reference beam identified as the optimal reference beam will not or may not be automatically assigned to the UE when the cell of this beam is identified as the optimal cell. Alternatively, the service beam corresponding to the optimal reference beam can be... Figure 2-3 One or more steps from one or more embodiments of embodiments 5 and 7-8 are added to Figure 9 Examples of implementations.

[0127] Figure 10 This is a block diagram of an embodiment of a system (system 1) for determining the optimal cell for serving a mobile device and an embodiment of base stations (base stations 11 and 12) for receiving handover instructions. Figure 10 A single UE 31 is further illustrated. In this embodiment, for example, system 1 is separate from the base station and the UE, and may be located in the radio access network. For example, base stations 11 and 12 may include multiple distributed units sharing a common centralized unit in a centralized RAN (C-RAN) architecture.

[0128] System 1 includes a receiver 3, a transmitter 4, a processor 5, and a memory 7. The processor 5 is configured to: collect measurements of a plurality of candidate cells, estimate communication performance for each candidate cell based on the measurements, and estimate sensing performance for each candidate cell, for example, for sensing a target object 9. The plurality of candidate cells includes the current cell serving the mobile device.

[0129] The processor 5 is further configured to: identify the best cell for serving the mobile device from among the multiple candidate cells based on the communication performance estimated for the multiple candidate cells and the sensing performance estimated for the multiple candidate cells, and cause the mobile device to switch from the current cell to the best cell if it is determined that the current cell is not the best cell, and / or cause the mobile device not to switch from the current cell to another cell if it is determined that the current cell is the best cell.

[0130] exist Figure 10In this embodiment, the processor 5 is further configured to transmit a handover instruction to the base station 11 or 12. The handover instruction identifies the mobile device. The handover instruction may request the base station to hand over the mobile device to the cell specified in the handover instruction, i.e., the best cell identified in step 109, or may simply identify the best cell. Alternatively, the handover instruction may indicate that the mobile device should not be handed over to another cell.

[0131] Base stations 11 and 12 each include a receiver 23, a transmitter 24, a processor 25, and a memory 27. Figure 10 In one embodiment, the processor 25 is configured to: receive a handover instruction identifying a mobile device; and perform a handover of the mobile device to the best cell specified in the handover instruction, and / or, if the handover instruction indicates that the mobile device should not be handed over to another cell, not perform a handover of the mobile device in response to an event reported to the base station indicating that the other cell has become better than the mobile device’s current cell in terms of communication performance.

[0132] When base station 11 serves UE 31, system 1 transmits a handover command to base station 11. When base station 12 serves UE 31, system 1 transmits a handover command to base station 12.

[0133] exist Figure 10 In the embodiment shown, mobile device 31 includes receiver 43, transmitter 44, processor 45, and memory 47. Processor 45 is configured to: (via transmitter 44) report to a base station currently serving mobile device 31 an event indicating that another cell has become better than the current cell of mobile device 31 in terms of communication performance; and (via receiver 43) receive a response to the reported event from the base station; and, within a predetermined time, either postpone reporting any new event indicating that another cell has become better than the current cell of mobile device 31 in terms of communication performance, or adjust one or more thresholds used to determine whether another cell has become better than the current cell of mobile device 31 in terms of communication performance.

[0134] When base station 11 serves UE 31, UE 31 reports events to base station 11. When base station 12 serves UE 31, UE 31 reports events to base station 12.

[0135] exist Figure 10In the embodiment shown, system 1 includes a processor. In alternative embodiments, system 1 includes multiple processors. For example, processor 5 may be a general-purpose processor (e.g., an Intel or AMD processor) or a dedicated processor. For example, processor 5 may include multiple cores. For example, processor 5 may run a Unix-based or Windows operating system. For example, memory 7 may include solid-state storage (e.g., one or more solid-state drives (SSDs) made of flash memory) or one or more hard disks.

[0136] Receiver 3 and transmitter 4 can communicate with base stations 11 and 12 using one or more wired or wireless communication technologies. For example, receiver 3 and transmitter 4 can communicate with other systems in the radio access network or core network using one or more communication technologies (wired or wireless). Receiver 3 and transmitter 4 can be combined in a transceiver. System 1 may include other components typical of components in a mobile communication network, such as a power supply.

[0137] exist Figure 10 In the embodiments shown, base stations 11 and 12 include a processor. In alternative embodiments, one or more of base stations 11 and 12 may include multiple processors. For example, the processors of base stations 11 and 12 may be general-purpose processors (e.g., Intel or AMD processors) or dedicated processors. For example, the processor may include multiple cores. For example, the processor may run a Unix-based or Windows operating system. For example, memory 27 may include solid-state storage (e.g., one or more solid-state drives (SSDs) made of flash memory) or one or more hard disks.

[0138] Receiver 23 and transmitter 24 can communicate with the UE (e.g., UE 31) using one or more wireless communication technologies (such as Wi-Fi, LTE, and / or 5G New Radio). For example, receiver 23 and transmitter 24 can communicate with other systems in the radio access network or core network using one or more communication technologies (wired or wireless). Receiver 23 and transmitter 24 can be combined in a transceiver. The base station may include other components typical of components in a mobile communication network, such as a power supply. Figure 10 In the embodiments shown, for example, each base station in a base station may include a single unit or a central unit and one or more distributed units.

[0139] exist Figure 10 In the embodiment shown, mobile device 31 includes a processor 45. In alternative embodiments, mobile device 31 includes multiple processors. Processor 45 may be a general-purpose processor (e.g., an ARM or Qualcomm processor) or a dedicated processor. For example, processor 45 may run Google Android or Apple iOS as an operating system.

[0140] For example, the receiver 43 and transmitter 44 of mobile device 31 may communicate with a base station using one or more wireless communication technologies, such as Wi-Fi, LTE, and / or 5G NR. The receiver 43 and transmitter 44 may be combined in a transceiver. UE 31 may include other components typical of user equipment, such as a battery and / or power connector.

[0141] The UE may also be referred to by those skilled in the art as a mobile station (MS), user station, mobile unit, subscriber unit, radio unit, radio terminal, radio device, wireless communication device, remote device, mobile subscriber station, access terminal (AT), mobile terminal, remote terminal, mobile phone, terminal, user agent, mobile client, client, or any other suitable term.

[0142] Figure 11 The description can be executed as per the reference. Figure 1-3 Block diagram of an exemplary data processing system for the methods described in 5 and 7-9.

[0143] like Figure 11 As shown, the data processing system 300 may include at least one processor 302 coupled to a memory element 304 via a system bus 306. Thus, the data processing system can store program code within the memory element 304. Furthermore, the processor 302 can execute program code accessed from the memory element 304 via the system bus 306. In one aspect, the data processing system may be implemented as a computer suitable for storing and / or executing program code. However, it should be understood that the data processing system 300 may be implemented in the form of any system including a processor and memory capable of performing the functions described herein.

[0144] Memory element 304 may include one or more physical memory devices, such as, for example, local memory 308 and one or more mass storage devices 310. Local memory may refer to random access memory or one or more other non-persistent memory devices that are typically used during the actual execution of the program code. Mass storage devices may be implemented as hard disk drives or other persistent data storage devices. Processing system 300 may also include one or more cache memories (not shown) that provide temporary storage for at least some program code to reduce the number of times program code must be retrieved from mass storage device 310 during execution.

[0145] The input / output (I / O) devices, depicted as input device 312 and output device 314, may optionally be coupled to the data processing system. Examples of input devices may include, but are not limited to, a keyboard, a pointing device such as a mouse, etc. Examples of output devices may include, but are not limited to, a monitor or display, a speaker, etc. The input and / or output devices may be coupled to the data processing system either directly or through an intermediate I / O controller.

[0146] In embodiments, the input and output devices may be implemented as a combined input / output device (in... Figure 11 (Illustrated by the dashed lines surrounding input device 312 and output device 314). An example of such a combined device is a touch-sensitive display, sometimes referred to as a "touchscreen display" or simply a "touchscreen". In such embodiments, input to the device can be provided by moving a physical object (such as, for example, a user's stylus or finger) on or near the touchscreen display.

[0147] Network adapter 316 can also be coupled to the data processing system to enable it to couple to other systems, computer systems, remote network devices, and / or remote storage devices via an intermediate private or public network. The network adapter may include a data receiver for receiving data transmitted to the data processing system 300 from the systems, devices, and / or networks, and a data transmitter for transmitting data from the data processing system 300 to the systems, devices, and / or networks. Modems, cable modems, and Ethernet cards are examples of different types of network adapters that can be used with the data processing system 300.

[0148] like Figure 11 As depicted, memory element 304 can store application 318. In various embodiments, application 318 can be stored in local memory 308, one or more mass storage devices 310, or separately from local memory and mass storage devices. It should be understood that data processing system 300 can further execute an operating system that can facilitate the execution of application 318. Figure 11 (Not shown in the document). The application 318, implemented in the form of executable program code, can be executed by the data processing system 300 (e.g., by the processor 302). In response to executing the application, the data processing system 300 can be configured to perform one or more operational or method steps described herein.

[0149] Various embodiments of the present invention can be implemented as a program product for use with a computer system, wherein one or more programs of the program product define the functionality of the embodiments (including the methods described herein). In one embodiment, one or more programs may be included on various non-transitory computer-readable storage media, wherein, as used herein, the expression “non-transitory computer-readable storage media” includes all computer-readable media, with the sole exception being transient propagation signals. In another embodiment, one or more programs may be included on various transient computer-readable storage media. Illustrative computer-readable storage media include, but are not limited to: (i) non-writable storage media on which information is permanently stored (e.g., read-only memory devices within a computer, such as CD-ROM discs readable by a CD-ROM drive, ROM chips, or any type of solid-state non-volatile semiconductor memory); and (ii) writable storage media on which variable information is stored (e.g., flash memory, floppy disks or hard disk drives within a floppy disk drive, or any type of solid-state random access semiconductor memory). The computer program may run on the processor 302 described herein.

[0150] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used herein, the singular forms “a,” “an,” and “described” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprising” and / or “including” as used in this specification refer to the presence of the stated features, integers, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0151] All components or steps plus functional elements in the following claims are intended to include any structure, material, action, and equivalent for performing a function in combination with other claimed elements, such as those specifically claimed. Descriptions of embodiments of the invention have been presented for illustrative purposes, but are not intended to be exhaustive or limited to implementations of the disclosed forms. Many modifications and variations will be apparent to those skilled in the art without departing from the scope of the invention. Embodiments were chosen and described in order to best explain the principles of the invention and some practical applications, and to enable others skilled in the art to understand that various embodiments of the invention with various modifications are suitable for the particular intended use.

Claims

1. A system (1) for determining a best cell for serving a mobile device (31) from a plurality of candidate cells (41, 42), the plurality of candidate cells (41, 42) including a current cell (41) serving the mobile device (31), the system (1) comprising at least one processor (5) configured to: - collect measurements of the plurality of candidate cells (41, 42), - estimate a communication performance for each of the plurality of candidate cells (41, 42) based on the measurements, - estimate a sensing performance for each of the plurality of candidate cells (41, 42), - identify a best cell for serving the mobile device (31) from the plurality of candidate cells (41, 42) based on the communication performance estimated for the plurality of candidate cells (41, 42) and the sensing performance estimated for the plurality of candidate cells (41, 42), and - cause the mobile device (31) to handover from the current cell (41) to the best cell if it is determined that the current cell (41) is not the best cell, and / or cause the mobile device (31) not to handover from the current cell (41) to another cell if it is determined that the current cell (41) is the best cell.

2. The system (1) as claimed in claim 1, wherein, The at least one processor (5) is configured to: - collect the measurements of the plurality of candidate cells (41, 42) by collecting measurements of a plurality of candidate reference beams, each of the plurality of candidate reference beams being associated with one of the plurality of candidate cells (41, 42), - estimate the communication performance for each of the plurality of candidate cells (41, 42) by estimating a communication performance for each of the plurality of candidate reference beams based on the measurements, - estimate the sensing performance for each of the plurality of candidate cells (41, 42) by estimating a sensing performance for each of the plurality of candidate reference beams, - identify a best reference beam from the plurality of candidate reference beams based on the communication performance estimated for the plurality of candidate reference beams and the sensing performance estimated for the plurality of candidate reference beams, and - identify the best cell for serving the mobile device (31) by determining a cell associated with the best reference beam.

3. The system (1) as claimed in claim 2, wherein, The at least one processor (5) is configured to: - adjust the communication performance estimated for the plurality of candidate reference beams based on a beam difference between the plurality of candidate reference beams and corresponding traffic beams, and - identify the best reference beam from the plurality of candidate reference beams based on the sensing performance estimated for the plurality of candidate reference beams and the adjusted communication performance.

4. The system (1) according to claim 2 or 3, wherein The at least one processor (5) is configured to instruct the mobile device (31) to identify the best reference beam or to cause a base station (11, 12) to instruct the mobile device (31) to identify the best reference beam.

5. The system (1) as claimed in claim 2, 3 or 4, wherein The candidate reference beams comprise synchronization signal block beams.

6. The system (1) according to any one of the preceding claims, wherein, The at least one processor (5) is configured to: - determine a contribution of a use of a serving beam to a sensing performance, the serving beam being used by a base station (11, 12) in the current cell (41) to serve the mobile device (31), - determine whether the contribution exceeds a threshold, and - upon determining that the contribution does not exceed the threshold, identify the best cell for serving the mobile device (31) based on the communication performance and the sensing performance, and cause the mobile device (31) to hand over from the current cell (41) to the best cell if it is determined that the current cell (41) is not the best cell.

7. The system (1) according to any one of the preceding claims, wherein, The at least one processor (5) is configured to: - upon determining that the mobile device (31) has reported an event indicating that a further cell has become better than the current cell (41) in terms of communication performance, identify the best cell for serving the mobile device (31), the event being reported to a base station (11, 12) currently serving the mobile device (31), and - cause the mobile device (31) not to hand over from the current cell (41) to a further cell if it is determined that the current cell (41) is the best cell.

8. The system (1) as claimed in claim 7, wherein, The at least one processor (5) is configured to cause the mobile device (31) not to hand over from the current cell (41) to a further cell by instructing the base station (11, 12) not to perform a handover in response to the event being reported to the base station (11, 12).

9. The system (1) as claimed in claim 7 or 8, wherein, The plurality of candidate cells (41, 42) comprises only the current cell (41) and the further cell.

10. The system (1) according to any one of the preceding claims, wherein, The at least one processor (5) is configured to: - obtain an operator policy, the operator policy specifying a weight, - assign the weight to the communication performance and / or to the sensing performance, and - identify the best cell for serving the mobile device (31) based on a weighted communication performance and / or a weighted sensing performance.

11. The system (1) according to any one of the preceding claims, wherein, The measurements comprise a received signal strength indicator and / or a cell load.

12. A base station (11, 12) for receiving a handover instruction, the base station (11, 12) serving a mobile device (31), the base station (11, 12) comprising at least one processor (25), the at least one processor being configured to: - receive a handover instruction, the handover instruction identifying the mobile device (31), and - perform a handover of the mobile device (31) to a best cell specified in the handover instruction, and / or not to perform a handover of the mobile device (31) in response to an event being reported to the base station (11, 12), the event indicating that a further cell has become better than a current cell (41) of the mobile device (31) in terms of communication performance, if the handover instruction indicates that the mobile device (31) shall not be handed over to a further cell.

13. A mobile device (31) for reporting events to a base station (11, 12) currently serving the mobile device (31), the mobile device (31) comprising at least one processor configured to: - report an event to the base station (11, 12) currently serving the mobile device (31), the event indicating that a further cell has become better than a current cell (41) of the mobile device (31) in terms of communication performance, and - receive a response from the base station (11, 12) to the reported event, and - within a predetermined amount of time, either postpone reporting any new event indicating that the further cell has become better than the current cell (41) of the mobile device (31) in terms of communication performance, or adjust one or more thresholds used for determining whether the further cell has become better than the current cell (41) of the mobile device (31) in terms of communication performance.

14. A method of determining a best cell for serving a mobile device from a plurality of candidate cells, the plurality of candidate cells including a current cell serving the mobile device, the method comprising: - collecting (101) measurements of the plurality of candidate cells; - estimating (103) a communication performance for each of the plurality of candidate cells based on the measurements; - estimating (107) a sensing performance for each of the plurality of candidate cells; - identifying (109) a best cell for serving the mobile device from the plurality of candidate cells based on the communication performance estimated for the plurality of candidate cells and the sensing performance estimated for the plurality of candidate cells; and - causing (111) the mobile device to handover from the current cell to the best cell if it is determined that the current cell is not the best cell, and / or causing the mobile device not to handover from the current cell to another cell if it is determined that the current cell is the best cell.

15. A method of receiving a handover instruction, the method comprising: - receiving (163) a handover instruction, the handover instruction identifying a mobile device; and - performing (165) a handover of the mobile device to a best cell specified in the handover instruction, and / or not performing a handover of a mobile device in response to an event being reported to the base station, the event indicating that a further cell has become better than the current cell of the mobile device.

16. A method of reporting an event to a base station currently serving a mobile device, the method comprising: - reporting an event to the base station currently serving the mobile device, the event indicating that a further cell has become better than a current cell of the mobile device in terms of communication performance, and - receiving a response from the base station to the reported event. ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ ​ - within a predetermined amount of time, or postponing reporting any new event indicating that the further cell has become better than the current cell of the mobile device in terms of communication performance, or adjusting one or more thresholds used for determining whether the further cell has become better than the current cell of the mobile device in terms of communication performance.

17. Computer program or suite of computer programs comprising at least one software code portion, or computer program product storing at least one software code portion, the software code portion, when executed on a computer system, being configured for performing the method according to claim 14, 15 or 16.

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