WO2024027889A1

WO2024027889A1 - Methods and apparatus of managing communication resources of a wireless communication network for radar use

Info

Publication number: WO2024027889A1
Application number: PCT/EP2022/071522
Authority: WO
Inventors: Ashkan KALANTARI; Henrik Sjöland; Andres Reial; Fredrik Dahlgren; Magnus Sandgren; Ricardo BLASCO SERRANO; Gang ZOU
Original assignee: Telefonaktiebolaget Lm Ericsson (Publ)
Priority date: 2022-08-01
Filing date: 2022-08-01
Publication date: 2024-02-08

Abstract

Methods and apparatus disclosed herein offer advantageous approaches to allocating communication resources of a wireless communication network for radar usage by respective wireless communication devices, with such approaches including efficient mechanisms for devices to request allocations and the network to grant and manage such allocations. In one aspect, the disclosed methods and apparatus include a modified or repurposed random access (RA) procedure by which given devices may request radar resources without necessarily connecting to the network and without requiring burdensome signaling.

Description

METHODS AND APPARATUS OF MANAGING COMMUNICATION RESOURCES OF A WIRELESS COMMUNICATION NETWORK FOR RADAR USE

TECHNICAL FIELD

Methods and apparatus disclosed herein provide for allocating communication resources of a wireless communication network for radar usage by respective wireless communication devices.

BACKGROUND

A “User Equipment” or UE refers to a wireless communication device that is associated in some sense with an end user who consumes one or more communication services provided by a wireless communication network, such as a cellular network based on Third Generation Partnership Project (3 GPP) specifications. Some types of UEs provide personal communication services and media consumption, such as smartphones or tablets or computers that have cellular or other network modems included therein. Other types of UEs are embedded, such as in sensing or control systems that rely on wireless connections for data and control communications, or in vehicular systems where the UEs provide connectivity for various communication, control, or safety applications.

As signal frequencies used for wireless communications extend upward into the frequency ranges associated with radar operations, new opportunities exist for radar sensing using communication resources associated with wireless communications. As used herein, the term “communication resource” refers, at a minimum, to a particular frequency or frequency range. However, depending upon the type of wireless communication network involved, the term may connote further types of resources that are used to distinguish individual transmissions of control signaling or data within the network. Examples include any one or more of time resources, codes, sequences, spatial directions, or spatial layers. For example, a single subcarrier of an Orthogonal Frequency Division Multiplexing (OFDM) carrier represents different communication resources at different symbol times, or when transmitted in different directional beams or spatial multiplexing layers.

Thus, the term “transmission resource” may be used interchangeably with “communication resource.” Correspondingly, unless otherwise noted, the term “radar resource” herein refers to a communication resource that is allocated, at least temporarily, for radar usage. Such allocations may involve persistent reservations or dynamic allocations, or both, and may be referenced to specific locations or spatial regions of network coverage. UEs perform radar sensing for various reasons, depending upon the nature of the UE or the equipment with which it is associated. For example, an automobile or other vehicle includes an embedded UE that performs radar sensing for environmental awareness or obstacle detection as part of autonomous navigation or vehicle safety. As another example, a UE used for mobile broadband communications employs radar sensing to detect its proximate environment and adjusts the directional sensitivity of its transmitter or receiver to avoid directions that it senses as blocked.

Multiple challenges arise with respect to multiple radar UEs operating within proximity of one another or, more generally, with respect to multiple UEs operating within network coverage. “Within network coverage” means that a UE is at a location where the wireless communication network provides signal levels sufficient for connectivity to the network or a location where transmissions by the UE represent a possible source or interference with respect to other UEs using the network or to one or more radio access nodes of the network.

Known examples of coordinating or otherwise managing multiple radar devices include the approach seen in U.S. Pat. No. 10,567,972. Particular examples of coordinating radar usage of communication resources include the approaches seen in U.S. Pub. Nos. 2020/0036487 Al and WO 2022/028057 Al. Challenges remain, however, regarding efficient, practical implementation of the coordination and management of shared usage of communication resources for communications and radar operations.

SUMMARY

One embodiment comprises a method of operation by a user equipment (UE) with respect to a wireless communication network. The terms “UE”, “User Equipment”, and “wireless communication device” are interchangeable unless otherwise noted, and the example method includes the UE: communicating a radar request to a radio network node via a random access (RA) procedure performed between the UE and the radio network node. Another embodiment comprises a UE configured for operation with a wireless communication network. The UE includes communication interface circuitry configured to send and receive wireless communication signals, and further includes processing circuitry operatively associated with the communication interface circuitry. The processing circuitry is configured to communicate a request for radar resources to a radio network node via a random access procedure performed between the UE and the radio network node.

Yet another embodiment comprises a method of operation by a radio network node in a wireless communication network. The method includes the radio network node carrying out a RA procedure with a UE, where the RA procedure includes the radio network node receiving a RA request from the UE, indicating that the UE is requesting a grant of radar resources.

A related further embodiment comprises a radio network node configured for operation in a wireless communication network. The radio network node includes communication interface circuitry configured to send and receive wireless communication signals, and further includes processing circuitry operatively associated with the communication interface circuitry. The processing circuitry is configured to carry out a RA procedure with a UE, where the RA procedure includes the radio network node receiving a RA request from the UE, indicating that the UE is requesting a grant of radar resources.

Of course, the present invention is not limited to the above features and advantages. Indeed, those skilled in the art will recognize additional features and advantages upon reading the following detailed description, and upon viewing the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure l is a block diagram of a wireless communication network and corresponding wireless communication devices, according to an example embodiment.

Figure 2 is a block diagram of allocations of communication resources for radar utilization, according to an example embodiment.

Figure 3 is a diagram of example details for mapping respective radar characteristics or attributes to particular communication resources.

Figure 4 is a diagram of an example transmit beamforming configuration of a radio network node.

Figure 5 is a block diagram of example implementation details for a wireless communication device and a radio network node.

Figure 6 is a logic flow diagram of a method of operation by a wireless communication device, according to an example embodiment. Figure 7 is a block diagram of an example implementation of processing circuitry of a wireless communication device.

Figure 8 is a block diagram of another example implementation of a wireless device.

Figure 9 is a logic flow diagram of a method of operation by a radio network node according to an example embodiment.

Figure 10 is a block diagram of another example implementation of a radio network node.

Figure 11 is a block diagram of an example implementation of processing circuitry of a radio network node.

Figure 12 is a block diagram of another example implementation of a radio network node.

Figure 13 is a signal flow diagram of signaling for a wireless communication device to request radar resources from a radio network node, according to an example embodiment.

Figure 14 is a signal flow diagram of signaling going between a wireless communication device and a radio network node, according to an example radar random access procedure.

DETAILED DESCRIPTION

Figure 1 is a block diagram of an example wireless communication network 10 that provides one or more types of communication services to wireless communication devices 12, such as by acting as an access network that communicatively couples respective ones of the wireless communication devices 12 to other devices or systems. For example, the communication network 10 communicatively couples to one or more external networks 14, such as the Internet or other Packet Data Network (PDN) that provides access to other devices or systems, such as the host computer 16 shown in the depicted example. The host computer 16 comprises, for example, a computer server that provides one or more types of data or communication services.

The communication network 10 comprises, for example, a wireless communication network, such as a cellular network operating according to Third Generation Partnership Project (3 GPP) specifications. In the depicted example, the wireless communication network 10 — network 10, hereafter — includes a Radio Access Network (RAN) 20, which includes one or more radio network nodes (RNNs) 22 operating as radio access points for communicatively coupling to respective wireless communication devices 12 — devices 12, hereafter. As noted, “UE” or “User Equipment” are interchangeable terms for a device 12. The example RNN 22 includes an antenna system 24, which is a beamforming antenna assembly in one or more embodiments, e.g., to provide transmit beamforming for downlink (DL) data and control signals that are transmitted directionally, or to provide receive beamforming for uplink (UL) data and control signals that are received directionally. Here and elsewhere, the word “or” means one or the other or both, unless otherwise specified or clear from the context.

Further included in the network 10 is a core network (CN) 26, which controls communication services provided by or through the network 10, controls access and authorization of respective devices 12, manages mobility of devices 12 within the network 10, and provides routing and address handling for data flowing between respective ones of the devices 12 and the external network(s) 14. Various network functions (NFs) 28 combine or cooperate to provide overall control of communication data flows through the network 10 and to provide overall management of the devices 12. At least some such functions may be implemented as virtualized network functions (VNFs) 29, in which the logical functionality of the respective functions is instantiated in a virtual machine running on a host computer system.

One or more of the devices 12 are radar devices that perform one or more types of radarsensing operations during which each such device transmits signals in a frequency range usable for radar sensing and senses return reflections. Of particular interest herein is the use of communication resources associated with the network 10 for radar operations by one or more of the devices 12. Other points of interest include signaling and procedures by and between the devices 12 and the RNNs 22, regarding requests for radar resources, granting of such requests, and overall management or coordination of radar resources. As noted earlier, a “radar resource” is a communication resource utilized for radar operations.

Figure 2 illustrates communication resources 30, where the reference number “30” is used to refer to any given communication resource in a singular sense or any given pool, block, set, or group of communication resources in a plural sense. The communication resources 30 are, as noted, comprised of frequencies or frequency bands. For example, different subcarriers of an OFDMA carrier represent distinct communication resources 30. However, different communication resources 30 may be distinguished in one or more other “domains,” such as the time domain or in the code domain or in the spatial domain. For example, frequency A at symbol time 1 distinguishes from frequency A at symbol time 2, frequency A using code 1 distinguishes from frequency A using code 2, and frequency A used in spatial direction 1 distinguishes from frequency A used in spatial direction 2. Additional distinctions or combinations of distinctions are possible with respect to defining different communication resources 30 and it should be understood that the pool or universe of communication resources 30 illustrated in Figure 2 may or may not be homogenous — i.e., it may comprise different types of resources in addition to frequency, such as time multiplexing or code multiplexing. Broadly, a communication resource 30 can be understood as a distinct signal transmission resource, such that different transmissions on different communication resources are distinct with respect to each other.

The network 10 provides for managed use of some communication resources 30 as radar resources — i.e., communication resources 30 that are used for the transmission of radar signals rather than communication signals. For example, the network 10 reserves some communication resources 30 as baseline resources 32, which are reserved for radar utilization. Baseline resources 32 may be defined for each radio network node 22 and further for respective spatial directions, e.g., there may be different baseline resources 32 corresponding to different defined beamforming directions that are used by a radio network node 22 for transmitting synchronization and reference signals used by devices 12 for synchronizing with and connecting to the radio network nodes 22. There may be resource reuse among the radio network nodes 22 and among the respective beam directions.

Further, there may be dynamic resources 34, which are communication resources 30 that are allocated for radar utilization on a dynamic basis, e.g., based on devices 12 requesting radar resources and the involved radio network node(s) 22 granting such requests. Note that the dynamic resources 34 may overlap partially or wholly with the baseline resources 32. Thus, in one or more embodiments or operating scenarios, the dynamic resources 34 are coextensive with the baseline resources 32, meaning that the baseline resources 32 are used only on a request/grant basis. In other embodiments or operating scenarios, a portion of the baseline resources 32 is usable for radar operations without need for request/grant signaling, while a remaining portion is usable only through request/grant signaling. In yet other embodiments, the dynamic resources 34 are different than the baseline resources 32.

Further, certain communication resources 30 are predesignated as signaling resources 36, to be used by devices 12 for sending requests for radar resources to the network 10. As an example, there may be a plurality of defined random access (RA) preambles, and a first plurality of such RA preambles is reserved for use in making conventional RA channel (RACH) transmissions to the network 10, i.e., for establishing a connection with the network 10, while a second plurality of the RA preambles is reserved for use in performing a radar RA.

A radar RA distinguishes from a conventional RA in that it operates as a request for radar resources and it may or may not also operate as a request for a communication connection with the network 10. Indeed, in at least one embodiment, some RA preambles are reserved for requesting radar resources without establishing a connection to the network 10, while other RA preamble are reserved for jointly requesting radar resources and connection establishment. In addition, or as an alternative, to the signaling resources 36 being reserved RA preambles, they may be defined in terms of specific transmission occasions or windows, e.g., certain occasions are used for transmitting RA preambles as radar requests and certain other occasions are used for transmitting RA preambles as conventional connection requests. Unless otherwise noted herein, all discussions of random access herein, including RA preambles and RA procedures, refer to radar RA, unless otherwise noted or plain from the context.

Thus, techniques disclosed herein advantageously repurpose or extend the random access concept for requesting radar resources, with such repurposing or extending providing a “lean” mechanism for devices 12 to request radar resources and an efficient way for the network 10 to control, track, or otherwise monitor utilization of radar resources by respective devices 12 operating within the area(s) in which the network 10 provides coverage. “Lean” in this context means minimal signaling and “radar resource” means any communication resource 30 of the network 10 that is at least temporarily utilized for radar-sensing operations.

Figure 3 illustrates an example of signaling resources 36, with the diagram depicting distinct transmission resources defined by respective frequencies and times. In one or more example embodiments, each resource maps to one or more characteristics associated with radar sensing, such as needed bandwidth. A device 12 having knowledge of the mappings or correspondence between individual ones of the signaling resources 36 and the respective characteristics represented by each such resource efficiently communicates its radar request to the network 10 by transmitting on the resource that maps to the characteristic(s) that match its radar-sensing needs.

Figure 4 illustrates an example RNN 22 of the network 10, wherein the RNN 22 is configured to use transmit beamforming, wherein it performs directional transmission of its radio signals. In the illustrated example, the RNN 22 covers an aggregate area using five beams 40-1, 40-2, 40-3, 40-4, and 40-5. Each beam 40 covers a respective angular range in terms of horizontal or elevational angles. Communication resources 30 repurposed for radar utilization with respect to one beam coverage area may be reused in one or more other beam coverage areas.

Figure 5 illustrates a RNN 22 and a device 12 according to example embodiments. Other arrangements yielding substantially the same device functionality described herein are possible. The device 12 includes communication interface circuitry 50, which includes transmit (TX) circuitry 52 and receive (RX) circuitry 54 that couple to one or more TX/RX antennas 58 via an antenna interface 56. The TX/RX circuitry 52/54 operates as a radio transceiver that is configured for transmitting and receiving signaling according to the specifications applicable to the network 10, with the radio transceiver further operable to perform radar sensing — i.e., to transmit signals at one or more frequencies and monitor for return reflections of the transmit signal(s).

The antennas 58 may comprise one or more antenna arrays configured for transmit or receive beamforming. For transmit beamforming, a plurality of antenna elements and beamforming circuitry in the device 12 is configured to transmit a weighted version of the same signal from each antenna element. The element weightings comprise different phase and attenuation values that are calculated to yield the desired beam direction and shape in the far field, based on constructive and destructive superpositions of the per-element signals. Receive beamforming operates similarly, but with respect to incoming signals impinging on the antenna elements and creating a corresponding plurality of per-element received signals that are weighted either in the analog or digital domain, to impart a calculated directional sensitivity for signal reception at the device 12.

The device 12 further includes processing circuitry 60 that is configured to carry out the device operations described herein, meaning that the processing circuitry 60 by itself or in cooperation with other circuitry in the device 12 is configured to control the device 12 to carry out the device operations described herein. Broadly, the processing circuitry 60 comprises fixed circuitry or programmatically-configured circuitry or some combination of both.

In at least one embodiment, the processing circuitry 60 comprises one or more microprocessors or other digital processors that are specially adapted to operate as the processing circuitry 60, based on the execution of computer program instructions stored in one or more types of computer readable media. Correspondingly, the device 12 in one or more embodiments includes storage 62 that stores one or more computer programs 64 or configuration data 66. Configuration data 66 may be pre-provisioned or provided by the network 10 during live operation of the device 12. In one example, the configuration data 66 at least includes information received from the network 10 about the allocations or reservations of communication resources 30 for utilization in radar-sensing operations. The storage 62 comprises one or more types of computer-readable media, such as a mix of volatile storage for program execution and data processing, and non-volatile storage for longer term program and data storage. Examples include any one or more of SRAM, DRAM, EEPROM, FLASH, Solid State Disk (SSD), etc.

In the context of Figure 5, a wireless communication device is configured for operation with a wireless communication network, e.g., a device 12 is configured for operation with respect to the network 10, meaning that it is configured to connect to the network 10 according to the communication-signal frequencies, structure, and protocols that define the “air interface” provided by the network 10. The device 12 may be credentialed or otherwise authorized to access the network 10, e.g., it may be associated with a subscriber account eligible to use the network 10 either on a home network or visited network basis.

Included in the example device 12 is communication interface circuitry 50 that is configured to send and receive wireless communication signals. Particularly, the communication interface circuitry 50 includes transmit circuitry 52 configured to transmit uplink (UL) signals for reception by one or more radio network nodes 22 of the network 10 and includes receive circuitry 54 configured to receive downlink (DL) signals from respective ones of the radio network nodes 22. Such circuitry may be referred to as a radio modem or cellular-network modem and it includes analog circuitry for transmitting radiofrequency (RF) signals via one or more antennas 58 and for receiving RF signals via the one or more antennas 58. Interface circuitry 56 may be used to interface the transmit and receive circuitry 52 and 54 with the antennas 58, which may comprise antenna arrays or panels comprising one or more pluralities of antenna elements In at least one embodiment, one or both of the transmit circuitry 52 and receive circuitry 54 includes analog, digital, or hybrid beamforming circuitry, for transmit beamforming, receive beamforming, or both.

Further, in a least one embodiment, the communication interface circuitry 50 in one or more devices 12 is re-used for radar operations, e.g., for sensing proximate objects, or one or more of the devices 12 include dedicated radar circuitry that operates at frequencies used by the network 10 for communications. Correspondingly, processing circuitry 60 of such a device 12 is configured to request allocations of radar resources and operate according to such allocations.

In more detail, such a device 12 includes processing circuitry 60 that is operatively associated with the communication interface circuitry 50 of the device. “Operatively associated” means that the processing circuitry 60 uses the communication interface circuitry 60 to send and receive wireless communication signals that convey data or control information that is generated or used by the processing circuitry 60.

In an example embodiment, the processing circuitry 60 of a device 12 is configured to decide to request an allocation of radar resources from a radio network node 22 of the network 10 that allocates selected communication resources 30 of the network 10 for utilization as radar resources. The processing circuitry 60 according to the example embodiment is further configured to communicate the radar request to the radio network node 22 via a random access (RA) procedure performed between the device 12 and the radio network node 22. Here and elsewhere in this disclosure, references to RA procedures shall be understood as referencing radar RA procedures, which distinguish from conventional RA procedures in multiple ways. For example, the RA procedure(s) of interest herein function as requests for allocations of radar resources and do not necessarily operate as requests to connect to the network 10 for communication services.

In one or more example implementations, the processing circuitry 60 includes or is associated with storage 62 that comprises one or more types of computer-readable media. For example, the storage 62 stores one or more computer programs 64 or stores one or more types of configuration data 66, for use by the processing circuitry 60. However implemented, in one or more embodiments, the processing circuitry 60 is configured to communicate a radar request to a radio network node 22 via a random access (RA) procedure performed between the device 12 and the radio network node 22. Communicating the radar request to the radio network node 22 comprises the device 12 requesting an allocation of radar resources, and the processing circuitry 60 is configured to receive a RA response from the radio network node 22, indicating the allocation of radar resources.

With respect to requesting the allocation of radar resources, in one or more embodiments, the processing circuitry is configured to request the allocation in response to the device 12 determining that baseline resources allocated for utilization as radar resources are unsuitable. As one example, the processing circuitry 60 is configured to determine the unsuitability based on detecting interference at the device 12 with respect to the baseline resources or determine that the baseline resources do not meet one or more requirements of radar operation by the device 12. For example, the processing circuitry 60 determines that the baseline resources 32 at issue do not offer sufficient bandwidth for the radar sensing to be performed.

The processing circuitry 60 in one or more embodiments is configured to identify the baseline resources 32 from information contained in a System Information Block (SIB) received from a radio network node 22. Broadcasting such information in one or more SIBs represents a particularly efficient approach for the radio network node 22 to inform devices 12 operating within its coverage area(s) as to which communication resources from the overall set or universe of communication resources 30 associated with the radio network node 22 are provisioned or otherwise included in baseline resources 32 that are designated for radar utilization.

In at least one embodiment, the radio network node 22 is configured to transmit 46 radar- related network configuration information indicating at least one of: baseline resources allocated for radar usage; or one or more parameters to use when performing RA procedures to request grants of radar resources. Correspondingly, the device 12 is configured to use such information to identify baseline resources and/or identify one or more parameters to use when performing an RA procedure to request radar resources.

In one or more embodiments or under first example operating circumstances, the RA procedure is a two-step procedure comprising the device 12 transmitting a RA request comprising the radar request and receiving a RA response (RAR) from the radio network node 22 that comprises a radar grant indication. Because the RA request is a radar RA request, it may also be referred to as a rRA request and the RA procedure may be referred to as a rRA procedure.

In one or more other embodiments or under second operating circumstances, the RA procedure is a four-step procedure comprising the device 12 transmitting a RA request that indicates that the RA procedure is for requesting radar resources, the device 12 receives a RAR from the radio network node 22 that indicates availability of radar resources, the device 12 transmits a message indicating request details, and the device 12 receives a message indicating grant details.

The processing circuitry 60 is configured to indicate to the radio network node 22 that the RA procedure is for requesting radar resources, for example, based on the processing circuitry 60 transmitting a RA request using a communication resource 30 that is designated for performing RAs for the purpose of requesting radar resources. In the context of Figure 2, for example, the signaling resources 36 comprise certain RA preambles or RA transmission times or other communication resources 30 that are predesignated for use in requesting radar resources — i.e., a RA request transmitted using any such resources is understood by the radio network node 22 implicitly as a request for radar resources. Moreover, as shown in Figure 3, different ones of such signaling resources 36 may be mapped or linked to different radar attributes or characteristics, such that the processing circuitry 60 of the device 12 chooses one of the signaling resources 36 for transmitting a RA request, to indicate implicitly that the RA request is a request for radar resources and choose the particular one(s) of such resources to indicate implicitly particular resource requirements.

For example, one or more first random access preambles are designated for initiating connection to the wireless communication network, one or more second random access preambles are designated for requesting radar resources without initiating connection to the wireless communication network, and one or more third random access preambles are designated for jointly initiating connection to the wireless communication network and requesting radar resources, and wherein the processing circuitry is configured to choose either one of the one or more second random access preambles or one of the one or more third random access preambles for requesting radar resources, in dependence on whether connection to the wireless communication network is needed by the device 12.

In one or more embodiments, the processing circuitry 60 is configured to receive an indication of granted radar resources from the radio network node 22 during the RA procedure and perform a radar operation using one or more of the granted radar resources. Here, saying that the processing circuitry 60 is configured to receive the indication means that the processing circuitry 60 is configured to use the communication interface circuitry 50 to monitor for reception of signaling conveying the indication and to interpret such signaling.

The processing circuitry 60 in one or more embodiments is configured to use the granted radar resources subject to grant validity information transmitted by the radio network node 22. The grant validity information indicates one or more of a spatial constraint or a temporal constraint, with the processing circuitry 60 operating the device 12 according to the indicated constraints — i.e., limiting utilization of the granted radar resources in keeping with the constraint s).

The processing circuitry 60 in one or more embodiments is configured to, subsequent to being granted radar resources by the radio network node 22 in response to the radar request, terminate usage of the granted radar resources and transmit an indication of the termination, for receipt by the radio network node 22. Providing termination signaling to the radio network node 22 enables the radio network node 22 to track more accurately the communication resources 30 that are being utilized as radar resources in any given physical area.

Figure 6 illustrates a method 600 of operation by a device 12 for requesting an allocation of radar resources from a radio network node 22 of a wireless communication network 10 that allocates selected communication resources of the wireless communication network 10 for utilization as radar resources. The method 600 comprises the device 12 communicating (Block 604) a radar request to the radio network node 22 via a random access (RA) procedure performed between the device 12 and the radio network node 22.

The method 600 may include an initial step or operation of the device 12 obtaining (Block 602) information regarding the allocation or designation of communication resources for radar-related usage. For example, the device 12 obtains information indicating communication resource allocations or designations regarding radar requests and utilization. This operation comprises, for example, the device 12 receiving signaling broadcasted by the radio network node 22 that indicates baseline resources 32 allocated by the radio network node 22. The same or additional signaling may also indicate signaling resources 36 to be used by the device 12 for requesting radar resources using an RA procedure. As noted earlier, any reference to RA procedures in this disclosure are understood as references to radar RA procedures unless otherwise stipulated. A radar RA procedure mimics conventional RA procedures with key differences, e.g., radar RA procedures may or may not result in the device 12 connecting to the network 10, the signaling from the device 12 explicitly or implicitly indicates that the RA signaling is for the purpose of requesting radar resources, and the signaling from the involved radio network node 22 indicates grant information, such as whether the request is granted and particular communication resources dynamically granted to the device 12 for radar utilization.

In one embodiment or under first example operating conditions, the RA procedure is a two-step procedure comprising the device 12 transmitting a RA request comprising the radar request and receiving a RA response from the radio network node 22 that comprises a radar grant indication. The RA request comprises, for example, the transmission by the device 12 of a RA preamble that is designated as a radar-request preamble. Further, in at least one embodiment, different ones among a plurality of radar-request preambles map to different request information, e.g., different ones of the preambles map to different request options regarding the needed bandwidth, etc., and the device 12 transmits the preamble that maps to its radar needs.

In another embodiment, the RA procedure is a four-step procedure comprising the device 12 transmitting a RA request (a “Msgl”) that indicates that the RA procedure is for requesting radar resources, the device 12 receiving a RA response (a “Msg2”) from the radio network node 22 that indicates availability of radar resources, the device 12 transmitting a message (a “Msg3”) indicating request details, and the device 12 receiving a message (a “Msg4”) from the radio network node 22 that indicates grant details.

In at least one embodiment, communicating (Block 604) the radar request to the radio network node 22 comprises the device 12 requesting an allocation of radar resources, with the method 600 further comprising the device 12 receiving a RA response indicating the allocation of radar resources.

Requesting the allocation of radar resources is performed in the method 600, for example, in response to the device 12 determining that baseline resources allocated for utilization as radar resources are unsuitable. As one example, the device 12 determines the unsuitability based on detecting interference at the device 12 with respect to the baseline resources or determining that the baseline resources do not meet one or more requirements of radar operation by the device 12. The device 12 identifies the baseline resources, for example, from information contained in a SIB received from the radio network node 22. Broadly, the step(s) or operation(s) labeled as Block 604 in the method 600 may be performed on a triggered basis. That is, in at least one embodiment, the device 12 performs the operation(s) of Block 604 in response to the device 12 detecting fulfillment of a triggering condition, such as determining that the baseline resources do not match its radar needs or that the baseline resources are occupied or otherwise experiencing more than a threshold level of interference, as detected at the device 12.

Figure 7 illustrates an example implementation of the processing circuitry 60 of a device 12 that is configured to perform the method 600 or any of the various device-side operations described herein. Broadly, the processing circuitry 60 comprises fixed circuitry or programmatically-configured circuitry or both, with Figure 7 illustrating an embodiment where the processing circuitry 60 comprises one or more microprocessors 70 that are specially adapted to perform the device-side operations described herein — i.e., to control or initiate the control of the overall device 12, to perform the described operations — based on the execution of computer program instructions 74 stored in a memory 72. The computer program instructions 74 are contained, for example, in the computer program(s) 64 held in the storage 62, as seen in Figure 5, where the memory 72 comprises at least a part of the storage 62.

Figure 8 illustrates another example implementation of a device 12, wherein the device 12 comprises a number of processing modules or units, with the understanding that each such processing module comprises functional logic implemented using underlying physical circuitry. The illustrated modules include an obtaining module 80, a deciding module 82, a communicating module 84, and an operating module 86. The obtaining module 80 is configured to obtain information regarding baseline resources 32 allocated for radar utilization, or information regarding predesignated communication resources that are for use in requesting radar resources. The deciding module 82 is configured to decide when the device 12 should transmit a request for radar resources to a radio network node 22. The communicating module 84 is configured to carry on communications according to the air interface requirements of the network 10. The operating module 86 is configured to carry out radar- sensing operations using allocated communication resources.

Turning back to Figure 5, the example radio network node 22 includes communication interface circuitry 90, which includes transmit (TX) circuitry 92-1 and receive (RX) circuitry 94- 1 that couple to one or more TX/RX antennas 98 via an antenna interface 96. The TX/RX circuitry 92-1/94-1 operates as one or more radio transceivers configured for transmitting and receiving signaling according to the specifications applicable to the network 10, i.e., they provide for uplink and downlink signaling with respective devices 12. The antennas 98 may comprise one or more antenna arrays configured for transmit or receive beamforming and represent one example implementation for the antenna system 24 introduced in Figure 1. For transmit beamforming, there are a plurality of antenna elements and beamforming circuitry in the radio network node 22 that is configured to transmit a weighted version of the same signal from each antenna element. The element weightings comprise different phase and attenuation values that are calculated to yield the desired beam direction and shape in the far field, based on constructive and destructive superpositions of the per-element signals. Receive beamforming operates similarly, but with respect to incoming signals impinging on the antenna elements and creating a corresponding plurality of per-element received signals that are weighted either in the analog or digital domain, to impart a calculated directional sensitivity for signal reception at the radio network node 22.

The communication interface circuitry 90 further comprises one or more transmitters 92- 2 and one or more receivers 94- 2 that are configured to provide inter-node network communication capability to the radio network node 22. For example, the radio network node 22 exchanges signaling with one or more other radio network nodes 22 and one or more nodes in the CN 26.

Processing circuitry 100 of the radio network node 22 is configured to carry out the node operations described herein, meaning that the processing circuitry 100 by itself or in cooperation with other circuitry in the radio network node 22 is configured to control the radio network node 22 to carry out the node operations described herein. Broadly, the processing circuitry 100 comprises fixed circuitry or programmatically-configured circuitry or some combination of both.

In at least one embodiment, the processing circuitry 100 comprises one or more microprocessors or other digital processors that are specially adapted to operate as the processing circuitry 100, based on the execution of computer program instructions stored in one or more types of computer readable media. Correspondingly, the radio network node 22 in one or more embodiments includes storage 102 that stores one or more computer programs 104 or configuration data 106. Configuration data 106 may be pre-provisioned or dynamically determined, e.g., it may be determined in cooperation with neighboring radio network nodes 22 or otherwise provided by a central entity, such as an Operations & Maintenance (0AM) node

In one example, the configuration data 106 specifies the allocations or reservations of communication resources 30 for utilization in radar-sensing operations. The storage 102 comprises one or more types of computer-readable media, such as a mix of volatile storage for program execution and data processing, and non-volatile storage for longer term program and data storage. Examples include any one or more of SRAM, DRAM, EEPROM, FLASH, Solid State Disk (SSD), etc.

In the context of Figure 5, a radio network node 22 is configured for operation in a network 10, meaning that it is configured to provide uplink and downlink signaling and controls for respective devices 12 according to the protocols and specifications applicable to the network 10. Included in the example radio network node 22 is communication interface circuitry 90 that is configured to send and receive wireless communication signals, and processing circuitry 100 that is operatively associated with the communication interface circuitry 90.

Based on the configuration of the processing circuitry 100, the radio network node 22 is operative to manage the allocation of communication resources for utilization as radar resources. For example, the radio network node 22 manages the allocation with respect to the areas in which it provides network coverage.

The processing circuitry 100 is configured to carry out a RA procedure with a device 12, where the RA procedure comprises the radio network node 22 receiving a random access request from the device 12, indicating that the device 12 is requesting a grant of radar resources. Further, the processing circuitry 100 may be configured to send a radar grant indication for the device 12, as further operations performed in the RA procedure. The processing circuitry 100 in one or more embodiments is configured to determine the radar grant indication in dependence on communication resource availability.

As suggested in Block 902, in one or more embodiments, the radio network node 22 manages allocation of communication resources for use as radar resources; for example, the radio network node 22 manages baseline resources for radar utilization.

Broadly, the network 10 needs to assess making radar grants based on required total communication needs (which it knows from its own scheduling operations), to balance resource usage between communication usage and radar usage, and determine particular radar grants based on making sure no conflict or excess interference arises between radar users.

In one or more embodiments, the processing circuitry 100 is configured to determine the resource availability according to a spatial reuse scheme, in which a same communication resource is reusable for radar operations in different beam directions used by the radio network node 22. See Figure 4 for an example arrangement of directional beams.

The processing circuitry 100 in one or more embodiments is configured to allocate baseline resources 32, for utilization by devices 12 as radar resources. Correspondingly, the request for a grant of radar resources applies to communication resources 30 allocated as the baseline resources 32, and the processing circuitry 100 is configured to determine the communication resource availability with respect to the baseline resources 32. In at least one such embodiment, allocating the baseline resources 32 comprises allocating baseline resources 32 corresponding to different beam directions used by the radio network node 22, and the processing circuitry 100 is further configured to transmit SIBs in different beam directions used by the radio network node 22, with each SIB indicating the corresponding baseline resources 32. Still further, in at least one such embodiment, the processing circuitry 100 is configured to track utilization of communication resources for radar on a per beam direction basis and adjust the baseline resources 32 corresponding to each beam direction in dependence on the tracked utilization and communication needs associated with the beam direction.

As for the radio network node 22 performing a RA procedure in response to receiving the random access request, the processing circuitry 100 is configured to recognize the random access request as being a request for radar resources, for example, based on the random access request using a communication resource designated for use by devices 12 when performing random accesses for the purpose of requesting radar resources. See, e.g., the signaling resources 36 shown in Figure 2. In at least one such embodiment, different random access preambles are mapped to different radar grant configurations, and the processing circuitry 100 is configured to select the radar grant configuration mapped to the random access preamble received as the random access request and determine a radar grant for the device 12 UE according to the selected radar grant configuration.

Figure 9 illustrates a method of operation by a radio network node 22 configured for operation in a network 10. The method 900 includes the radio network node 22 carrying out (Block 904) a RA procedure with a device 12, wherein the RA procedure comprises the radio network node 22 receiving a random access request from the device 12, indicating that the UE is requesting a grant of radar resources. The RA procedure may further comprise the radio network node 22 sending a radar grant indication for the device 12. In at least one embodiment, the method 900 includes the radio network node 22 determining the radar grant indication in dependence on communication resource availability.

The radar grant indication is determined by the radio network node 22, for example, in dependence on communication resource availability and the total amount of radar resource usage. For example, if no resources are available, or if there are insufficient resources available or only inappropriate resources available, the radar grant indication may be negative — i.e., no radar resources granted. On the other hand, if resources are available to accommodate the request, the grant indication will be positive. The method 900 may also include the radio network node 22 managing (Block 902) the baseline resources 32 for radar utilization — such “managing” may be an ongoing process or a periodically repeated process. For example, the radio network node 22 broadcasts signaling that indicates the communication resources 30 that are comprised in the baseline resources 32 and tracks utilization of those resources by respective devices 12. The radio network node 22 may, for example, decrease or increase the amount or number of baseline resources 32 based on the utilization level, which may be an averaged or filtered value, so that decisions are made based on longer-term utilization levels.

Figure 10 illustrates another example embodiment of a radio network node 22, wherein the radio network node 22 comprises a central unit or CU 110 that is communicatively coupled to one or more remote radio units or RRUs 112, e.g., RRUs 112-1 and 112-2 are shown. The CU 110 may contain the functional logic to carry out the network-node operations described herein and may be cloud-based or otherwise virtualized, with the RRUs 112 acting as radio transmission/reception points and containing the transmit and receive circuitry and antenna system(s) for transmitting downlink signals and receiving uplink signals.

Figure 11 illustrates an example embodiment of the processing circuitry 100 of a radio network node 22, where the processing circuitry 100 is at least partially implemented via one or more microprocessors 120 or other digital processors that is/are specially adapted to carry out the network-node operations described herein, based on the execution of computer program instructions 124 stored in a memory 122. The computer program instructions 124 may be included in the one or more computer programs 104 illustrated in Figure 5 and, similarly, the memory 122 may comprise at least a portion of the storage 102 illustrated in Figure 5.

Figure 12 illustrates another embodiment of a radio network node 22, wherein the radio network node 22 comprises a number of processing units or modules. Example modules include a managing module 130 that is configured to manage allocations of communication resources for radar utilization, a receiving module 132 that is configured to receive requests for radar resources, and a performing module 134 that is configured to perform radar-request granting, e.g., carry out a RA procedure in which the involved device 12 requests radar resources.

Figure 13 illustrates example signaling going between a radar UE and a network node, e.g., going between a device 12 that performs radar operations and a radio network node 22 that grants radar resources. The radar UE determines or otherwise defines the characteristics of the required radar resources, such as the required frequency range, radar-signal bandwidth, etc. Then, assuming that different RA preambles for requesting radar resources are predesignated, with each corresponding to different required characteristics, the radar UE selects the designated RA preamble that matches or most closely corresponds to its requirements and transmits it.

The network node receives the preamble transmission, recognizes it as a radar request and correspondingly evaluates resource availability. Based on the evaluated resource availability, the network node generates a RA response that includes a radar grant indication and transmits the response for the radar UE. The radar grant indicates, for example, the particular resources granted. Such signaling may be understood as an example of a two-step RA procedure for requesting radar resources. The radar UE may or may not want connectivity with the network 10. For example, one or more predesignated RA preambles may be used for requesting radar resources without acquiring network connectivity and one or more other predesignated RA preambles may be used for requesting radar resources and requesting network connectivity.

Figure 14 illustrates a four-step RA procedure for requesting radar resources, e.g., with the first message, Msgl, going from the radar UE to the network node as a request for radar resources. Rather than Msgl implicitly indicating specific radar characteristics required by the radar UE, such information may be carried in the third message, Msg3. That is, in response to Msgl, the network node transmits Msg2 as a RA response, and the radar UE uses Msg3 to identify particulars of its radar request, and the network node uses Msg4 to indicate radar grant details.

With the above details in mind, it will be appreciated that the disclosure provides various examples for allocating communication resources — e.g., time, frequency, spatial resources — for radar operations, e.g., during uplink intervals. Because the allocated radar resources may overlap with communication resources — i.e., communication resources used for communications signaling — the disclosure presents techniques for preventing radar operations by any given radar UE from interfering with radar operations of other radar UEs and from interfering with UEs involved in “normal” network-based communications. Radar resource allocations and radar requests may be managed on a per beam basis, e.g., in beam coverage areas corresponding Synchronization Signal Block (SSB) beam directions used by a 5G radio network node 22.

A radar UE can request radar sensing resources via a random-access-like process, and the network can grant or deny the request. The request process may use established principles for conventional random access, e.g., the use of preamble structures and 4-step or 2-step RACH procedures, but the components may be at least partially redefined or reconfigured to distinguish them from conventional RA resource allocation and new mappings of used resources to requested radar resource configurations, different contents in Msg2-4, different Msg (RAR) search space definitions, etc. Because radar sensing is directional, it is possible to perform the process for specific uplink beam directions using the corresponding SSB, built upon beam correspondence. In one or more embodiments, a radar grant may be valid for other SSB directions — that is, the radar grant may indicate directions in which it is valid for the requesting device 12 to use the granted radar resources for radar-signal transmission.

Each SSB direction may have dedicated RACH resources in a time-division-multiplex (TDM) fashion, so that a radio network node 22 can individually grant or deny requests within any given SSB beam direction. The radar resource allocation via random access mechanism may thus be for a specific SSB beam direction. (Resource requests and grants implementations in communication are typically not direction-specific, although resource reuse is possible to configure by the BS with NR standards.) Network can grant resources, which are suitable for multiple radar sensing occasions.

In one or more example embodiments, each SSB beam direction has communication resources 30 that are allocated as associated baseline resources 32 for radar utilization, i.e., the baseline resources 32 are communication resources 30 to be used as radar resources. In at least one such embodiment, a radar UE may utilize one or more of the baseline resources 32 without requiring a grant, such that the radar UE needs to send requests for radar resources only when it determines that the baseline resources 32 are not sufficient or are otherwise not suited for its radar operations. In one or more other embodiments, although the baseline resources 32 are predesignated, their usage requires a specific grant. As a further variation, a radio network node 22 may grant specific resources from among the baseline resources 32 or may grant communication resources 30 that are outside of the baseline resources 32, in dependence on the indicated needs of the radar UE. See Figure 2, indicating that dynamic resources 34 may be among the baseline resources 32 or outside of them.

Thus, in at least one embodiment, a radar UE can request radar resources via a RA process that the radar UE initiates responsive to determining that suitable baseline resources 32 (in time or frequency dimensions) are not available or are not usable due to high interference levels. In this context, a radio network node 22 advertises the baseline resources 32 associated with it by broadcasting a “radar” System Information Block (SIB), for example, where a radar SIB is a SIB that carries radar information. There may be a newly defined, specific type of SIB dedicated to signaling radar information for radar UEs, or radar information may be included in or otherwise appended to an existing type of SIB.

The requests and grants can be associated with the predefined resources in SIB or independent. One advantage of such operations is that the network can monitor and know the amount of active radar UEs that are using radar resources within a certain spatial direction, and it can dynamically change the radar resource allocation in each SSB direction, which means modifying the resources in the SIB or adapting the resources granted dynamically in response to radar requests, based on the needs and available radio resources.

Thus, as an example, a radar UE receives a SIB broadcasted from a radio network node 22, where the SIB identifies baseline resources 32 that are designated for radar usage in an area corresponding to a particular SSB beam direction. The radar UE may then send a RA preamble that indicates that the RA preamble transmission is a request for radar resources. The return grant indication may indicate that the radar UE can use any of the baseline resources 32 as radar resources, or it may indicate specific ones of those baseline resources 32, or it may indicate other or additional resources dynamically determined by the radio network node 22, e.g., based on characteristics indicated by the radar UE.

In at least one embodiment, a transmitted SIB contains one or more options for radar resource locations, which may be specified, e.g., as any one or more of times, periodicities, or frequencies. A radar UE may transmit a radar RA preamble requesting any/all of the resources (option 1) or select a preamble conveying a request for specific resources, e.g., T/F location and/or duration (option 2). The mapping of resource options to RACH preambles (T/F location, sequence/cyclic shift etc.) may be provided in the SIB. The radio network node 22 may indicate a grant in Msg 2 or in Msg 4, depending on whether the RA procedure is a two-step or four-step procedure. The radar RA procedure may alternatively be independent of declared SIB radar resources — i.e., independent of any defined baseline resources 32. The RACH can be used by the device to request and to receive a grant pointing to specific resources based on the radar request. For example, in a four-step RA procedure, Msgl may be a generic request for radar resources, with the involved device 12 using Msg3 to indicate request specifics, and with the radio network node 22 using Msg4 to indicate specifics of the grant. The grant may include a validity period for the grant duration (so that the radio network node 22 can monitor resource usage and avoid accumulating obsolete or expired grants). Validity information may be embedded in the grant explicitly or different validity periods may be declared in the SIB.

The request can include specifics related to its radar usage needed as input to a grant decision like, e.g., periodicity, bandwidth, duration, service criticality and the return grant can be based on the subscription level. Whether a given device 12 or devices 12 perform radar operations using the baseline resources 32 or request additional or other resources depends, for example, on detected interference, the loading on or utilization level of the baseline resources 32, the criticalities of the involved radar operations, etc. A radio network node 22 may transmit System Information (SI) indicating whether radar requests should be used by devices 12 or whether devices 12 should simply perform any needed operations using resources in the baseline resources 32. Also note that the radio network node 22 may poll devices 12 in any of its coverage areas to determine devices that need to perform or are performing radar operations.

In at least one embodiment, radar operations are managed dynamically so that a selected one of the following applies: (1) radar operations by devices 12 are SIB-based, i.e., respective ones of the devices 12 perform radar operations using communication resources identified in the SIB; (2) radar operations by devices 12 are grant-based, i.e., devices 12 must specifically request resources for radar operation; and (3) a first group or class of devices 12 performs radar operations using granted resources while a second class or group of devices 12 performs radar operations using SIB-identified resources. For example, devices 12 that are linked to subscriptions for radar operations use granted resources, or devices 12 for which radar sensing is critical use granted resources.

Note that SIB-identified resources may be sub-divided, e.g., information carried in the SIB may identify a first subset of resources as being available for radar utilization on an as- needed basis without requiring radar request/grant signaling and may identify a second subset of SIB-identified resources as being available only on a request/grant basis. Alternatively, all SIB- identified resources are available for radar utilization without requiring requests/grants and devices 12 that desire other resources must request them. As a further alternative, the SIB identifies a pool of communication resources for radar utilization but all usage of such resources requires requests/grants.

A radio network node 22 may dynamically vary the approach used based on, for example, the number of devices 12 that are radar devices, i.e., the number of devices 12 within one or more of the areas served by the radio network node 22 that have indicated that they perform radar-sensing operations. Such information may be included in capability information or other signaling from individual devices 12. In situations with high resource availability and low risk of conflicting resources or services with lower criticality, the radio network node 22 may indicate that SIB-identified resources are available for radar utilization without request/grant signaling. However, there are instances where the radio network node 22 exercises full control over radar operations, e.g., where there are many devices 12 performing radar-sensing operations or capable of performing radar-sensing operations, or where there are critical radar sensing needs. Again, however, the radio network node 22 may allow some devices 12 to use a pool of communication resources on a contention basis, while other devices 12 use specifically granted communication resources, e.g., to provide a subscribed Quality-of-Service (QoS) with respect to radar-sensing operations. As noted, a radio network node 22 or other entities within the network 10 may designate certain RA preambles as radar-request preambles or may designate certain times for transmitting RA preambles that are interpreted as radar requests.

Further, in one or more embodiments, a radio network node 22 or other entity within the network 10 tracks the numbers of devices 12 that are active with respect to radar-sensing operations and estimates resource needs. To prevent exhaustion of a limited pool of communication resources that are used for radar operations and to maintain an accurate estimate of the number(s) of devices 12 that are active in a radar-sensing perspective, grants may have defined validity periods, allowing older grants to terminate, automatically. Additionally, or alternatively, there may be a dedicated preamble resource or other resource by which the radar UE can indicate that their granted resource is no longer in use. Alternatively, the radar UE can connect and use Radio Resource Control (RRC) signaling, for example, to terminate the granted radar resources. In at least one embodiment, the network 10 is configured with early termination capability, i.e., to terminate a grant of radar resources before any defined expiration of the grant. For example, the radio network node 22 transmits a paging message that terminates the grant before its validity has expired.

In one embodiment, a radio network node 22 is configured to indicate that a specific spatial area for specific time slot duration associated with a SSB or a particular sub-area is reserved for radar sensing, so that devices 12 do not have to request radar grants. To do so, the radio network node 22 may indicate that the baseline resources 32 of all SSB beam directions, i.e., SIB components for each of the cell areas (SSB coverage areas), from each SSB beam direction, so that a device 12 receiving such information knows which communication resources are reserved in the respective spatial areas. As a specific example, each SSB direction has baseline resources 32 reserved for radar utilization and the radio network node 22 transmits in each beam direction signaling indicating the respective baseline resources 32 used in each beam direction. Here, “beam direction” should be understood as referencing the area covered by a respective direction beam of the radio network node 22.

A radio network node 22 or other entity in the network 10 may use various approaches to monitor or otherwise track usage of the allocated radar resources and update them accordingly, e.g., in concert with managing resource allocations for communications signaling. For example, the network entity tracks the number and location of radar UEs, i.e., it tracks the density (e.g., number of UEs per SSB direction), class (i.e., different radar applications such as car or UE with different characteristics such as maximum allowed power) and the radar traffic of the mentioned UEs. For example, a radar UE can use RRC signaling to report its usage of the radar resources to the network 10 so that the network 10 adjusts the radar resource allocation in the SIB based on it. The accuracy depends on the active radar UEs.

As another example, radar UEs request radar resources and the radio network node 22 tracks radar usage according to the radar grants it sends, with such tracking performed on a per SSB direction. The radio network node 22 may adjust the allocations of baseline resources 32 to the respective SSB directions, based on such tracking. If the grants have defined validity periods, the involved resources may be used to make further grants, upon expirations of the involved validity periods. In at least one configuration, a device 12 that performs radar operations using granted resources preemptively requests new resources before expiration of its current grant.

In another embodiment, which is useful in various scenarios, the radio network node 22 senses radar transmissions for a given SSB direction during uplink slots when radar operation is allowed and then estimates resource utilization to update the resource allocations in the SSB direction. This approach works particularly well when radar signals do not interfere with communication signals, e.g., based on allocating different frequencies for communications versus radar-sensing operations, or because of waveform differences. The network node 22 may be configured to estimate utilization of radar resources by treating the sensed radar usage as a predetermined fraction of total radar activity in the coverage area, or an individual SSB coverage area (e.g., based on geometric analysis or dedicated/advanced measurements).

The baseline resources 32 associated with a radio network node 22 may be adapted based on, for example, the number of requests for device-specific radar resource allocation. The adaptive scheme may be based on the premise that devices 12 shall preferably use resources from the baseline resources 32, such as indicated in SIB transmissions. When those resources become insufficient, e.g., too much interference, or because of radar-sensing criticality, a device 12 requests dedicated, device-specific communication resources for radar utilization. Note that a given device 12 desirous of performing radar operations using communication resources 30 of the network 10 may measure radar activity by surrounding devices 12, e.g., by detecting transmissions that are characteristic of radar sensing rather than communications, and it may use such measurements as a basis for deciding whether to use baseline resources or request dedicated resources. Correspondingly, a radio network node 22 may track the number of such requests that it receives over some defined duration, with the tracked number exceeding some first threshold number being taken as an indication that the baseline resources are insufficient. Conversely, if the number of requests is below some lower minimum threshold, the radio network node 22 may decide to reduce the baseline resources 32. Notably, modifications and other embodiments of the disclosed invention(s) will come to mind to one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention(s) is/are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of this disclosure. Although specific terms may be employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

Claims

CLAIMS Claims:

1. A method (600) of operation by a user equipment (UE) (12) for requesting an allocation of radar resources from a radio network node (22) of a wireless communication network (10) that allocates selected communication resources (30) of the wireless communication network (10) for utilization as radar resources, wherein the method (600) comprises: communicating (604) a radar request to the radio network node (22) via a random access (RA) procedure performed between the UE (12) and the radio network node (22).

2. The method (600) of claim 1, wherein communicating the radar request to the radio network node (22) comprises requesting an allocation of radar resources, and wherein the method (600) further comprises receiving a RA response indicating the allocation of radar resources.

3. The method (600) according to claim 2, wherein requesting the allocation of radar resources is performed in response to the UE (12) determining that baseline resources allocated for utilization as radar resources are unsuitable.

4. The method (600) according to claim 3, further comprising determining the unsuitability based on detecting interference at the UE (12) with respect to the baseline resources (32) or determining that the baseline resources (32) do not meet one or more requirements of radar operation by the UE (12).

5. The method (600) according to claim 3 or 4, further comprising, based on receiving radar-related network configuration information transmitted by the radio network node (22), performing at least one of: identifying the baseline resources (32) from the received radar-related network configuration information; or identifying one or more parameters to use for performing the RA procedure from the received radar-related network configuration information.

6. The method (600) according to any one of claims 1-5, wherein the RA procedure is a two-step procedure in which communicating the radar request comprises the UE (12) transmitting a RA preamble designated for use in requesting radar resources, and wherein the RA procedure further comprises the UE (12) receiving a RA response from the radio network node (22) that comprises a radar grant indication.

7. The method (600) according to any of claims 1-5, wherein the RA procedure is a four- step procedure in which communicating the radar request comprises the UE (12) transmitting a RA preamble designated for use in requesting radar resources, and wherein the RA procedure further comprises the UE (12) receiving a RA response from the radio network node (22) that indicates availability of radar resources, the UE (12) responding to the RA response by transmitting a message indicating radar request details, and the UE (12) subsequently receiving a message indicating grant details.

8. The method (600) according to any one of claims 1-7, wherein the UE (12) indicates to the radio network node (22) that the RA procedure is for requesting radar resources by transmitting a RA request using a communication resource (36) designated for performing random accesses for the purpose of requesting radar resources.

9. The method (600) according to any one of claims 1-8, wherein one or more first random access preambles are designated for initiating connection to the wireless communication network (10), one or more second random access preambles are designated for requesting radar resources without initiating connection to the wireless communication network (10), and one or more third random access preambles are designated for jointly initiating connection to the wireless communication network (10) and requesting radar resources, and wherein the method (600) further comprises the UE (12) choosing either one of the one or more second random access preambles or one of the one or more third random access preambles for requesting radar resources, in dependence on whether connection to the wireless communication network (10) is needed by the UE (12).

10. The method (600) according to any of claims 1-9, further comprising receiving an indication of granted radar resources from the radio network node (22) during the RA procedure and performing a radar operation using one or more of the granted radar resources.

11. The method (600) according to claim 10, further comprising using the granted radar resources subject to grant validity information transmitted by the radio network node (22), the grant validity information indicating one or more of a spatial constraint or a temporal constraint.

12. The method (600) according to any one of claims 1-11, further comprising, subsequent to being granted radar resources by the radio network node (22) in response to the radar request, terminating usage of the granted radar resources and transmitting an indication of the termination, for receipt by the radio network node (22).

13. A method (900) of operation by a radio network node (22) in a wireless communication network (10), wherein the radio network node (22) manages allocation of communication resources for utilization as radar resources, the method (900) comprising: carrying out (904) a random access (RA) procedure with a User Equipment (UE) (12), wherein the RA procedure comprises the radio network node (22) receiving a random access request from the UE (12), indicating that the UE (12) is requesting a grant of radar resources.

14. The method (900) according to claim 13, wherein the RA procedure further comprises sending a radar grant indication for the UE (12).

15. The method (900) according to claim 14, further comprising determining the radar grant indication in dependence on communication resource availability.

16. The method (900) according to claim 15, further comprising determining the communication resource availability according to a spatial reuse scheme, in which a same communication resource is reusable for radar operations in different beam directions used by the radio network node (22).

17. The method (900) according to any one of claims 13-16, further comprising allocating baseline resources (32), for utilization by UEs (12) as radar resources.

18. The method (900) according to claim 17, wherein the request for a grant of radar resources applies to communication resources (30) allocated as the baseline resources (32), and wherein the method (900) further comprises determining the communication resource availability with respect to the baseline resources (32).

19. The method (900) according to claim 17 or 18, wherein allocating the baseline resources (32) comprises allocating baseline resources (32) in different beam directions used by the radio network node (22), and wherein the method (900) further comprises transmitting System Information Blocks (SIBs) in the different beam directions used by the radio network node (22), with each SIB indicating the corresponding baseline resources (32).

20. The method (900) according to any one of claims 17-19, further comprising tracking utilization of communication resources (30) for radar on a per beam direction basis and adjusting the baseline resources (32) corresponding to each beam direction in dependence on the tracked utilization and communication needs associated with the beam direction.

21. The method (900) according to any one of claims 13-20, further comprising recognizing the random access request as being a request for radar resources based on the random access request using a communication resource designated for use by UEs (12) when performing random accesses for the purpose of requesting radar resources.

22. The method (900) according to any one of claims 13-21, wherein different random access preambles are mapped to different radar grant configurations or different radar characteristics, and wherein the method (900) further comprises determining a radar grant for the UE (12) according to which random access preamble was used by the UE (12).

23. The method (900) according to any one of claims 13-22, further comprising transmitting radar-related network configuration information indicating at least one of: baseline resources (32) allocated for radar usage; or one or more parameters to use when performing RA procedures to request grants of radar resources.

24. A user equipment (UE) (12) configured for operation in a wireless communication network (10) that allocates selected communication resources (30) of the wireless communication network (10) for utilization as radar resources, wherein the UE (12) comprises: communication interface circuitry (50); and processing circuitry (60) that is configured to request an allocation of radar resources from a radio network node (22) of the wireless communication network (10), wherein the processing circuitry (60) is configured particularly to: communicate a radar request to the radio network node (22) via the communication interface circuitry (50), via a random access (RA) procedure performed between the UE (12) and the radio network node (22).

25. The UE (12) of claim 24, wherein, with respect to communicating the radar request to the radio network node (22), the processing circuitry (60) is configured to request an allocation of radar resources, and receive a RA response indicating the allocation of radar resources.

26. The UE (12) according to claim 25, wherein the processing circuitry (60) is configured to request the allocation of radar resources responsive to determining that baseline resources (32) allocated for utilization as radar resources are unsuitable.

27. The UE (12) according to claim 26, wherein the processing circuitry (60) is configured to determine the unsuitability based on detecting interference at the UE (12) with respect to the baseline resources (32) or determining that the baseline resources (32) do not meet one or more requirements of radar operation by the UE (12).

28. The UE (12) according to claim 26 or 27, wherein, based on the UE (12) receiving radar- related network configuration information from the radio network node (22), the processing circuitry (60) is configured to perform at least one of identify the baseline resources (32) from the received radar-related network configuration information; or identify one or more parameters for performing the RA procedure from the received radar-related network configuration information.

29. The UE (12) according to any one of claims 24-28, wherein processing circuitry (60) is configured to perform the RA procedure as a two-step procedure in which the UE (12) communicates the radar request by transmitting a RA preamble designated for use in requesting radar resources, and wherein the RA procedure further comprises the UE r(12) eceiving a RA response from the radio network node (22) that comprises a radar grant indication.

30. The UE (12) according to any of claims 24-28, wherein the processing circuitry (60) is configured to perform the RA procedure as a four-step procedure in which the UE (12) communicates the radar request by transmitting a RA preamble designated for use in requesting radar resources, and wherein the RA procedure further comprises the UE (12) receiving a RA response from the radio network node (22) that indicates availability of radar resources, the UE (12) responding to the RA response by transmitting a message indicating radar request details, and the UE (12) subsequently receiving a message indicating grant details.

31. The UE (12) according to any one of claims 24-30, wherein the processing circuitry (60) is configured to indicate to the radio network node (22) that the RA procedure is for requesting radar resources by transmitting a RA request using a communication resource designated for performing random accesses for the purpose of requesting radar resources.

32. The UE (12) according to any one of claims 24-31, wherein one or more first random access preambles are designated for initiating connection to the wireless communication network (10), one or more second random access preambles are designated for requesting radar resources without initiating connection to the wireless communication network (10), and one or more third random access preambles are designated for jointly initiating connection to the wireless communication network (10) and requesting radar resources, and wherein the processing circuitry (60) is configured to choose either one of the one or more second random access preambles or one of the one or more third random access preambles for requesting radar resources, in dependence on whether connection to the wireless communication network (10) is needed by the UE (12).

33. The UE (12) according to any of claims 24-32, wherein, with respect to receiving an indication of granted radar resources from the radio network node (22) during the RA procedure, the processing circuitry (60) is configured to control the UE (12) to perform a radar operation using one or more of the granted radar resources.

34. The UE (12) according to claim 33, wherein the processing circuitry (60) is configured to control the UE (12) to use the granted radar resources subject to grant validity information transmitted by the radio network node (22), the grant validity information indicating one or more of a spatial constraint or a temporal constraint.

35. The UE (12) according to any one of claims 24-34, wherein with respect to the UE (12) being granted radar resources by the radio network node (22) in response to the radar request, the processing circuitry (60) is configured to terminate usage of the granted radar resources and transmit an indication of the termination, for receipt by the radio network node (12).

36. A radio network node (22) configured for operation in a wireless communication network (10), wherein the radio network node (22) manages allocation of communication resources (30) for utilization as radar resources, the radio network node (22) comprising: communication interface circuitry (90); and processing circuitry (100) configured to carry out a random access (RA) procedure with a User Equipment (UE) (12), wherein the RA procedure comprises the radio network node (22) receiving a random access request from the UE (12) via the communication interface circuitry (90), indicating that the UE (12) is requesting a grant of radar resources.

37. The radio network node (22) according to claim 36, wherein, for carrying out the RA procedure, the processing circuitry (100) is configured to send a radar grant indication for the UE (12).

38. The radio network node (22) according to claim 37, wherein the processing circuitry (100) is configured to determine the radar grant indication in dependence on communication resource availability.

39. The radio network node (22) according to claim 38, wherein the processing circuitry (100) is configured to determine the communication resource availability according to a spatial reuse scheme, in which a same communication resource is reusable for radar operations in different beam directions used by the radio network node (22).

40. The radio network node (22) according to any one of claims 36-39, wherein the processing circuitry (100) is configured to allocate baseline resources (32), for utilization by UEs (12) as radar resources.

41. The radio network node (22) according to claim 40, wherein the request for a grant of radar resources applies to communication resources (30) allocated as the baseline resources (32), and wherein the processing circuitry (100) is configured to determine the communication resource availability with respect to the baseline resources (32).

42. The radio network node (22) according to claim 40 or 41, wherein the processing circuitry (100) is configured to allocate corresponding baseline resources (32) in different beam directions used by the radio network node (22), and the processing circuitry (100) is configured to control the radio network node (22) to transmit System Information Blocks (SIBs) in the different beam directions used by the radio network node (22), with each SIB indicating the corresponding baseline resources (32).

43. The radio network node (22) according to any one of claims 40-42, wherein the processing circuitry (100) is configured to track utilization of communication resources (30) for radar on a per beam direction basis and adjust the baseline resources (32) corresponding to each beam direction in dependence on the tracked utilization and communication needs associated with the beam direction.

44. The radio network node (22) according to any one of claims 36-43, wherein the processing circuitry (90) is configured to recognize the random access request as being a request for radar resources based on the random access request using a communication resource (36) designated for use by UEs (12) when performing random accesses for the purpose of requesting radar resources.

45. The radio network node (22) according to any one of claims 36-44, wherein different random access preambles are mapped to different radar grant configurations or different radar characteristics, and wherein the processing circuitry (90) is configured to determine a radar grant for the UE (12) according to which random access preamble was used by the UE (12).

46. The radio network node (22) according to any one of claims 36-45, wherein the processing circuitry (100) is configured to transmit, via the communication interface circuitry (90), radar-related network configuration information indicating at least one of: baseline resources (32) allocated for radar usage; or one or more parameters to use when performing RA procedures to request grants of radar resources.