Reference signal transmission for sensing and communication system

Abstract

Disclosed are methods, apparatuses, and systems for sending messages. One of the methods includes: transmitting one or more first reference signals; receiving, from a second node, at least one of: a request to transmit one or more second reference signals, one or more measurements on the one or more first reference signals, one or more measurements on one or more reflected first reference signals received by the second node, or a first sensing result of sensing one or more objects, wherein the one or more reflected first reference signals are formed by reflection of the one or more first reference signals from the one or more objects; and obtaining a decision on whether to transmit the one or more second reference signals.

Description

REFERENCE SIGNAL TRANSMISSION FOR SENSING AND COMMUNICATION SYSTEMCROSS-REFERENCE TO RELATED PATENT APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 554,830, filed on February 16, 2024, entitled “REFERENCE SIGNAL TRANSMISSION FOR SENSING AND COMMUNICATION SYSTEM,” the entirety of which is incorporated by reference herein.

[0002] Apparatuses and methods consistent with the present disclosure relate generally to communications, more specifically, methods, systems, and devices for adaptive reference signal transmission in integrated sensing and communication systems.

[0003] Integrated sensing and communication (ISAC) is a crucial technology in contemporary telecommunication services, for example, in autonomous driving. In ISAC, objects are sensed through the utilization of existing reference signals, such as positioning reference signals. Based on the sensing, various characteristics of the objects, such as their position, velocity, and acceleration, can be estimated. One drawback of this approach to reusing existing reference signals is that the sensing accuracy may not be sufficient, as these signals are not optimized for sensing purposes. To address this issue, the objects can be sensed using ISAC reference signals specifically designed for this purpose. However, this approach presents a challenge, as the continuous use of ISAC reference signals for sensing can lead to substantial consumption of wireless resources and may lack spectral efficiency. Systems and methods that enhance sensing accuracy by dynamically adjusting reference signal parameters and transmitting ISAC reference signals when necessary, while also improving spectral efficiency by suppressing the transmission of these signals when unnecessary, are desired.

[0004] According to some embodiments of the present disclosure, there is provided a method for a node for a communication. The method includes: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; obtaining a decision on whether to transmit one or more second reference signals, the decision being made based on the first sensing result; and transmitting the one or more second reference signals, based on the decision.

[0005] According to some embodiments of the present disclosure, there is provided a method for a first node for a communication. The method includes: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; and transmitting, to a second node, at least one of: a request to transmit one or more second reference signals to the one or more objects, the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0006] According to some embodiments of the present disclosure, there is provided a method for a second node for a communication. The method includes: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; and transmitting, to a second node, at least one of: a request to transmit one or more second reference signals to the one or more objects, the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0007] According to some embodiments of the present disclosure, there is provided a method for a second node for a communication. The method includes: receiving, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by reflection of one or more first reference signals from one or more objects, or a first sensing result of sensing the one or more objects based on processing of the one or more measurements; obtaining a decision on whether to transmit the one or more second reference signals to the one or more objects; transmitting the one or more second reference signals, based on the decision; receiving, from the one or more objects, one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected second reference signals.

[0008] According to some embodiments of the present disclosure, there is provided a method for a first node for a communication. The method includes: transmitting one or more first reference signals; receiving, from a second node, at least one of: a request to transmit one or more second reference signals, one or more measurements on the one or more first reference signals, one or more measurements on one or more reflected first reference signals received by the second node, or a first sensing result of sensing one or more objects, wherein the one or more reflected first reference signals are formed by reflection of the one or more first reference signals from the one or more objects; and obtaining a decision on whether to transmit the one or more second reference signals.

[0009] According to some embodiments of the present disclosure, there is provided a method for a second node for a communication. The method includes: receiving at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals received by the second node, or one or more measurements on the one or more reflected first reference signals received by the second node; and transmitting, to the first node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or a first sensing result, for a determination of a decision on whether the one or more second reference signals need to be transmitted from the first node.

[0010] According to some embodiments of the present disclosure, there is provided a method for a first node for a communication. The method includes: transmitting one or more first reference signals; receiving at least one of: one or more second reference signals transmitted from a second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from one or more objects; and obtaining a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals, wherein the one or more second reference signals are transmitted from the second node based on a decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0011] According to some embodiments of the present disclosure, there is provided a method for a second node for a communication. The method includes: receiving at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals, or one or more measurements on the one or more reflected first reference signals; obtaining a decision on whether to transmit one or more second reference signals; and transmitting the one or more second reference signals, based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0012] According to some embodiments of the present disclosure, there is provided a method for a second node for a communication. The method includes: receiving at least one of: one or more reference signals transmitted from a first node, or one or more reflected reference signals formed by reflection of the one or more reference signals from one or more objects; and obtaining a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more reference signals, or one or more measurements on the one or more reflected reference signals, wherein the one or more reference signals are transmitted from a first node based on a decision indicating that the one or more reference signals need to be transmitted from the first node.

[0013] According to some embodiments of the present disclosure, there is provided a method for a first node for a communication. The method includes: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; transmitting, to a second node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result; receiving at least one of: one or more second reference signals transmitted from the second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals.

[0014] According to some embodiments of the present disclosure, there is provided a method for a second node for a communication. The method includes: receiving, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by one or more first reference signal transmitted from the first node and reflected from the one or more objects, or a first sensing result obtained based on the one or more measurements; obtaining a decision on whether to transmit the one or more second reference signals; and transmitting the one or more second reference signals based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0015] According to some embodiments of the present disclosure, there is provided a node for a communication. The node includes a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: transmit one or more first reference signals; receive, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtain a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; obtain a decision on whether to transmit one or more second reference signals, the decision being made based on the first sensing result; and transmit the one or more second reference signals, based on the decision.

[0016] According to some embodiments of the present disclosure, there is provided a first node for a communication. The first node includes a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: transmit one or more first reference signals; receive, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtain a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; and transmit, to a second node, at least one of: a request to transmit one or more second reference signals to the one or more objects, the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0017] According to some embodiments of the present disclosure, there is provided a second node for a communication. The second node includes a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: receive, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by reflection of one or more first reference signals from one or more objects, or a first sensing result of sensing the one or more objects based on processing of the one or more measurements; obtain a decision on whether to transmit the one or more second reference signals to the one or more objects; transmit the one or more second reference signals, based on the decision; receive, from the one or more objects, one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtain a second sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected second reference signals.

[0018] According to some embodiments of the present disclosure, there is provided a first node for a communication. The first node includes a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: transmit one or more first reference signals; receive, from a second node, at least one of: a request to transmit one or more second reference signals, one or more measurements on the one or more first reference signals, one or more measurements on one or more reflected first reference signals received by the second node, or a first sensing result of sensing one or more objects, wherein the one or more reflected first reference signals are formed by reflection of the one or more first reference signals from the one or more objects; and obtain a decision on whether to transmit the one or more second reference signals.

[0019] According to some embodiments of the present disclosure, there is provided a second node for a communication. The second node includes a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: receive at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtain a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals received by the second node, or one or more measurements on the one or more reflected first reference signals received by the second node; and transmit, to the first node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or a first sensing result, for a determination of a decision on whether the one or more second reference signals need to be transmitted from the first node.

[0020] According to some embodiments of the present disclosure, there is provided a first node for a communication. The first node includes a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: transmit one or more first reference signals; receive at least one of: one or more second reference signals transmitted from a second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from one or more objects; and obtain a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals, wherein the one or more second reference signals are transmitted from the second node based on a decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0021] According to some embodiments of the present disclosure, there is provided a second node for a communication. The second node includes a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: receive at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtain a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals, or one or more measurements on the one or more reflected first reference signals; obtain a decision on whether to transmit one or more second reference signals; and transmit the one or more second reference signals, based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0022] According to some embodiments of the present disclosure, there is provided a second node for a communication. The second node includes a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: receive at least one of: one or more reference signals transmitted from a first node, or one or more reflected reference signals formed by reflection of the one or more reference signals from one or more objects; and obtain a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more reference signals, or one or more measurements on the one or more reflected reference signals, wherein the one or more reference signals are transmitted from a first node based on a decision indicating that the one or more reference signals need to be transmitted from the first node.

[0023] According to some embodiments of the present disclosure, there is provided a first node for a communication. The first node includes a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: transmit one or more first reference signals; receive, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtain a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; transmit, to a second node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result; receive at least one of: one or more second reference signals transmitted from the second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtain a second sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals.

[0024] According to some embodiments of the present disclosure, there is provided a second node for a communication. The second node includes a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: receive, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by one or more first reference signal transmitted from the first node and reflected from the one or more objects, or a first sensing result obtained based on the one or more measurements; obtain a decision on whether to transmit the one or more second reference signals; and transmit the one or more second reference signals based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0025] According to some embodiments of the present disclosure, there is provided a non-transitory computer-readable medium storing instructions that are executable by one or more processors of a node for a communication, to perform a method. The method includes: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; obtaining a decision on whether to transmit one or more second reference signals, the decision being made based on the first sensing result; and transmitting the one or more second reference signals, based on the decision.

[0026] According to some embodiments of the present disclosure, there is provided a non-transitory computer-readable medium storing instructions that are executable by one or more processors of a first node for a communication, to perform a method. The method includes: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; and transmitting, to a second node, at least one of: a request to transmit one or more second reference signals to the one or more objects, the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0027] According to some embodiments of the present disclosure, there is provided a non-transitory computer-readable medium storing instructions that are executable by one or more processors of a second node for a communication, to perform a method. The method includes: receiving, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by reflection of one or more first reference signals from one or more objects, or a first sensing result of sensing the one or more objects based on processing of the one or more measurements; obtaining a decision on whether to transmit the one or more second reference signals to the one or more objects; transmitting the one or more second reference signals, based on the decision; receiving, from the one or more objects, one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected second reference signals.

[0028] According to some embodiments of the present disclosure, there is provided a non-transitory computer-readable medium storing instructions that are executable by one or more processors of a first node for a communication, to perform a method. The method includes: transmitting one or more first reference signals; receiving, from a second node, at least one of: a request to transmit one or more second reference signals, one or more measurements on the one or more first reference signals, one or more measurements on one or more reflected first reference signals received by the second node, or a first sensing result of sensing one or more objects, wherein the one or more reflected first reference signals are formed by reflection of the one or more first reference signals from the one or more objects; and obtaining a decision on whether to transmit the one or more second reference signals.

[0029] According to some embodiments of the present disclosure, there is provided a non-transitory computer-readable medium storing instructions that are executable by one or more processors of a second node for a communication, to perform a method. The method includes: receiving at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals received by the second node, or one or more measurements on the one or more reflected first reference signals received by the second node; and transmitting, to the first node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or a first sensing result, for a determination of a decision on whether the one or more second reference signals need to be transmitted from the first node.

[0030] According to some embodiments of the present disclosure, there is provided a non-transitory computer-readable medium storing instructions that are executable by one or more processors of a first node for a communication, to perform a method. The method includes: transmitting one or more first reference signals; receiving at least one of: one or more second reference signals transmitted from a second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from one or more objects; and obtaining a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals, wherein the one or more second reference signals are transmitted from the second node based on a decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0031] According to some embodiments of the present disclosure, there is provided a non-transitory computer-readable medium storing instructions that are executable by one or more processors of a second node for a communication, to perform a method. The method includes: receiving at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals, or one or more measurements on the one or more reflected first reference signals; obtaining a decision on whether to transmit one or more second reference signals; and transmitting the one or more second reference signals, based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0032] According to some embodiments of the present disclosure, there is provided a non-transitory computer-readable medium storing instructions that are executable by one or more processors of a second node for a communication, to perform a method. The method includes: receiving at least one of: one or more reference signals transmitted from a first node, or one or more reflected reference signals formed by reflection of the one or more reference signals from one or more objects; and obtaining a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more reference signals, or one or more measurements on the one or more reflected reference signals, wherein the one or more reference signals are transmitted from a first node based on a decision indicating that the one or more reference signals need to be transmitted from the first node.

[0033] According to some embodiments of the present disclosure, there is provided a non-transitory computer-readable medium storing instructions that are executable by one or more processors of a first node for a communication, to perform a method. The method includes: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; transmitting, to a second node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result; receiving at least one of: one or more second reference signals transmitted from the second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals.

[0034] According to some embodiments of the present disclosure, there is provided a non-transitory computer-readable medium storing instructions that are executable by one or more processors of a second node for a communication, to perform a method. The method includes: receiving, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by one or more first reference signal transmitted from the first node and reflected from the one or more objects, or a first sensing result obtained based on the one or more measurements; obtaining a decision on whether to transmit the one or more second reference signals; and transmitting the one or more second reference signals based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0035] FIG. 1 is a schematic diagram illustrating mono-static sensing, consistent with some embodiments of the present disclosure.

[0036] FIG. 2 is a schematic diagram illustrating bi-static sensing, consistent with some embodiments of the present disclosure.

[0037] FIG. 3A is a schematic diagram illustrating first mode of six exemplary sensing modes, consistent with some embodiments of the present disclosure.

[0038] FIG. 3B is a schematic diagram illustrating second mode of six exemplary sensing modes, consistent with some embodiments of the present disclosure.

[0039] FIG. 3C is a schematic diagram illustrating third mode of six exemplary sensing modes, consistent with some embodiments of the present disclosure.

[0040] FIG. 3D is a schematic diagram illustrating fourth mode of six exemplary sensing modes, consistent with some embodiments of the present disclosure.

[0041] FIG. 3E is a schematic diagram illustrating fifth mode of six exemplary sensing modes, consistent with some embodiments of the present disclosure.

[0042] FIG. 3F is a schematic diagram illustrating sixth mode of six exemplary sensing modes, consistent with some embodiments of the present disclosure.

[0043] FIG. 4 is a schematic diagram illustrating an exemplary time-frequency domain resource for a positioning reference signal (PRS) for integrated sensing and communication (ISAC) in the art.

[0044] FIG. 5 is a schematic diagram illustrating an exemplary time-frequency domain resource for a joint PRS, channel state information reference signal (CSI-RS), and demodulation reference signal (DMRS) for ISAC in the art.

[0045] FIG. 6 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure.

[0046] FIG. 7 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure.

[0047] FIG. 8 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure.

[0048] FIG. 9 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure.

[0049] FIG. 10 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure.

[0050] FIG. 11 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure.

[0051] FIG. 12 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure.

[0052] FIG. 13 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure.

[0053] FIG. 14 is a flow chart illustrating a method for a node for a communication, consistent with some embodiments of the present disclosure.

[0054] FIG. 15 is a flow chart illustrating a method for a first node for a communication, consistent with some embodiments of the present disclosure.

[0055] FIG. 16 is a flow chart illustrating a method for a second node for a communication, consistent with some embodiments of the present disclosure.

[0056] FIG. 17 is a flow chart illustrating a method for a first node for a communication, consistent with some embodiments of the present disclosure.

[0057] FIG. 18 is a flow chart illustrating a method for a second node for a communication, consistent with some embodiments of the present disclosure.

[0058] FIG. 19 is a flow chart illustrating a method for a first node for a communication, consistent with some embodiments of the present disclosure.

[0059] FIG. 20 is a flow chart illustrating a method for a second node for a communication, consistent with some embodiments of the present disclosure.

[0060] FIG. 21 is a flow chart illustrating a method for a second node for a communication, consistent with some embodiments of the present disclosure.

[0061] FIG. 22 is a flow chart illustrating a method for a first node for a communication, consistent with some embodiments of the present disclosure.

[0062] FIG. 23 is a flow chart illustrating a method for a second node for a communication, consistent with some embodiments of the present disclosure.

[0063] FIG. 24 is a block diagram of a node for a communication, consistent with some embodiments of the present disclosure.

[0064] Reference will now be made in detail to exemplary embodiments, examples of which are illustrated in the accompanying drawings. The following description refers to the accompanying drawings in which the same numbers in different drawings represent the same or similar elements unless otherwise represented. The implementations set forth in the following description of exemplary embodiments do not represent all implementations consistent with the present disclosure. Instead, they are merely examples of systems, apparatuses, and methods consistent with aspects related to the present disclosure as recited in the appended claims.

[0065] In the present disclosure, the term “integrated sensing and communication (ISAC)” generally refers, but is not limited to, sensing capabilities being provided by the same wireless communication system and infrastructure as used for communication.

[0066] The use cases and service requirements of ISAC described in this disclosure are consistent with those of the 3rd Generation Partnership Project (3GPP) standard. For example, the possible use cases for ISAC described in this disclosure may include, but are not limited to, object detection and tracking (e.g., vehicle, unmanned aerial vehicle (UAV), human, animal), environment monitoring (e.g., rainfall, flooding), and motion monitoring (e.g., sleep monitoring, hand gesture recognition), in outdoor and indoor scenarios. The performance requirements for each service category of the above use cases may include the requirements as shown in Table 1 of TS 22.137.

[0067] In the present disclosure, the term “node” is used as a general term that includes, but is not limited to, user equipment (UE), one or more vehicles, one or more vehicle mounted modules, and one or more network infrastructure nodes such as base stations, core networks, roadside units, repeaters, transponders, wireless routers, controllers, access points, and sub-systems thereof. In this disclosure, the terms “radio access network”, “core network”, and “network” are used as general terms which include, but are not limited to, terrestrial and non-terrestrial (e.g., satellite) systems.

[0068] FIG. 1 is a schematic diagram illustrating mono-static sensing scheme, consistent with some embodiments of the present disclosure. The term “mono-static sensing” described in this disclosure is consistent with the definition of the term in the 3GPP specifications. Referring to FIG. 1, a system 100 includes a sensing transmitter 102, a sensing receiver 104, a processing system 106, and a sensing service 108. In some embodiments, the system 100 may be a node. As shown in FIG. 1, in a mono-static sensing scheme, the sensing transmitter 102 and the sensing receiver 104 are co-located in the same system 100. For example, in some embodiments, the sensing transmitter 102 and the sensing receiver 104 may be attached to each other or separated from each other within the same node. The sensing transmitter 102 transmits a reference signal 116 to an object 112, and a reference signal 118 to an object 114. The term “signal” described in the present disclosure may refer to “one or more signals”, “data”, or “one or more data packets”. The reference signal 116 is reflected from the object 112 and transmitted as a reflected signal 120 and the reflected signal 120 is received by the sensing receiver 104. Similarly, the references signal 118 is reflected from the object 114 and transmitted as a reflected signal 122, and the reflected signal 122 is received by the sensing receiver 104. The reflected signals 120 and the 122 may be non-line-of-sight (NLOS) signals. In the present disclosure, the term “reflection” (or “reflected”) may include a passive reflection of electromagnetic waves on a surface of an object, or an active reflection of the electromagnetic waves by the object, for example, by transmission of corresponding reflection signals. The term “reflection” (or “reflected”) may also include scattering of (or scattered) electromagnetic waves by the object.

[0069] The sensing receiver 104 may provide the sensing data to the processing system 106 for processing. The processing system 106 may include one or more processors or processing circuitry that processes the signals received from the sensing receiver 104 and obtains sensing results. For example, the processing system 106 may extract and analyze the OFDM patterns, delay of arrival, angle-of-arrival, and Doppler of the received signals. Based on the information of the received reference signals, the processing system 106 may further perform computation to determine characteristics (e.g., position, velocity, acceleration, angle, shape, etc.) of the objects 112 and 114. In some embodiments, the sensing receiver 104 may extract the information of the received reference signals and provide the information to the processing system 106. The processing system 106 then may provide the sensing results to the sensing service 108. The sensing service may have a list of external parties to which the sensing data need to be distributed or may accept requests from the external parties for the sensing data. For example, as shown in FIG. 1, the sensing service 108 sends the sensing data to a trusted third party 110. The sensing service 108 may be hardware, software, or combination of hardware and software. In some embodiments, the sensing transmitter 102 may include a plurality of sensing transmitters and / or the sensing receiver 104 may include a plurality of sensing receivers.

[0070] FIG. 2 is a schematic diagram illustrating bi-static sensing scheme, consistent with some embodiments of the present disclosure. The term “bi-static sensing” described in this disclosure is consistent with the definition of the term in the 3GPP specifications. Referring to FIG. 2, a system 200 includes a sensing transmitter 202, a sensing receiver 204, a processing system 206, and a sensing service 208. As shown in FIG. 2, in a bi-static sensing scheme, the sensing transmitter 202 and the sensing receiver 204 are disposed at different places. For example, in some embodiments, the sensing transmitter 202 is disposed in a first node, and the sensing receiver 204 is disposed in a second node. The sensing transmitter 202 transmits a reference signal 216 to an object 212, and a reference signal 218 to an object 214. The reference signal 216 is reflected from the object 212 and transmitted as a reflected signal 220 and the reflected signal 220 is received by the sensing receiver 204. Similarly, the references signal 218 is reflected from the object 214 and transmitted as a reflected signal 222, and the reflected signal 222 is received by the sensing receiver 204. The reflected signals 220 and the 222 may be NLOS signals. The sensing receiver 204 may also receive the signal transmitted directly from the sensing transmitter 202, although it is not shown in FIG. 2. The signals transmitted directly from the sensing transmitter 202 may be line-of-sight (LOS) signals.

[0071] The sensing receiver 204 may provide the sensing signals to the processing system 206 for processing. The processing system 206 may include one or more processors or processing circuitry that processes the signals received from the sensing receiver 204 and obtains sensing results. For example, the processing system 206 may extract and analyze the OFDM patterns, delay of arrival, angle-of-arrival, and Doppler of the received signals. Based on the information of the received reference signals, the processing system 206 may further perform computation to determine characteristics (e.g., position, velocity, acceleration, angle, shape, etc.) of the objects 212 and 214. In some embodiments, the sensing receiver 204 may extract the information of the received reference signals and provide the information to the processing system 206. The processing system 206 then may provide the sensing results to the sensing service 208. The sensing service may have a list of external parties to which the sensing data need to be distributed or may accept requests from the external parties for the sensing data. For example, as shown in FIG. 2, the sensing service 208 sends the sensing data to a trusted third party 210. The sensing service 208 may be hardware, software, or combination of hardware and software. In some embodiments, the sensing receiver 204, the processing system 206, and the sensing service 208 are disposed in the same node. In some embodiments, the sensing transmitter 202 may include a plurality of sensing transmitters and / or the sensing receiver 204 may include a plurality of sensing receivers.

[0072] FIG. 3A-3F are schematic diagrams illustrating six exemplary sensing modes, consistent with some embodiments of the present disclosure. In some embodiments, for integrated sensing and communication (ISAC), any of the six different sensing modes as illustrated in FIG. 3A-3F may be used. FIG. 3A illustrates a mono-static sensing mode in which a node 302 (e.g., a base station) includes both a sensing transmitter (not shown) and a sensing receiver (not shown). The sensing transmitter may be similar to the sensing transmitter 102 of FIG. 1, and the sensing receiver may be similar to the sensing receiver 104 of FIG. 1. For the sake of simplicity, the descriptions of the sensing transmitter and the sensing receiver are omitted here. The node 302 may be any base station currently existing, such as base stations for long term evolution (LTE) or new radio (NR), or base stations for a future generation (6thgeneration (6G), 7thgeneration (7G), or any other future generation) radio access technology (RAT). The node 302 transmits a signal to an object 304 and receives a reflected signal from the object 302. The node 302 may also include a processing system (not shown), such as the processing system 106 of FIG. 1, a sensing service (not shown), such as the sensing service 108 of FIG. 1, to process the received sensing data, obtain the characteristic information (e.g., position, velocity, acceleration, etc.) of the object 304, and provide the information of the object 304 to one or more parties.

[0073] FIG. 3B illustrates a mono-static sensing mode in which a node 306 (e.g., a UE) includes both a sensing transmitter (not shown) and a sensing receiver (not shown). The sensing transmitter may be similar to the sensing transmitter 102 of FIG. 1, and the sensing receiver may be similar to the sensing receiver 104 of FIG. 1. For the sake of simplicity, the descriptions of the sensing transmitter and the sensing receiver are omitted here. The node 306 may be any type of UE, for example, a portable device, a computer, a vehicle, or a component of vehicle, etc. The node 306 transmits a signal to an object 308 and receives a reflected signal from the object 308. The node 306 may also include a processing system (not shown), such as the processing system 106 of FIG. 1, a sensing service (not shown), such as the sensing service 108 of FIG. 1, to process the received sensing data, obtain the characteristic information (e.g., position, speed, acceleration, etc.) of the object 308, and provide the information of the object 308 to one or more parties.

[0074] FIG. 3C illustrates a bi-static sensing mode in which a node 310 (e.g., a base station) includes a sensing transmitter (not shown) and a node 312 (e.g., another base station) includes a sensing receiver (not shown). The sensing transmitter may be similar to the sensing transmitter 202 of FIG. 2, and the sensing receiver may be similar to the sensing receiver 204 of FIG. 2. For the sake of simplicity, the descriptions of the sensing transmitter and the sensing receiver are omitted here. The node 310 and the node 312 may be any base station (e.g., gNB) for any RAT, for example, 4G, 5G, and any future generation RAT. The node 310 and the node 312 may be two base stations for the same RAT or different RATs. The node 310 transmits a signal to an object 314 and the node 312 receives a reflected signal from the object 314. In some embodiments, the node 312 may also receive LOS signals transmitted from the node 310. The node 312 may also include a processing system (not shown), such as the processing system 206 of FIG. 2, a sensing service (not shown), such as the sensing service 208 of FIG. 2, to process the received sensing data, obtain the characteristic information (e.g., position, velocity, acceleration, etc.) of the object 314, and provide the information of the object 314 to one or more parties.

[0075] FIG. 3D illustrates a bi-static sensing mode in which a node 316 (e.g., a UE) includes a sensing transmitter (not shown) and a node 318 (e.g., another UE) includes a sensing receiver (not shown). The sensing transmitter may be similar to the sensing transmitter 202 of FIG. 2, and the sensing receiver may be similar to the sensing receiver 204 of FIG. 2. For the sake of simplicity, the descriptions of the sensing transmitter and the sensing receiver are omitted here. The node 316 and the node 318 may be any type of UE, for example, a portable device, a computer, a vehicle, or a component of vehicle, etc. The node 316 and the node 318 may be the same type of UE or different types of UE. In some embodiments, the node 316 and the node 318 may communicate with other using sidelink communications, for example, via PC5 interface. The node 310 transmits a signal to an object 320 and the node 312 receives a reflected signal from the object 320. In some embodiments, the node 318 may also receive LOS signals transmitted from the node 316. The node 318 may also include a processing system (not shown), such as the processing system 206 of FIG. 2, a sensing service (not shown), such as the sensing service 208 of FIG. 2, to process the received sensing data, obtain the characteristic information (e.g., position, speed, acceleration, etc.) of the object 320, and provide the information of the object 320 to one or more parties.

[0076] FIG. 3E illustrates a bi-static sensing mode in which a node 322 (e.g., a base station) includes a sensing transmitter (not shown) and a node 324 (e.g., a UE) includes a sensing receiver (not shown). The sensing transmitter may be similar to the sensing transmitter 202 of FIG. 2, and the sensing receiver may be similar to the sensing receiver 204 of FIG. 2. For the sake of simplicity, the descriptions of the sensing transmitter and the sensing receiver are omitted here. The node 322 may be any base station (e.g., gNB) for any RAT, for example, 4G, 5G, and any future generation RAT. The node 324 may be any type of UE, for example, a portable device, a computer, a vehicle, or a component of vehicle, etc. In some embodiments, the node 322 and the node 324 may communicate with each other via Uu interface. The node 322 transmits a signal to an object 326 and the node 324 receives a reflected signal from the object 326. In some embodiments, the node 324 may also receive LOS signals transmitted from the node 322. The node 324 may also include a processing system (not shown), such as the processing system 206 of FIG. 2, a sensing service (not shown), such as the sensing service 208 of FIG. 2, to process the received sensing data, obtain the characteristic information (e.g., position, velocity, acceleration, etc.) of the object 326, and provide the information of the object 326 to one or more parties.

[0077] FIG. 3F illustrates a bi-static sensing mode in which a node 328 (e.g., a UE) includes a sensing transmitter (not shown) and a node 330 (e.g., a base station) includes a sensing receiver (not shown). The sensing transmitter may be similar to the sensing transmitter 202 of FIG. 2, and the sensing receiver may be similar to the sensing receiver 204 of FIG. 2. For the sake of simplicity, the descriptions of the sensing transmitter and the sensing receiver are omitted here. The node 328 may be any type of UE, for example, a portable device, a computer, a vehicle, or a component of vehicle, etc. The node 330 may be any base station (e.g., gNB) for any RAT, for example, 4G, 5G, and any future generation RAT. In some embodiments, the node 328 and the node 330 may communicate with each other via Uu interface. The node 328 transmits a signal to an object 332 and the node 330 receives a reflected signal from the object 332. In some embodiments, the node 330 may also receive LOS signals transmitted from the node 328. The node 330 may also include a processing system (not shown), such as the processing system 206 of FIG. 2, a sensing service (not shown), such as the sensing service 208 of FIG. 2, to process the received sensing data, obtain the characteristic information (e.g., position, velocity, acceleration, etc.) of the object 332, and provide the information of the object 332 to one or more parties.

[0078] Although the disclosed methods are exemplified with terrestrial mobile communication systems, such as 3GPP long term evolution (LTE) and / or NR / 5G radio access technology, the scope of the present disclosure is not so limited. The methods of the present disclosure can be applied to any communication systems, including non-terrestrial communication systems, that make use of one or more nodes or entities.

[0079] In some embodiments, the objects described with respect to FIGs. 1, 2, 3A-3F may be sensed by using reference signals for uplink, downlink, and / or sidelink communications. The examples of the reference signals include, but are not limited to, positioning reference signal (PRS), channel state information reference signal (CSI-RS), sounding reference signal (SRS), demodulation reference signal (DMRS), synchronization signal (SS), and phase tracking reference signal (PT-RS).

[0080] FIG. 4 is a schematic diagram illustrating an exemplary time-frequency domain resource for a PRS in the art. Referring to FIG. 4, in time domain, the PRS may include multiple time slots. FIG. 4 shows one time slot in time domain, which includes 14 orthogonal frequency division multiplexing (OFDM) symbols. In frequency domain, the PRS includes multiple subcarriers, for example, 12 subcarriers as shown in FIG. 4.

[0081] FIG. 5 is a schematic diagram illustrating an exemplary time-frequency domain resource for a joint PRS, CSI-RS, and DMRS in the art. Referring to FIG. 5, in time domain, the joint PRS, CSI-RS, and DMRS may include multiple time slots. FIG. 5 shows one time slot in time domain, which includes 14 OFDM symbols. The PRS includes OFDM symbols 1-5 and 7-12, the DMRS includes OFDM symbols 2, 4, 8, and 10, and the CSI-RS includes OFDM symbol 6. In frequency domain, the joint PRS, CSI-RS, and DMRS includes multiple subcarriers, for example, 12 subcarriers as shown in FIG. 5. The right-hand side drawing of FIG. 5 shows a continuous pattern of the time-frequency domain resource corresponding to the subcarriers 1, 3, 5, 7, 9, and 11, and the OFDM symbols 1-11. The joint PRS, CSI-RS, and DMRS may be used for analysis of the range and velocity estimation of objects. However, an issue of using the existing reference signal(s) is that the sensing accuracy may not be sufficient because the existing reference signals are not optimized for sensing.

[0082] To address the above noted issue, in some embodiments, the objects may be sensed by using ISAC reference signal(s), which is designed for ISAC. For example, one candidate of ISAC reference signal(s) may be based on orthogonal frequency division multiplexing (OFDM) waveform with denser reference symbols (e.g., in time and / or frequency domains) and / or with different reference symbol mapping (e.g., in time and / or frequency domains). Another candidate of ISAC reference signal(s) may be based on non-OFDM waveform. The examples of the non-OFDM waveform may include frequency modulated continuous wave (FMCW) waveform and code-division multiple access (CDMA) waveform, which have been traditionally used for radar sensing. However, such an approach also has an issue because continuously using ISAC reference signal(s) for sensing may consume a significant number of wireless resources and may not be spectrally efficient.

[0083] At least some embodiments of the present disclosure provide solutions to the above-described issues. For example, in some embodiments, a seven-step procedure that may provide improved sensing accuracy is adopted. In a step 1, a node A transmits first reference signal(s). The first reference signal(s) may be, for example, at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, or PRS. In a step 2, the node A and / or a node B receives reflected first reference signal(s) that are formed by reflection of the first reference signal(s) by surrounding object(s). In a step 3, the node A and / or the node B obtains a first sensing result by processing the received first reference signal(s) to sense the surrounding object(s). In a step 4, based on the first sensing result in the step 3, the node A and / or the node B obtains a decision on whether to transmit second reference signal(s) to improve the sensing accuracy. The second reference signal may be, for example, ISAC signals. In a step 5, based on the decision to transmit the second reference signal(s) in a step 4, the node A and / or the node B transmits the second reference signal(s), where one or more parameter values of the second reference signal(s) may be adapted based on the first sensing result. The one or more parameters may include, but are not limited to, carrier frequency, bandwidth, waveform, beam width, beam direction, and transmission power. In a step 6, the node A and / or the node B receives the second reference signal(s) reflected by the surrounding object(s). In a step 7, the node A and / or the node B obtains a second sensing result by processing the received first reference signal(s) with or without combining it with the received first reference signal(s) and / or the first sensing result to sense the surrounding object(s).

[0084] Based on the above-noted seven-step procedure, in some embodiments, one or more of four different cases (case A, case B, case C, and case D) are adopted. Case A is directed to a mono-static sensing followed by another mono-static sensing. In a first sub-case (case A-1), the sensing in the above-noted steps 1-7 is mono-static sensing with the node A as a transmitter and a receiver. In a second sub-case (case A-2), the sensing in the above-noted steps 1-3 is mono-static sensing with the node A as a transmitter and a receiver, and the sensing in the above-noted steps 5-7 is mono-static sensing with the node B as a transmitter and a receiver.

[0085] Case B is directed to a bi-static sensing followed by another bi-static sensing. In a first sub-case (case B-1), the sensing in the above-noted steps 1-7 is a bi-static sensing with the node A as a transmitter and the node B as a receiver. In a second sub-case (case B-2), the sensing in the above-noted steps 1-3 is a bi-static sensing with the node A as a transmitter and the node B as a receiver, and the sensing in the above-noted steps 5-7 is a bi-static sensing with the node A as a receiver and the node B as a transmitter.

[0086] Case C is directed to a mono-static sensing followed by a bi-static sensing. In first sub-case (case C-1), the sensing in the above-noted steps 1-3 is a mono-static sensing with the node A as a transmitter and a receiver, and the sensing in the above-noted steps 5-7 is a bi-static sensing with the node A as a transmitter and the node B as a receiver. In a second sub-case (case C-2), the sensing in the above-noted steps 1-3 is a mono-static sensing with the node A as a transmitter and a receiver, and the sensing in the above-noted steps 5-7 is a bi-static sensing with the node A as a receiver and the node B as a transmitter.

[0087] Case D is directed to a bi-static sensing followed by a mono-static sensing. In a first sub-case (case D-1), the sensing in the above-noted steps 1-3 is a bi-static sensing with the node A as a transmitter and the node B as a receiver, and the sensing in the above-noted steps 5-7 is a mono-static sensing with the node A as a transmitter and a receiver. In a second sub-case (case D-2), the sensing in the above-noted steps 1-3 is a bi-static sensing with the node A as a transmitter and the node B as a receiver, and the sensing in the above-noted steps 5-7 is a mono-static sensing with the node B as a transmitter and a receiver.

[0088] At least some embodiments of the present disclosure provide advantages, such as enhanced sensing accuracy achieved by transmitting ISAC reference signal(s) when necessary and by adjusting their parameter values. Additionally, there is improved spectral efficiency through the suppression of ISAC reference signal transmissions when they are not required. The above-noted cases are further illustrated as example sequence diagrams in FIGs. 6-13 described below.

[0089] The methods and apparatuses for adaptive reference signal transmission for ISAC described in the present disclosure are exemplified with 3GPP NR radio access technology. However, the scope of the present disclosure is not so limited. In some embodiments, the methods and apparatuses can be applied to any wireless communication system that makes use of ISAC. For example, in some embodiments, the methods may be used with 3GPP 4G technology or future 3GPP radio technology generations such as 6G. In some embodiments, the disclosed methods may be used for non-3GPP technologies, for example, IEEE and its 802.11 variants, Wi-Fi, WiMAX, etc.

[0090] FIG. 6 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure. Referring to FIG. 6, a node A may be a node capable of mono-static sensing. For example, the node A may include a sensing transmitter, such as the sensing transmitter 102 of FIG. 1, and a sensing receiver, such as the sensing receiver 104 of FIG. 1. At a step 602, the node A transmits one or more first reference signals. The one or more first reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). At a step 604, the one or more first reference signals are reflected from one or more objects. The one or more objects may be any objects surrounding the node A. The one or more first reference signals may be passively reflected by the surface of the one or more objects, or actively reflected by the one or more objects. At a step 606, the node A receives the one or more reflected first reference signals. At a step 608, the node A obtains a first sensing result based on processing of the one or more reflected first reference signals to sense the one or more objects. In some embodiments, the node A may obtain the first sensing result by itself by processing the one or more reflected first reference signals. In some embodiments, the node A may send one or more measurements on the one or more reflected first reference signals to another node (e.g., a sensing management function or a server UE) that performs sensing processing by processing the one or more measurements on the one or more reflected first reference signals shared by the node A.

[0091] At a step 610, based on the first sensing result, the node A obtains a decision on whether to transmit one or more second reference signals based on one or more triggering conditions. The one or more second reference signals may include one or more ISAC reference signals. In some embodiments, the node A independently makes a decision to trigger transmission of the one or more second reference signals. In some embodiments, another node makes a decision for node A, based on shared information from node A. The shared information may include the one or more measurements on the one or more reflected first reference signals and / or the first sensing result.

[0092] The one or more triggering conditions used for the one or more second reference signals may include at least one of the one or more measurements on the one or more reflected first reference signals being below or above a corresponding threshold. For example, at least one of a reference signal received power (RSRP), a reference signal received path power (RSRPP), a receive signal strength indicator (RSSI), or a signal to interference plus noise ratio (SINR) of the one or more reflected first reference signals being below or above a corresponding threshold. The one or more triggering conditions may also include at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals being below or above a corresponding threshold. The reference received path power may be any selected path power, for example, a first path power or a strongest path power. The one or more triggering conditions may also include at least one congestion metric associated with the one or more reflected first reference signals being below or above a corresponding threshold. The at least one congestion metric associated with the one or more reflected first reference signals may be a channel busy ratio of the one or more reflected first reference signals. The one or more triggering conditions may also include at least one priority associated with the one or more reflected first reference signals being below or above a corresponding threshold. The at least one priority associated with the one or more reflected first reference signals may include an L1 / L2 band priority, a proximity-based service per-packet priority (PPPP), 5G quality of service (QoS) identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority. The frequency ranges for the L1 band and the L2 band described in the present specification are consistent with the frequency ranges of these bands defined in the 3GPP specifications.

[0093] The one or more triggering conditions may also include control information transmitted from a second node indicates triggering transmission of the one or more second reference signals. The second node may be, for example, a sensing management function or a server UE. The control information transmitted from the second node may be included in at least one of a physical layer signal or medium access control (MAC) layer information. The one or more triggering conditions may also include at least one of the one or more first reference signals including an indicator to trigger transmission of the one or more second reference signals. The indicator may be information included a physical layer signal or MAC layer information. The one or more triggering conditions may also include a higher layer of the node or a second node indicating triggering transmission of the one or more second reference signals. The higher layer may be the application layer of the node A. The second node may be, for example, a sensing management function or a server UE. For example, transmission of the one or more second reference signals is triggered to perform sensing with better accuracy and / or better resolution based on the first sensing result using the one or more first reference signals, or to perform object tracking based on the first sensing result using the one or more first reference signals.

[0094] The one or more triggering conditions may also include the node A entering or leaving a specific geographical region or zone. The specific geographical region or zone may include a highway, an urban scenario, a parking lot, an intersection, or a location with one or more pedestrians. The geographical region or zone may be configured, pre-configured, or pre-defined. The one or more triggering conditions may also include a speed of the node A being below or above a corresponding threshold. The one or more triggering conditions may also include at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals being below or above a corresponding threshold. The one or more mobility characteristics may include at least one of: a location, a direction, and a velocity of at least one object. The one or more triggering conditions may also include at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals being below or above a corresponding threshold. The one or more mobility characteristic changes may include at least one of: a location change, a direction change, and a velocity change of at least one object. The one or more triggering conditions may also include at least one sensing characteristic for the one or more first reference signals not meeting a sensing requirement. The one or more sensing characteristics may include at least one of: a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for the one or more reflected first reference signals.

[0095] The one or more triggering conditions may also include a change of at least one of a lighting condition or a weather condition associated with the node A. The change of at least one of a lighting condition or a weather condition associated with the node A may include, for example, low lighting, heavy rain, snow, or fog. The one or more triggering conditions may also include a confidence of the first sensing result being below or above a corresponding threshold. The one or more triggering conditions may also include an accuracy of the first sensing result being below or above a corresponding threshold. The one or more triggering conditions may also include at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type. For example, the node A may be a vehicle, a base station, or a pedestrian. The target node type may be configured, pre-configured, or pre-defined. The one or more triggering conditions may also include at least one of the one or more objects detected by using the one or more first reference signals being a specific type of object. For example, the at least one object may be a vehicle, a pedestrian, or an animal. The target object type may be configured, pre-configured, or pre-defined.

[0096] Still referring to FIG. 6, at a step 612, based on a decision to transmit the one or more second reference signals, the node A transmits the one or more second reference signals. In some embodiments, the one or more second reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). In some embodiments, one or more parameter values of the one or more second reference signals may be adapted based on the first sensing result. The one or more parameters may include carrier frequency, bandwidth, waveform, beam width, beam direction, and transmission power. For example, in some embodiments, a higher carrier frequency, a wider bandwidth, a narrower beam width, and / or a higher transmission power may be used for the one or more second reference signals to improve sensing accuracy.

[0097] At a step 614, the one or more second reference signals are reflected by the one or more objects. At a step 616, the node A receives one or more reflected second reference signals. At a step 618, the node A obtains a second sensing result based on processing of the one or more reflected second reference signals. In some embodiments, the second sensing result may be determined by processing one or more measurements on the one or more reflected second references signals, to sense the one or more objects. In some embodiments, the second sensing result may be determined by processing the one or more measurements on the one or more reflected second references signals, in combination with the one or more measurements on the one or more reflected first reference signals, and / or the first sensing result. In some embodiments, the node A may obtain the second sensing result independently based on its own processing. In some embodiments, the node A may share the sensing information (e.g., the one or more measurements on the one or more reflected second reference signals, the one or more measurements on the one or more reflected first reference signals, and / or the first sensing result) with another node which processes the sensing information and obtains the second sensing result for the node A. In some embodiments, the node A may transmit one or more subsequent reference signals (e.g., third, fourth, etc.) until a desired accuracy of the sensing is achieved. While the vertical axes in FIG. 6 through FIG. 13 represent time, the durations of the events illustrated in these figures are not represented to scale.

[0098] FIG. 7 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure. Referring to FIG. 7, a node A and a node B may be the nodes capable of mono-static sensing. For example, each of the node A and the node B may include a sensing transmitter, such as the sensing transmitter 102 of FIG. 1, and a sensing receiver, such as the sensing receiver 104 of FIG. 1. At a step 702, the node A transmits one or more first reference signals. The one or more first reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). At a step 704, the one or more first reference signals are reflected from one or more objects. The one or more objects may be any objects surrounding the node A and the node B. At a step 706, the node A receives the one or more reflected first reference signals. At a step 708, the node A obtains a first sensing result based on processing of the one or more reflected first reference signals to sense the one or more objects. In some embodiments, the node A may obtain the first sensing result by itself by processing the one or more reflected first reference signals. In some embodiments, the node A may send one or more measurements on the one or more reflected first reference signals to the node B or another node (e.g., a sensing management function or a server UE) that performs processing the one or more measurements on the one or more reflected first reference signals shared by the node A.

[0099] At a step 710, based on the first sensing result, the node A sends a request for one or more second reference signals to the node B to request the node B to send the one or more second reference signals. The request may also include the one or more measurements on the one or more reflected first reference signals and / or the first sensing result. At a step 712, the node B receives the request sent from the node A. At a step 714, the node B obtains a decision on whether to transmit the one or more second reference signals based on one or more triggering conditions. The one or more triggering conditions may be similar to that described above with respect to FIG. 6; however, for FIG. 7, there are two nodes to be considered. For example, one of the triggering conditions for FIG. 7 includes a higher layer (e.g., application layer) of at least one of the node A, the node B, or a different node (e.g., sensing management function, server UE) indicating triggering transmission of the one or more second reference signals. The one or more second reference signals may include one or more ISAC reference signals. In some embodiments, the node B independently makes a decision to trigger transmission of the one or more second reference signals. In some embodiments, another node (e.g., a sensing management function, or a server UE) makes a decision for node B, based on shared information from node B. The shared information may include the one or more measurements on the one or more reflected first reference signals and / or the first sensing result.

[0100] At a step 716, based on a decision to transmit the one or more second reference signals, the node B transmits the one or more second reference signals. In some embodiments, the one or more second reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). In some embodiments, one or more parameter values of the one or more second reference signals may be adapted based on the first sensing result. The one or more parameters may include carrier frequency, bandwidth, waveform, beam width, beam direction, and transmission power. For example, in some embodiments, a higher carrier frequency, a wider bandwidth, a narrower beam width, and / or a higher transmission power may be used for the one or more second reference signals to improve sensing accuracy.

[0101] At a step 718, the one or more second reference signals are reflected from the one or more objects. At a step 720, the node B receives one or more reflected second reference signals. At a step 722, the node B obtains a second sensing result based on processing of the one or more reflected second reference signals. In some embodiments, the second sensing result may be determined by processing one or more measurements on the one or more reflected second references signals, to sense the one or more objects. In some embodiments, the second sensing result may be determined by processing the one or more measurements on the one or more reflected second references signals, in combination with the one or more measurements on the one or more reflected first reference signals, and / or the first sensing result received from the node A. In some embodiments, the node B may obtain the second sensing result independently based on its own processing. In some embodiments, the node A or the node B may share the sensing information (e.g., the one or more measurements on the one or more reflected second reference signals, the one or more measurements on the one or more reflected first reference signals, and / or the first sensing result) with another node which processes the sensing information and obtains the second sensing result for the node B. In some embodiments, the node B or the node A may transmit one or more subsequent reference signals (e.g., third, fourth, etc.) until a desired sensing accuracy is achieved.

[0102] FIG. 8 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure. Referring to FIG. 8, a node A may include a sensing transmitter, such as the sensing transmitter 202 of FIG. 2, and a node B may include a sensing receiver, such as the sensing receiver 204 of FIG. 2. At a step 802, the node A transmits one or more first reference signals. The one or more first reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). At a step 804, the one or more first reference signals are reflected from one or more objects. The one or more objects may be any objects surrounding the node A and / or the node B. At a step 806, the node B receives the one or more reflected first reference signals. In addition to the one or more reflected first reference signals, the node B also receives the one or more first reference signals (LOS signals) transmitted from the node A. At a step 808, the node B obtains a first sensing result based on processing of the LOS signals and / or the one or more reflected first reference signals to sense the one or more objects. In some embodiments, the node B may obtain the first sensing result independently by processing the one or more reflected first reference signals. In some embodiments, the node B may send one or more measurements on the LOS signals and / or the one or more reflected first reference signals to the node A or another node (e.g., a sensing management function or a server UE) that performs processing of the one or more measurements and obtains the first sensing result for the node B.

[0103] At a step 810, the node B sends a request for one or more second reference signals to the node A requesting the node A to transmit the one or more second reference signals. The request may include the first sensing result, the one or more measurements on the LOS signals and / or the one or more reflected first reference signals. At a step 812, the node A receives the request. At a step 814, the node A obtains a decision on whether to transmit the one or more second reference signals based on one or more triggering conditions. The one or more second reference signals may include one or more ISAC reference signals. In some embodiments, the node A independently makes a decision to trigger transmission of the one or more second reference signals. In some embodiments, another node makes a decision for node A, based on shared information from node A. The shared information may include the first sensing result, and / or the one or more measurements on the LOS signals, and / or the one or more measurements on the one or more reflected first reference signals.

[0104] The one or more triggering conditions used for the one or more second reference signals may include at least one of the one or more measurements on the one or more reflected first reference signals being below or above a corresponding threshold. For example, at least one of a RSRP, a RSRPP, a RSSI, or a SINR of the one or more reflected first reference signals being below or above a corresponding threshold. The one or more triggering conditions may also include at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals being below or above a corresponding threshold. The reference received path power may be any selected path power, for example, a first path power or a strongest path power. The one or more triggering conditions may also include at least one congestion metric associated with the one or more reflected first reference signals being below or above a corresponding threshold. The at least one congestion metric associated with the one or more reflected first reference signals may be a channel busy ratio of the one or more reflected first reference signals. The one or more triggering conditions may also include at least one priority associated with the one or more reflected first reference signals being below or above a corresponding threshold. The at least one priority associated with the one or more reflected first reference signals may include an L1 / L2 band priority, a PPPP, 5G QoS identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority.

[0105] The one or more triggering conditions may also include control information transmitted from the node B or another node (a sensing management function or a server UE) indicating triggering transmission of the one or more second reference signals. The control information transmitted from the node B or another node may be included in at least one of a physical layer signal or MAC layer information. The one or more triggering conditions may also include at least one of the one or more first reference signals including an indicator to trigger transmission of the one or more second reference signals. The indicator may be information included a physical layer signal or MAC layer information. The one or more triggering conditions may also include a higher layer of the node A, the node B, or another node indicating triggering transmission of the one or more second reference signals. The higher layer may be the application layer. For example, transmission of the one or more second reference signals is triggered to perform sensing with better accuracy and / or better resolution based on the first sensing result using the one or more first reference signals, or to perform object tracking based on the first sensing result using the one or more first reference signals.

[0106] The one or more triggering conditions may also include the node A and / or the node B entering or leaving a specific geographical region or zone. The specific geographical region or zone may include a highway, an urban scenario, a parking lot, an intersection, or a location with one or more pedestrians. The geographical region or zone may be configured, pre-configured, or pre-defined. The one or more triggering conditions may also include an absolute speed of the node A and / or the node B being below or above a corresponding threshold. The one or more triggering conditions may also include the separation distance and / or a relative speed between the node A and the node B are below or above a threshold. The one or more triggering conditions may also include at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals being below or above a corresponding threshold. The one or more mobility characteristics may include at least one of: a location, a direction, and a velocity of at least one object. The one or more triggering conditions may also include at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals being below or above a corresponding threshold. The one or more mobility characteristic changes may include at least one of: a location change, a direction change, and a velocity change of at least one object. The one or more triggering conditions may also include at least one sensing characteristic for the one or more first reference signals not meeting a sensing requirement. The one or more sensing characteristics may include at least one of: a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for the one or more reflected first reference signals.

[0107] The one or more triggering conditions may also include a change of at least one of a lighting condition or a weather condition associated with the node A and / or the node B. The change of at least one of a lighting condition or a weather condition associated with the node A may include, for example, low lighting, heavy rain, snow, or fog. The one or more triggering conditions may also include a confidence of the first sensing result being below or above a corresponding threshold. The one or more triggering conditions may also include an accuracy of the first sensing result being below or above a corresponding threshold. The one or more triggering conditions may also include at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type. For example, the node A and / or the node B may be a vehicle, a base station, or a pedestrian. The target node type may be configured, pre-configured, or pre-defined. The one or more triggering conditions may also include at least one of the one or more objects detected by using the one or more first reference signals being a specific type of object. For example, the at least one object may be a vehicle, a pedestrian, or an animal. The target object type may be configured, pre-configured, or pre-defined.

[0108] Still referring to FIG. 8, at a step 816, based on a decision to transmit the one or more second reference signals, the node A transmits the one or more second reference signals. In some embodiments, the one or more second reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). In some embodiments, one or more parameter values of the one or more second reference signals may be adapted based on the first sensing result. The one or more parameters may include carrier frequency, bandwidth, waveform, beam width, beam direction, and transmission power. For example, in some embodiments, a higher carrier frequency, a wider bandwidth, a narrower beam width, and / or a higher transmission power may be used for the one or more second reference signals to improve sensing accuracy.

[0109] At a step 818, the one or more second reference signals are reflected from the one or more objects. At a step 820, the node B may receive one or more reflected second reference signals. In addition to the one or more reflected second reference signals, the node B may also receive the one or more second reference signals (LOS signals) transmitted from the node A. At a step 822, the node B obtains a second sensing result based on processing of the LOS signals and / or the one or more reflected second reference signals. In some embodiments, the second sensing result may be determined by processing one or more measurements on the LOS signals and / or one or more measurements on the one or more reflected second references signals, to sense the one or more objects. In some embodiments, the second sensing result may be determined by additionally processing the one or more measurement on the first reference signals (the LOS and / or the reflected), and / or the first sensing result. In some embodiments, the node B may obtain the second sensing result independently based on its own processing. In some embodiments, the node B may share the sensing information (e.g., the one or more measurements on the one or more reflected second reference signals, the one or more measurements on the second LOS signal, the one or more measurements on the one or more reflected first reference signals, the one or more measurements on the first LOS signal, the first sensing result, and / or the second sensing result) with another node which processes the sensing information and obtains the second sensing result for the node B. In some embodiments, the node A may transmit one or more subsequent reference signals (e.g., third, fourth, etc.) until a desired accuracy of the sensing is achieved.

[0110] FIG. 9 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure. Referring to FIG. 9, each of a node A and a node B may include a sensing transmitter, such as the sensing transmitter 102 of FIG. 1, and a sensing receiver, such as the sensing receiver 104 of FIG. 1. At a step 902, the node A transmits one or more first reference signals. The one or more first reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). At a step 904, the one or more first reference signals are reflected from one or more objects. The one or more objects may be any objects surrounding the node A and / or the node B. At a step 906, the node B may receive the one or more reflected first reference signals. In addition to the one or more reflected first reference signals, the node B may also receive the one or more first reference signals (LOS signals) transmitted from the node A. In some embodiments, the node B may only receive the LOS signals or the one or more reflected first reference signals. At a step 908, the node B obtains a first sensing result based on processing of the one or more reflected first reference signals and / or the LOS signals to sense the one or more objects. In some embodiments, the node B may independently obtain the first sensing result by processing the one or more reflected first reference signals and / or the LOS signals. In some embodiments, the node B may send one or more measurements on the one or more reflected first reference signals and / or the LOS signals to the node A or another node (e.g., a sensing management function or a server UE) that performs processing the one or more measurements on the one or more reflected first reference signals and / or the LOS signals.

[0111] At a step 910, the node B obtains a decision on whether to transmit the one or more second reference signals based on one or more triggering conditions. The one or more triggering conditions may be similar to that described above with respect to FIG. 8. The one or more second reference signals may include one or more ISAC reference signals. In some embodiments, the node B independently makes a decision to trigger transmission of the one or more second reference signals. In some embodiments, another node (e.g., a sensing management function, or a server UE) makes a decision for node B, based on shared information from node B. The shared information may include the first sensing result, the one or more measurements on the one or more reflected first reference signals and / or the LOS signals.

[0112] At a step 912, based on a decision to transmit the one or more second reference signals, the node B transmits the one or more second reference signals. In some embodiments, the one or more second reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). In some embodiments, one or more parameter values of the one or more second reference signals may be adapted based on the first sensing result. The one or more parameters may include carrier frequency, bandwidth, waveform, beam width, beam direction, and transmission power. For example, in some embodiments, a higher carrier frequency, a wider bandwidth, a narrower beam width, and / or a higher transmission power may be used for the one or more second reference signals to improve sensing accuracy.

[0113] At a step 914, the one or more second reference signals are reflected from the one or more objects. At a step 916, the node A receives one or more reflected second reference signals. In addition to the one or more reflected second reference signals, the node A may also receive the one or more second reference signals (LOS signals) transmitted from the node B. At a step 918, the node A obtains a second sensing result based on processing of the one or more reflected second reference signals. In some embodiments, the second sensing result may be determined by processing one or more measurements on the one or more reflected second references signals and / or the LOS signals, to sense the one or more objects. In some embodiments, the second sensing result may be determined by additionally processing the one or more measurements on the one or more reflected first reference signals and / or the first LOS signals, and / or the first sensing result received from the node B. In some embodiments, the node A may obtain the second sensing result independently based on its own processing. In some embodiments, the node A may share the sensing information (e.g., the one or more measurements on the one or more reflected second reference signals and / or the second LOS signals, the one or more measurements on the one or more reflected first reference signals, the first LOS signals, and / or the first sensing result) with another node which processes the sensing information and obtains the second sensing result for the node A. In some embodiments, the node A or the node B may transmit one or more subsequent reference signals (e.g., third, fourth, etc.) until a desired sensing accuracy is achieved.

[0114] FIG. 10 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure. Referring to FIG. 10, a node A may include both a sensing transmitter and a sensing receiver, and a node B may include at least a sensing receiver. At a step 1002, the node A transmits one or more first reference signals. The one or more first reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). At a step 1004, the one or more first reference signals are reflected from one or more objects. The one or more objects may be any objects surrounding the node A and / or the node B. At a step 1006, the node A may receive the one or more reflected first reference signals. At a step 1008, the node A obtains a first sensing result based on processing of the one or more reflected first reference signals to sense the one or more objects. In some embodiments, the node A may independently obtain the first sensing result by processing the one or more reflected first reference signals. In some embodiments, the node A may send one or more measurements on the one or more reflected first reference signals to the node B or another node (e.g., a sensing management function or a server UE) that performs processing the one or more measurements on the one or more reflected first reference signals.

[0115] At a step 1010, the node A obtains a decision on whether to transmit the one or more second reference signals based on one or more triggering conditions. The one or more triggering conditions may be similar to that described above with respect to FIG. 8. The one or more second reference signals may include one or more ISAC reference signals. In some embodiments, the node A independently makes a decision to trigger transmission of the one or more second reference signals. In some embodiments, the node B or another node (e.g., a sensing management function, or a server UE) makes a decision for node A, based on shared information from node A. The shared information may include the first sensing result, the one or more measurements on the one or more reflected first reference signals.

[0116] At a step 1012, based on a decision to transmit the one or more second reference signals, the node A transmits the one or more second reference signals. In some embodiments, the one or more second reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). In some embodiments, one or more parameter values of the one or more second reference signals may be adapted based on the first sensing result. The one or more parameters may include carrier frequency, bandwidth, waveform, beam width, beam direction, and transmission power. For example, in some embodiments, a higher carrier frequency, a wider bandwidth, a narrower beam width, and / or a higher transmission power may be used for the one or more second reference signals to improve sensing accuracy.

[0117] At a step 1014, the one or more second reference signals are reflected from the one or more objects. At a step 1016, the node B receives one or more reflected second reference signals. In addition to the one or more reflected second reference signals, the node B may also receive the one or more second reference signals (LOS signals) transmitted from the node A. At a step 1018, the node B obtains a second sensing result based on processing of the one or more reflected second reference signals and / or the LOS signals. In some embodiments, the second sensing result may be determined by processing one or more measurements on the one or more reflected second references signals and / or the LOS signals, to sense the one or more objects. In some embodiments, the second sensing result may be determined by additionally processing the one or more measurements on the one or more reflected first reference signals and / or the first sensing result received from the node A. In some embodiments, the node B may obtain the second sensing result independently based on its own processing. In some embodiments, the node B may share the sensing information (e.g., the one or more measurements on the one or more reflected second reference signals and / or the second LOS signals, the one or more measurements on the one or more reflected first reference signals, and / or the first sensing result) with another node which processes the sensing information and obtains the second sensing result for the node B. In some embodiments, the node A may transmit one or more subsequent reference signals (e.g., third, fourth, etc.) until a desired sensing accuracy is achieved.

[0118] FIG. 11 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure. Referring to FIG. 11, a node A may include both a sensing transmitter and a sensing receiver, and a node B may include at least a sensing transmitter. At a step 1102, the node A transmits one or more first reference signals. The one or more first reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). At a step 1104, the one or more first reference signals are reflected from one or more objects. The one or more objects may be any objects surrounding the node A and / or the node B. At a step 1106, the node A may receive the one or more reflected first reference signals. At a step 1108, the node A obtains a first sensing result based on processing of the one or more reflected first reference signals to sense the one or more objects. In some embodiments, the node A may independently obtain the first sensing result by processing the one or more reflected first reference signals. In some embodiments, the node A may send one or more measurements on the one or more reflected first reference signals to the node B or another node (e.g., a sensing management function or a server UE) that performs processing the one or more measurements on the one or more reflected first reference signals.

[0119] At a step 1110, the node A sends a request to the node B to request the node B to transmit one or more second reference signals. The request may also include the one or more measurements on the one or more reflected first reference signals and / or the first sensing result. At a step 1112, the node B obtains a decision on whether to transmit the one or more second reference signals based on one or more triggering conditions. The one or more triggering conditions may be similar to that described above with respect to FIG. 8. The one or more second reference signals may include one or more ISAC reference signals. In some embodiments, the node B independently makes a decision to trigger transmission of the one or more second reference signals. In some embodiments, the node A or another node (e.g., a sensing management function, or a server UE) makes a decision for the node B, based on shared information from the node B. The shared information may include the first sensing result and / or the one or more measurements on the one or more reflected first reference signals.

[0120] At a step 1114, based on a decision to transmit the one or more second reference signals, the node B transmits the one or more second reference signals. In some embodiments, the one or more second reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). In some embodiments, one or more parameter values of the one or more second reference signals may be adapted based on the first sensing result. The one or more parameters may include carrier frequency, bandwidth, waveform, beam width, beam direction, and transmission power. For example, in some embodiments, a higher carrier frequency, a wider bandwidth, a narrower beam width, and / or a higher transmission power may be used for the one or more second reference signals to improve sensing accuracy.

[0121] At a step 1116, the one or more second reference signals are reflected by the one or more objects. At a step 1118, the node A receives one or more reflected second reference signals. In addition to the one or more reflected second reference signals, the node A may also receive the one or more second reference signals (LOS signals) transmitted from the node B. At a step 1120, the node A obtains a second sensing result based on processing of the one or more reflected second reference signals and / or the LOS signals. In some embodiments, the second sensing result may be determined by processing the one or more measurements on the one or more reflected second references signals and / or the LOS signals, to sense the one or more objects. In some embodiments, the second sensing result may be determined by additionally processing the one or more measurements on the one or more reflected first reference signals and / or the first sensing result. In some embodiments, the node A may obtain the second sensing result independently based on its own processing. In some embodiments, the node A may share the sensing information (e.g., the one or more measurements on the one or more reflected second reference signals and / or the LOS signals, the one or more measurements on the one or more reflected first reference signals, and / or the first sensing result) with another node which processes the sensing information and obtains the second sensing result for the node A. In some embodiments, the node A or the node B may transmit one or more subsequent reference signals (e.g., third, fourth, etc.) until a desired sensing accuracy is achieved.

[0122] FIG. 12 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure. Referring to FIG. 12, a node A may include both a sensing transmitter and a sensing receiver, and a node B may include at least a sensing transmitter. At a step 1202, the node A transmits one or more first reference signals. The one or more first reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). At a step 1204, the one or more first reference signals are reflected from one or more objects. The one or more objects may be any objects surrounding the node A and / or the node B. At a step 1206, the node B may receive the one or more reflected first reference signals. Alternatively or additionally, the node B may receive the one or more first reference signals transmitted from the node A. At a step 1208, the node B obtains a first sensing result based on processing of the one or more reflected first reference signals and / or the LOS signals, to sense the one or more objects. In some embodiments, the node B may independently obtain the first sensing result by processing the one or more reflected first reference signals and / or the LOS signals. In some embodiments, the node B may send the one or more measurements on the one or more reflected first reference signals and / or the LOS signals to the node A or another node (e.g., a sensing management function or a server UE) that performs processing the one or more measurements on the one or more reflected first reference signals and / or the LOS signals.

[0123] At a step 1210, the node B sends a request to the node A to request the node A to transmit one or more second reference signals. The request may also include the first sensing result, the one or more measurements on the one or more reflected first reference signals and / or the LOS signals. At a step 1212, the node A receives the request. At a step 1214, the node A obtains a decision on whether to transmit the one or more second reference signals based on one or more triggering conditions. The one or more triggering conditions may be similar to that described above with respect to FIG. 8. The one or more second reference signals may include one or more ISAC reference signals. In some embodiments, the node A independently makes a decision to trigger transmission of the one or more second reference signals. In some embodiments, the node B or another node (e.g., a sensing management function, or a server UE) makes a decision for the node A, based on shared information from the node A. The shared information may include the first sensing result, the one or more measurements on the one or more reflected first reference signals and / or the LOS signals.

[0124] At a step 1216, based on a decision to transmit the one or more second reference signals, the node A transmits the one or more second reference signals. In some embodiments, the one or more second reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). In some embodiments, one or more parameter values of the one or more second reference signals may be adapted based on the first sensing result. The one or more parameters may include carrier frequency, bandwidth, waveform, beam width, beam direction, and transmission power. For example, in some embodiments, a higher carrier frequency, a wider bandwidth, a narrower beam width, and / or a higher transmission power may be used for the one or more second reference signals to improve sensing accuracy.

[0125] At a step 1218, the one or more second reference signals are reflected from the one or more objects. At a step 1220, the node A receives one or more reflected second reference signals. At a step 1222, the node A obtains a second sensing result based on processing of the one or more reflected second reference signals. In some embodiments, the second sensing result may be determined by processing the one or more measurements on the one or more reflected second references signals, to sense the one or more objects. In some embodiments, the second sensing result may be determined by additionally processing the one or more measurements on the one or more reflected first reference signals and / or the LOS signals, and / or the first sensing result. In some embodiments, the node A may obtain the second sensing result independently based on its own processing. In some embodiments, the node A may share the sensing information (e.g., the one or more measurements on the one or more reflected second reference signals, the one or more measurements on the one or more reflected first reference signals and / or the LOS signals, and / or the first sensing result) with another node which processes the sensing information and obtains the second sensing result for the node A. In some embodiments, the node A may transmit one or more subsequent reference signals (e.g., third, fourth, etc.) until a desired sensing accuracy is achieved.

[0126] FIG. 13 is a schematic diagram illustrating a sensing procedure, consistent with some embodiments of the present disclosure. Referring to FIG. 13, a node A may include at least a sensing transmitter, and a node B may include both a sensing transmitter and a sensing receiver. At a step 1302, the node A transmits one or more first reference signals. The one or more first reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). At a step 1304, the one or more first reference signals are reflected from one or more objects. The one or more objects may be any objects surrounding the node A and / or the node B. At a step 1306, the node B may receive the one or more reflected first reference signals. Alternatively or additionally, the node B may receive the one or more first reference signals (LOS signals) transmitted from the node A. At a step 1308, the node B obtains a first sensing result based on processing of the one or more reflected first reference signals and / or the LOS signals, to sense the one or more objects. In some embodiments, the node B may independently obtain the first sensing result by processing the one or more reflected first reference signals and / or the LOS signals. In some embodiments, the node B may send the one or more measurements on the one or more reflected first reference signals and / or the LOS signals to the node A or another node (e.g., a sensing management function or a server UE) that performs processing the one or more measurements on the one or more reflected first reference signals and / or the LOS signals.

[0127] At a step 1310, the node B obtains a decision on whether to transmit the one or more second reference signals based on one or more triggering conditions. The one or more triggering conditions may be similar to that described above with respect to FIG. 8. In some embodiments, the node B independently makes a decision to trigger transmission of the one or more second reference signals. In some embodiments, the node A or another node (e.g., a sensing management function, or a server UE) makes a decision for the node B, based on shared information from the node B. The shared information may include the first sensing result, the one or more measurements on the one or more reflected first reference signals and / or the LOS signals.

[0128] At a step 1312, based on a decision to transmit the one or more second reference signals, the node B transmits the one or more second reference signals. In some embodiments, the one or more second reference signals may include at least one of: CSI-RS, SRS, DMRS, SS, PT-RS, PRS, or ISAC reference signal(s). In some embodiments, one or more parameter values of the one or more second reference signals may be adapted based on the first sensing result. The one or more parameters may include carrier frequency, bandwidth, waveform, beam width, beam direction, and transmission power. For example, in some embodiments, a higher carrier frequency, a wider bandwidth, a narrower beam width, and / or a higher transmission power may be used for the one or more second reference signals to improve sensing accuracy.

[0129] At a step 1314, the one or more second reference signals are reflected from the one or more objects. At a step 1316, the node B receives one or more reflected second reference signals. At a step 1318, the node B obtains a second sensing result based on processing of the one or more reflected second reference signals. In some embodiments, the second sensing result may be determined by processing the one or more measurements on the one or more reflected second references signals, to sense the one or more objects. In some embodiments, the second sensing result may be determined by additionally processing the one or more measurements on the one or more reflected first reference signals and / or the LOS signals, and / or the first sensing result. In some embodiments, the node B may obtain the second sensing result independently based on its own processing. In some embodiments, the node B may share the sensing information (e.g., the one or more measurements on the one or more reflected second reference signals, the one or more measurements on the one or more reflected first reference signals and / or the LOS signals, and / or the first sensing result) with another node which processes the sensing information and obtains the second sensing result for the node B. In some embodiments, the node A or the node B may transmit one or more subsequent reference signals (e.g., third, fourth, etc.) until a desired sensing accuracy is achieved.

[0130] FIG. 14 is a flow chart illustrating a method for a first node for a communication, consistent with some embodiments of the present disclosure. The first node may include at least one of: a base station, a core network, a UE, a road-side unit (RSU), a repeater, a transponder, a wireless router, a controller, or an access point. For example, the first node may be the system 100 of FIG. 1, the node 302 of FIG. 3A, the node 306 of FIG. 3B, the node A of FIG. 6, or the node A of FIG. 10.

[0131] Referring to FIG. 14, a method 1400 includes a step 1402 of transmitting one or more first reference signals. The one or more first reference signals may include at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals.

[0132] The method 1400 includes a step 1404 of receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects. The one or more objects may be any object in the environment of the first node.

[0133] The method 1400 includes a step 1406 of obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals. For example, in some embodiments, the first node may determine the first sensing result based on the processing of the one or more measurements on the one or more reflected first reference signals. In some embodiments, the first node may receive, from a second node, the first sensing result determined by the second node. The second node may determine the first sensing result based on the one or more measurements on the one or more reflected first reference signals provided by the first node. The second node may include at least one of: a sensing management function node or a server UE.

[0134] The method 1400 includes a step 1408 of obtaining a decision on whether to transmit one or more second reference signals, the decision being made based on the first sensing result. In some embodiments, the first node determines the decision on whether to transmit the one or more second reference signals, based on the first sensing result. In some embodiments, the first node may receive, from a second node, the decision made by the second node. The second node may make the decision based on information provided by the first node. The information may include at least one of: the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0135] The method 1400 includes a step 1410 of transmitting the one or more second reference signals, based on the decision. For example, the one or more second reference signals may include at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals. The one or more second reference signals may be generated by adjusting one or more parameter values of the one or more first reference signals based on the first sensing result. The one or more parameter values may include at least one of: a carrier frequency, a bandwidth, a waveform, a beam width, a beam direction, or a transmission power.

[0136] Transmitting the one or more second reference signals may be triggered by at least one of a plurality of triggering conditions. The plurality of triggering conditions may include at least one of: (1) at least one of the one or more measurements on the one or more reflected first reference signals is below or above a corresponding threshold, (2) at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals is below or above a corresponding threshold, (3) at least one congestion metric associated with the one or more reflected first reference signals is below or above a corresponding threshold, (4) at least one priority associated with the one or more reflected first reference signals is below or above a corresponding threshold, (5) control information transmitted from a second node indicates triggering transmission of the one or more second reference signals, (6) at least one of the one or more first reference signals includes an indicator to trigger transmission of the one or more second reference signals, (7) a higher layer of the node or a second node indicates triggering transmission of the one or more second reference signals, (8) the node enters or leaves a specific geographical region or zone, (9) a speed of the node is below or above a corresponding threshold, (10) at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (11) at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (12) at least one sensing characteristic for the one or more first reference signals does not meet a sensing requirement, (13) a change of at least one of a lighting condition or a weather condition associated with the node, (14) a confidence of the first sensing result is below or above a corresponding threshold, (15) an accuracy of the first sensing result is below or above a corresponding threshold, (16) at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type, or (17) at least one of the one or more objects detected by using the one or more first reference signals is a specific type of object.

[0137] The at least one congestion metric associated with the one or more reflected first reference signals may include a channel busy ratio. The at least one priority associated with the one or more reflected first reference signals may include an L1 / L2 band priority, a proximity-based service per-packet priority (PPPP), 5G quality of service (QoS) identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority. The control information transmitted from the second node may be included in at least one of a physical layer signal or MAC layer information. The higher layer of the second node may include an application layer of the second node. The specific geographical region or zone may include one or more of: a highway, an urban scenario, a parking lot, an intersection, or a location associated with a pedestrian. The specific geographical region or zone may be configured, pre-configured, or pre-defined. The at least one mobility characteristic of the one or more objects may include a location, a direction, or a velocity of at least one of the one or more objects. The at least one mobility characteristic change of the one or more objects may include a location change, a direction change, or a velocity change of at least one of the one or more objects. The at least one sensing characteristic for the one or more first reference signals may include a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for at least one of the one or more first reference signals. The specific node type may include a vehicle, a base station, or a pedestrian. The specific type of object may include a vehicle, a pedestrian, or an animal. The specific type of object may be configured, pre-configured, or pre-defined. The different triggering conditions among the plurality of triggering conditions trigger different second reference signals.

[0138] In some embodiments, the method 1400 may further include a step (not shown in FIG. 14) of receiving, from the one or more objects, one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects. For example, the first node may receive the one or more reflected second reference signals. In some embodiments, the method may further include a step (not shown in FIG. 14) of obtaining a second sensing result of sensing the one or more objects based on processing of the one or more reflected second reference signals. For example, the first node may obtain the second sensing result. In some embodiments, the first node may obtain the second sensing result based on the processing of the one or more reflected second reference signals and at least one of: the one or more reflected first references signals, or the first sensing result.

[0139] In some embodiments, a first type of signals is used for the one or more first reference signals and a second type of signals is used for the one or more second reference signals. In some embodiments, the first type and the second type are different. In some embodiments, the first type and the second type are the same, and the one or more first reference signals use one or more parameters that are different from one or more parameters used for the one or more second reference signals.

[0140] In some embodiments, the method 1400 may further include a step (not shown in FIG. 14) of transmitting one or more third reference signals, based on at least one of the first sensing result or the second sensing result. The one or more third reference signals are the same as, or different from, at least one of: the one or more first references signals, or the one or more second reference signals. In some embodiments, the method 1400 may further include a step (not shown in FIG. 14) of transmitting one or more fourth reference signals, based on at least one of: the first sensing result, the second sensing result, or a third sensing result determined after transmission of the one or more third reference signals.

[0141] FIG. 15 is a flow chart illustrating a method for a first node for a communication, consistent with some embodiments of the present disclosure. The first node may include at least one of: a base station, a core network, a UE, a road-side unit (RSU), a repeater, a transponder, a wireless router, a controller, or an access point. For example, the first node may be the system 100 of FIG. 1, the node 302 of FIG. 3A, the node 306 of FIG. 3B, or the node A of FIG. 7.

[0142] Referring to FIG. 15, a method 1500 includes a step 1502 of transmitting one or more first reference signals. The one or more first reference signals may include at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals.

[0143] The method 1500 includes a step 1504 of receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects. The one or more objects may be any object in the environment of the first node.

[0144] The method 1500 includes a step 1506 of obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals. For example, in some embodiments, the first node may determine the first sensing result based on processing of the one or more measurements on the one or more reflected first reference signals. In some embodiments, the first node may receive, from a second node or a third node, the first sensing result determined by the second node or the third node based on processing of the one or more measurements on the one or more reflected first reference signals. The one or more measurements on the one or more reflected first reference signals are provided to the second node or the third node by the first node. The third node may include at least one of: a sensing management function node or a server UE.

[0145] The method 1500 includes a step 1508 of transmitting, to a second node, at least one of: a request to transmit one or more second reference signals to the one or more objects, the first sensing result, or the one or more measurements on the one or more reflected first reference signals. For example, the one or more second reference signals may include at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals. The one or more second reference signals may be generated by adjusting one or more parameter values of the one or more first reference signals based on the first sensing result. The one or more parameter values may include at least one of: a carrier frequency, a bandwidth, a waveform, a beam width, a beam direction, or a transmission power. Transmitting the one or more second reference signals may be triggered by at least one of a plurality of triggering conditions as described above with respect to FIG. 8.

[0146] In some embodiments, a first type of signals is used for the one or more first reference signals and a second type of signals is used for the one or more second reference signals. In some embodiments, the first type and the second type are different. In some embodiments, the first type and the second type are the same, and the one or more first reference signals use one or more parameters that are different from one or more parameters used for the one or more second reference signals.

[0147] FIG. 16 is a flow chart illustrating a method for a second node for a communication, consistent with some embodiments of the present disclosure. The second node may include at least one of: a base station, a core network, a UE, an RSU, a repeater, a transponder, a wireless router, a controller, or an access point. For example, the second node may be the system 100 of FIG. 1, the node 302 of FIG. 3A, the node 306 of FIG. 3B, or the node B of FIG. 7.

[0148] Referring to FIG. 16, a method 1600 includes a step 1602 of receiving, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by reflection of one or more first reference signals from one or more objects, or a first sensing result of sensing the one or more objects based on processing of the one or more measurements. The one or more second reference signals may include at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals.

[0149] The method 1600 includes a step 1604 of obtaining a decision on whether to transmit the one or more second reference signals to the one or more objects. In some embodiments, the second node may determine the decision based on at least one of: the request received from the first node, the one or more measurements on the one or more reflected first reference signals received from the first node, or the first sensing result determined by the first node. In some embodiments, the second node may receive, from a first node or a third node, the decision made by the first node or the third node. For example, the third node may make the decision based on processing of information shared by the first node. The information may include at least one of: the first sensing result, or the one or more measurements on the one or more reflected first reference signals. The third node may include at least one of: a sensing management function node or a server UE.

[0150] The method 1600 includes a step 1606 of transmitting the one or more second reference signals, based on the decision. For example, the second node may transmit the one or more second reference signals based on the decision. Transmitting the one or more second reference signals may be triggered by at least one of a plurality of triggering conditions as described above with respect to the FIG. 8.

[0151] The method 1600 includes a step 1608 of receiving, from the one or more objects, one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects. For example, the second node may receive the one or more reflected second reference signals from the one or more objects.

[0152] The method 1600 includes a step 1610 of obtaining a second sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected second reference signals. For example, the second node may obtain the second sensing result based on processing of the one or more measurements on the one or more reflected second reference signals, and at least one of: the one or more measurements on the one or more reflected first reference signals, or the first sensing result.

[0153] FIG. 17 is a flow chart illustrating a method for a first node for a communication, consistent with some embodiments of the present disclosure. The first node may include at least one of: a base station, a core network, a UE, an RSU, a repeater, a transponder, a wireless router, a controller, or an access point. For example, the first node may be the system 100 of FIG. 1, the node 302 of FIG. 3A, the node 306 of FIG. 3B, the node A of FIG. 8, or the node A of FIG. 12.

[0154] Referring to FIG. 17, a method 1700 includes a step 1702 of transmitting one or more first reference signals. The one or more first reference signals may include at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals.

[0155] The method 1700 includes a step 1704 of receiving, from a second node, at least one of: a request to transmit one or more second reference signals, one or more measurements on the one or more first reference signals, one or more measurements on one or more reflected first reference signals received by the second node, or a first sensing result of sensing one or more objects, wherein the one or more reflected first reference signals are formed by reflection of the one or more first reference signals from the one or more objects.

[0156] The method 1700 includes a step 1706 of obtaining a decision on whether to transmit the one or more second reference signals. In some embodiments, the first node may obtain the decision based on its own determination. In some embodiments, the first node may obtain the decision from another node. In some embodiments, the first node may determine the decision based on at least one of: the request received from the second node, the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result. In some embodiments, the first node may receive, from a second node or a third node, the decision made by the second node or the third node. For example, the decision may be made by the third node based on processing of information shared by the second node. The information may include at least one of: the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result.

[0157] In some embodiments, the method 1700 may further include a step (not shown in FIG. 17) of transmitting the one or more second reference signals to at least one of: the second node, or the one or more objects, based on the decision indicating that the one or more second reference signals need to be transmitted from the first node. Transmitting the one or more second reference signals may be triggered by at least one of a plurality of triggering conditions as described above with respect to the FIG. 8.

[0158] In some embodiments, the method 1700 may further include a step (not shown in FIG. 17) of transmitting, to the one or more objects, the one or more second reference signals, based on the decision indicating that the one or more second reference signals need to be transmitted from the first node; receiving one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected second reference signals. For example, the first node may obtain the second sensing result based on processing of the one or more measurements on the one or more reflected second reference signals, and at least one of: the one or more measurements on the one or more first reference signals, the one or more measurements on one or more reflected first reference signals, or the first sensing result.

[0159] FIG. 18 is a flow chart illustrating a method for a second node for a communication, consistent with some embodiments of the present disclosure. The second node may include at least one of: a base station, a core network, a UE, an RSU, a repeater, a transponder, a wireless router, a controller, or an access point. For example, the second node may be the system 100 of FIG. 1, the node 302 of FIG. 3A, the node 306 of FIG. 3B, the node B of FIG. 8, or the node B of FIG. 12.

[0160] Referring to FIG. 18, a method 1800 includes a step 1802 of receiving at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects. The one or more first reference signals may include at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals. The one or more reflected first reference signals may be NLOS signals.

[0161] The method 1800 includes a step 1804 of obtaining a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals received by the second node, or one or more measurements on the one or more reflected first reference signals received by the second node. For example, the second node may obtain the second sensing result based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals, and at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on one or more reflected first reference signals.

[0162] The method 1800 includes a step 1806 of transmitting, to the first node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or a first sensing result, for a determination of a decision on whether the one or more second reference signals need to be transmitted from the first node.

[0163] In some embodiments, the method 1800 may further include a step (not shown in FIG. 18) of receiving at least one of: one or more second reference signals transmitted from the first node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals by the one or more objects; and obtaining a second sensing result based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals. For example, a first type of signals is used for the one or more first reference signals and a second type of signals is used for the one or more second reference signals. In some embodiments, the first type and the second type are different. In some embodiments, the first type and the second type are the same, and the one or more first reference signals use one or more parameters that are different from one or more parameters used for the one or more second reference signals.

[0164] In some embodiments, the method 1800 may further include a step (not shown in FIG. 18) of transmitting, to the first node, at least one of: a request to transmit one or more third reference signals, the one or more measurements on the one or more second reference signals, the one or more measurements on the one or more reflected second reference signals, or a second sensing result, for a determination of a decision on whether the one or more third reference signals need to be transmitted from the first node. The method 1800 may further include a step (not shown in FIG. 18) of transmitting, to the first node, at least one of: a request to transmit one or more fourth reference signals, one or more measurements on the one or more third reference signals, one or more measurements on the one or more reflected third reference signals, or a third sensing result, for a determination of a decision on whether the one or more fourth reference signals need to be transmitted from the first node.

[0165] FIG. 19 is a flow chart illustrating a method for a first node for a communication, consistent with some embodiments of the present disclosure. The first node may include at least one of: a base station, a core network, a UE, an RSU, a repeater, a transponder, a wireless router, a controller, or an access point. For example, the second node may be the system 100 of FIG. 1, the node 302 of FIG. 3A, the node 306 of FIG. 3B, or the node A of FIG. 9.

[0166] Referring to FIG. 19, a method 1900 includes a step 1902 of transmitting one or more first reference signals. The one or more first reference signals may include at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals. The one or more reflected first reference signals may be NLOS signals.

[0167] The method 1900 includes a step 1904 of receiving at least one of: one or more second reference signals transmitted from a second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from one or more objects. For example, the first node may receive at least one of: one or more second reference signals transmitted from a second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from one or more objects. The one or more second reference signals may be transmitted from the second node based on a decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0168] The method 1900 includes a step 1906 of obtaining a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals. In some embodiments, the sensing result is a second sensing result, and obtaining the second sensing result further includes determining, by the first node, the second sensing result based on processing of at least one of: the one or more measurements on the one or more second reference signals, or the one or more measurements on the one or more reflected second reference signals, and at least one of: a first sensing result of sensing the one or more object, or one or more measurements on the one or more first reference signals received from the second node.

[0169] In some embodiments, a first type of signals is used for the one or more first reference signals and a second type of signals is used for the one or more second reference signals. In some embodiments, the first type and the second type are different. In some embodiments, the first type and the second type are the same, and the one or more first reference signals use one or more parameters that are different from one or more parameters used for the one or more second reference signals.

[0170] FIG. 20 is a flow chart illustrating a method for a second node for a communication, consistent with some embodiments of the present disclosure. The second node may include at least one of: a base station, a core network, a UE, an RSU, a repeater, a transponder, a wireless router, a controller, or an access point. For example, the second node may be the system 100 of FIG. 1, the node 302 of FIG. 3A, the node 306 of FIG. 3B, the node B of FIG. 9, or the node B of FIG. 13.

[0171] Referring to FIG. 20, a method 2000 includes a step 2002 of receiving at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects. The one or more first reference signals may include at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals. The one or more reflected first reference signals may be NLOS signals.

[0172] The method 2000 includes a step 2004 of obtaining a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals, or one or more measurements on the one or more reflected first reference signals. For example, the second node may obtain the second sensing result based on processing of the one or more measurements on the one or more reflected second reference signals, and at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on the one or more reflected first reference signals.

[0173] The method 2000 includes a step 2006 of obtaining a decision on whether to transmit one or more second reference signals. In some embodiments, the second node may determine the decision based on processing of at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on the one or more reflected first reference signals. In some embodiments, the second node may receive, from a first node or a third node, the decision made by the first node or the third node. For example, the decision may be made by the third node based on processing of information shared by the second node, the information comprising one or more measurements on at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on the one or more reflected first reference signals.

[0174] The method 2000 includes a step 2008 of transmitting the one or more second reference signals, based on the decision indicating that the one or more second reference signals need to be transmitted from the second node. Transmitting the one or more second reference signals may be triggered by at least one of a plurality of triggering conditions described above with respect to FIG. 9 or FIG. 13.

[0175] FIG. 21 is a flow chart illustrating a method for a second node for a communication, consistent with some embodiments of the present disclosure. The second node may include at least one of: a base station, a core network, a UE, an RSU, a repeater, a transponder, a wireless router, a controller, or an access point. For example, the second node may be the system 100 of FIG. 1, the node 302 of FIG. 3A, the node 306 of FIG. 3B, or the node B of FIG. 10.

[0176] Referring to FIG. 21, a method 2100 includes a step 2102 of receiving at least one of: one or more reference signals transmitted from a first node, or one or more reflected reference signals formed by reflection of the one or more reference signals from one or more objects. The one or more first reference signals may include at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals. The one or more reflected first reference signals may be NLOS signals.

[0177] The method 2100 includes a step 2104 of obtaining a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more reference signals, or one or more measurements on the one or more reflected reference signals. The one or more reference signals may be transmitted from a first node based on a decision indicating that the one or more reference signals need to be transmitted from the first node.

[0178] In some embodiments, the one or more reference signals are one or more second reference signals and the sensing result is a second sensing result, and obtaining the second sensing result may further include obtaining the second sensing result based on processing of at least one of: the one or more measurements on the one or more reference signals, or the one or more measurements on the one or more reflected reference signals, and at least one of: a first sensing result, or one or more measurements on one or more reflected first reference signals.

[0179] FIG. 22 is a flow chart illustrating a method for a first node for a communication, consistent with some embodiments of the present disclosure. The first node may include at least one of: a base station, a core network, a UE, an RSU, a repeater, a transponder, a wireless router, a controller, or an access point. For example, the first node may be the system 100 of FIG. 1, the node 302 of FIG. 3A, the node 306 of FIG. 3B, or the node A of FIG. 11.

[0180] Referring to FIG. 22, a method 2200 includes a step 2202 of transmitting one or more first reference signals. The one or more first reference signals may include at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals. The one or more reflected first reference signals may be NLOS signals.

[0181] The method 2200 includes a step 2204 of receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects.

[0182] The method 2200 includes a step 2206 of obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals.

[0183] The method 2200 includes a step 2208 of transmitting, to a second node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result.

[0184] The method 2200 includes a step 2210 of receiving at least one of: one or more second reference signals transmitted from the second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects.

[0185] The method 2200 includes a step 2212 of obtaining a second sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals. In some embodiments, obtaining the second sensing result is based on processing of at least one of: the one or more measurements on the one or more second reference signals, or the one or more measurements on the one or more reflected second reference signals, and at least one of: the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0186] FIG. 23 is a flow chart illustrating a method for a second node for a communication, consistent with some embodiments of the present disclosure. The second node may include at least one of: a base station, a core network, a UE, an RSU, a repeater, a transponder, a wireless router, a controller, or an access point. For example, the first node may be the system 100 of FIG. 1, the node 302 of FIG. 3A, the node 306 of FIG. 3B, or the node B of FIG. 11.

[0187] Referring to FIG. 23, a method 2300 includes a step 2302 of receiving, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by one or more first reference signal transmitted from the first node and reflected from the one or more objects, or a first sensing result obtained based on the one or more measurements.

[0188] The method 2300 includes a step 2304 of obtaining a decision on whether to transmit the one or more second reference signals. In some embodiments, the first node may determine the decision based on at least one of: the request received from the first node, the one or more measurements, or the first sensing result. In some embodiments, the first node may receive, from the first node or a third node, the decision made by the first node or the third node. For example, the decision may be made by the third node based on processing of information shared by the first node, the information comprising at least one of: the one or more measurements on the one or more reflected first reference signals, or the first sensing result.

[0189] The method 2300 includes a step 2306 of transmitting the one or more second reference signals based on the decision indicating that the one or more second reference signals need to be transmitted from the second node. The one or more second reference signals may include at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals. The one or more second reference signals may be generated by adjusting one or more parameter values of the one or more first reference signals based on the first sensing result. The one or more parameters may include at least one of: a carrier frequency, a bandwidth, a waveform, a beam width, a beam direction, or a transmission power.

[0190] FIG. 24 is a block diagram of a node 2400, consistent with some embodiments of the present disclosure. In some embodiments, the node 2400 may be a node that sends reference signals to other nodes. In some embodiments, the node 1100 may be capable of mono-static sending, such as the system 100 of FIG. 1, the node 302 of FIG. 3A, or the node 306 of FIG. 3B. In some embodiments, the node 2400 may be capable of transmitting reference signals in bi-static sensing, such as the node 310 of FIG. 3C, the node 316 of FIG. 3D, the node 322 of FIG. 3E, or the node 328 of FIG. 3F. In some embodiments, the node 2400 may be capable of receiving reference signals in bi-static sensing, such as the node 312 of FIG. 3C, the node 318 of FIG. 3D, the node 324 of FIG. 3E, or the node 330 of FIG. 3F. In some embodiments, the node 2400 may be a node that performs the method 1400 of FIG. 14, the method 1500 of FIG. 15, the method 1600 of FIG. 16, the method 1700 of FIG. 17, the method 1800 of FIG. 18, the method 1900 of FIG. 19, the method 2000 of FIG. 20, the method 2100 of FIG. 21, the method 2200 of FIG. 22, or the method 2300 of FIG. 23.

[0191] Referring to FIG. 24, the node 2400 may include antenna 2402 that may be used for transmission or reception of electromagnetic signals to / from one or more other nodes. The antenna 2402 may include one or more antenna elements and may enable different input-output antenna configurations, for example, multiple input multiple output (MIMO) configuration, multiple input single output (MISO) configuration, and single input multiple output (SIMO) configuration. In some embodiments, the antenna 2402 may include multiple (e.g., tens or hundreds) antenna elements and may enable multi-antenna functions such as beamforming. In some embodiments, the antenna 2402 is a single antenna.

[0192] The node 2400 may include a transceiver 2404 that is coupled to the antenna 2402. The transceiver 2404 may be a wireless transceiver at the node 2400 and may communicate bi-directionally with one or more other nodes. For example, the transceiver 2404 may receive / transmit wireless signals from / to a base station via downlink / uplink communication. The transceiver 2404 may also receive / transmit wireless signals from / to another node unit via sidelink communication. The transceiver 2404 may also transmit wireless signals to one or more objects and receive signals reflected from the one or more objects. For example, the transceiver 2404 may have a configuration and / or capabilities of the sensing transmitter 102 and / or the sensing receiver 104 of FIG. 1. The transceiver 2404 may include a modem to modulate the packets and provide the modulated packets to the antenna 2402 for transmission, and to demodulate packets received from the antenna 2402. The transceiver 2404 may have a configuration and / or capabilities of extracting information (e.g., OFDM patterns, delay of arrival, angle-of-arrival, Doppler of received signals) and provide the information to the processor 2408 so that the processor 2408 perform computation based on the received information.

[0193] The node 2400 may include a memory 2406. The memory 2406 may be any type of computer-readable storage medium including volatile or non-volatile memory devices, or a combination thereof. The computer-readable storage medium includes, but is not limited to, non-transitory computer storage media. A non-transitory storage medium may be accessed by a general purpose or special purpose computer. Examples of non-transitory storage medium include, but are not limited to, a portable computer diskette, a hard disk, random access memory (RAM), read-only memory (ROM), an erasable programmable read-only memory (EPROM), electrically erasable programmable ROM (EEPROM), a digital versatile disk (DVD), flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, etc. A non-transitory medium may be used to carry or store desired program code means (e.g., instructions and / or data structures) and may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. In some examples, the software / program code may be transmitted from a remote source (e.g., a website, a server, etc.) using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave. In such examples, the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are within the scope of the definition of medium. The memory 2406 may also be a cloud-based remote memory device. Combinations of the above examples are also within the scope of computer-readable medium.

[0194] The memory 2406 may store information related to identities of node 2400 and the signals and / or data received by antenna 2402. The memory 2406 may also store post-processing signals and / or data. The memory 2406 may also store computer-readable program instructions, mathematical models, and algorithms that are used in signal processing in receiver 2404 and computations in processor 2408. The memory 2406 may further store computer-readable program instructions for execution by processor 2408 to operate the node 2400 to perform various functions described in this disclosure. The memory may further store paging information received from a network node or relayed from a relay node. In some examples, the memory 2406 may include a basic input / output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

[0195] The computer-readable program instructions of the present disclosure may be assembler instructions, instruction-set-architecture (ISA) instructions, machine instructions, machine-dependent instructions, microcode, firmware instructions, state-setting data, or source code or object code written in any combination of one or more programming languages, including an object-oriented programming language, and conventional procedural programming languages. The computer-readable program instructions may execute entirely on a computing device as a stand-alone software package, or partly on a first computing device and partly on a second computing device remote from the first computing device. In the latter scenario, the second, remote computing device may be connected to the first computing device through any type of network, including a local area network (LAN) or a wide area network (WAN).

[0196] The node 2400 may include a processor 2408 that may include a hardware device with processing capabilities. The processor 2408 may include at least one of a general-purpose processor, a digital signal processor (DSP), a central processing unit (CPU), a graphical processing unit (GPU), a microcontroller, an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or other programmable logic device. Examples of the general-purpose processor include, but are not limited to, a microprocessor, any conventional processor, a controller, a microcontroller, or a state machine. In some embodiments, the processor 2408 may be implemented using a combination of devices (e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration). The processor 2408 may receive, from transceiver 2404 sensing data and further process the sensing data. In some embodiments, the processor 2408 may be configured to operate a memory using a memory controller. In some embodiments, a memory controller may be integrated into the processor 2408. The processor 2408 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 2406) to cause the node 2400 to perform various functions. The processor 2408 may be configured or programmed to execute the instructions stored in the memory 2406 to perform the method 1400 of FIG. 14, the method 1500 of FIG. 15, the method 1600 of FIG. 16, the method 1700 of FIG. 17, the method 1800 of FIG. 18, the method 1900 of FIG. 19, the method 2000 of FIG. 20, the method 2100 of FIG. 21, the method 2200 of FIG. 22, or the method 2300 of FIG. 23. For example, in some embodiments, the processor 2408 may have a configuration and / or capabilities of extracting information (e.g., OFDM patterns, delay of arrival, angle-of-arrival, and Doppler of the received signals) from the wireless signals received from the transceiver 2402 and perform computation based on the information to obtain characteristics (e.g., position, velocity, acceleration, angle, shape, etc.) of one or more objects. In some embodiments, the transceiver 2404 may have a configuration and / or capabilities of extracting the information (e.g., OFDM patterns, delay of arrival, angle-of-arrival, and Doppler of the received signals) and provide the information to the processor 2408 so that the processor 2408 perform computation based on the received information.

[0197] The node 2400 may include a global positioning system (GPS) 2410. The GPS 2410 may be used for enabling location-based services or other services based on a geographical position of the node 2400 and / or synchronization among nodes. The GPS 2410 may receive global navigation satellite systems (GNSS) signals from a single satellite or a plurality of satellite signals via the antenna 2402 and provide a geographical position of the node 2400 (e.g., coordinates of the node 2400). In some embodiments, the GPS 2410 is omitted. In some embodiments, a timer is included.

[0198] The node 2400 may include an input / output (I / O) device 2412 that may be used to communicate a result of signal processing and computation to a user or another device. The I / O device 2412 may include a user interface including a display and an input device to transmit a user command to processor 2408. The display may be configured to display a status of signal reception at the node 2400, the data stored at memory 1106, a status of signal processing, and a result of computation, etc. The display may include, but is not limited to, a cathode ray tube (CRT), a liquid crystal display (LCD), a light-emitting diode (LED), a gas plasma display, a touch screen, or other image projection devices for displaying information to a user. The input device may be any type of computer hardware equipment used to receive data and control signals from a user. The input device may include, but is not limited to, a keyboard, a mouse, a scanner, a digital camera, a joystick, a trackball, cursor direction keys, a touchscreen monitor, or audio / video commanders, etc.

[0199] The node 2400 may further include a machine interface 2414, such as an electrical bus that connects the transceiver 2404, the memory 2406, the processor 2408, the GPS 2410, and the I / O device 2412.

[0200] As used in this disclosure, use of the term “or” in a list of items indicates an inclusive list. The list of items may be prefaced by a phrase such as “at least one of” or “one or more of.” For example, a list of at least one of A, B, or C includes A or B or C or AB (i.e., A and B) or AC or BC or ABC (i.e., A and B and C). Also, as used in this disclosure, prefacing a list of conditions with the phrase “based on” shall not be construed as “based only on” the set of conditions and rather shall be construed as “based at least in part on” the set of conditions. For example, an outcome described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of this disclosure.

[0201] In this specification, the terms “comprise,” “include,” or “contain” may be used interchangeably and have the same meaning and are to be construed as inclusive and open-ended. The terms “comprise,” “include,” or “contain” may be used before a list of elements and indicate that at least all of the listed elements within the list exist but other elements that are not in the list may also be present. For example, if A comprises B and C, both {B, C} and {B, C, D} are within the scope of A.

[0202] The present disclosure, in connection with the accompanied drawings, describes example configurations that are not representative of all the examples that may be implemented or all configurations that are within the scope of this disclosure. The term “exemplary” should not be construed as “preferred” or “advantageous compared to other examples” but rather “an illustration, an instance or an example.” By reading this disclosure, including the description of the embodiments and the drawings, it will be appreciated by a person of ordinary skills in the art that the technology disclosed herein may be implemented using alternative embodiments. The person of ordinary skill in the art would appreciate that the embodiments, or certain features of the embodiments described herein, may be combined to arrive at yet other embodiments for practicing the technology described in the present disclosure. Thus, the disclosure is not limited to the examples and designs described herein but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

[0203] The flowcharts and block diagrams in the figures illustrate examples of the architecture, functionality, and operation of possible implementations of systems, methods, and devices according to various embodiments. It should be noted that, in some alternative implementations, the functions noted in blocks may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Likewise, additional steps may be included in such methods, and certain steps may be omitted or combined, in methods consistent with various embodiments.

[0204] It is understood that the described embodiments are not mutually exclusive, and elements, components, materials, or steps described in connection with one example embodiment may be combined with, or eliminated from, other embodiments in suitable ways to accomplish desired design objectives.

[0205] Reference herein to “some embodiments” or “some exemplary embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiment can be included in at least one embodiment. The appearance of the phrases “one embodiment” “some embodiments” or “another embodiment” in various places in the present disclosure do not all necessarily refer to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments.

[0206] Additionally, the articles “a” and “an” as used in the present disclosure and the appended claims should generally be construed to mean “one or more” unless specified otherwise or clear from context to be directed to a singular form.

[0207] Unless explicitly stated otherwise, each numerical value and range should be interpreted as being approximate as if the word “about” or “approximately” preceded the value of the value or range.

[0208] Although the elements in the following method claims, if any, are recited in a particular sequence, unless the claim recitations otherwise imply a particular sequence for implementing some or all of those elements, those elements are not necessarily intended to be limited to being implemented in that particular sequence.

[0209] It is appreciated that certain features of the present disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the specification, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable subcombination or as suitable in any other described embodiment of the specification. Certain features described in the context of various embodiments are not essential features of those embodiments, unless noted as such.

[0210] It will be further understood that various modifications, alternatives, and variations in the details, materials, and arrangements of the parts which have been described and illustrated in order to explain the nature of described embodiments may be made by those skilled in the art without departing from the scope. Accordingly, the following claims embrace all such alternatives, modifications, and variations that fall within the terms of the claims.

[0211] Clause 1: A method for a node for a communication, the method comprising: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; obtaining a decision on whether to transmit one or more second reference signals, the decision being made based on the first sensing result; and transmitting the one or more second reference signals, based on the decision.

[0212] Clause 2: The method of clause 1, wherein the one or more first reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0213] Clause 3: The method of clause 1, wherein the node is a first node, and wherein obtaining the first sensing result comprises at least one of: determining, by the first node, the first sensing result based on the processing of the one or more measurements on the one or more reflected first reference signals; or receiving, from a second node, the first sensing result determined by the second node, the first sensing result being determined by the second node based on the one or more measurements on the one or more reflected first reference signals provided by the first node.

[0214] Clause 4: The method of clause 3, wherein the second node comprises at least one of: a sensing management function node or a server user equipment (UE).

[0215] Clause 5: The method of clause 1, wherein the one or more second reference signals comprise at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals.

[0216] Clause 6: The method of clause 5, wherein the one or more second reference signals are generated by adjusting one or more parameter values of the one or more first reference signals based on the first sensing result, wherein the one or more parameter values comprise at least one of: a carrier frequency, a bandwidth, a waveform, a beam width, a beam direction, or a transmission power.

[0217] Clause 7: The method of clause 1, wherein the node is a first node, and wherein obtaining the decision comprises at least one of: determining, by the first node and based on the first sensing result, whether to transmit the one or more second reference signals; or receiving, from a second node, the decision made by the second node, the decision being made by the second node based on information provided by the first node, the information comprising at least one of: the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0218] Clause 8: The method of clause 1, further comprising: receiving, from the one or more objects, one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects.

[0219] Clause 9: The method of clause 8, further comprising: obtaining a second sensing result of sensing the one or more objects based on processing of the one or more reflected second reference signals.

[0220] Clause 10: The method of clause 9, further comprising: obtaining the second sensing result based on the processing of the one or more reflected second reference signals and at least one of: the one or more reflected first references signals, or the first sensing result.

[0221] Clause 11: The method of clause 1, wherein the node is a first node, and wherein transmitting the one or more second reference signals is triggered by at least one of a plurality of triggering conditions, and wherein the plurality of triggering conditions comprises: (1) at least one of the one or more measurements on the one or more reflected first reference signals is below or above a corresponding threshold, (2) at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals is below or above a corresponding threshold, (3) at least one congestion metric associated with the one or more reflected first reference signals is below or above a corresponding threshold, (4) at least one priority associated with the one or more reflected first reference signals is below or above a corresponding threshold, (5) control information transmitted from a second node indicates triggering transmission of the one or more second reference signals, (6) at least one of the one or more first reference signals includes an indicator to trigger transmission of the one or more second reference signals, (7) a higher layer of the first node or the second node indicates triggering transmission of the one or more second reference signals, (8) the first node enters or leaves a specific geographical region or zone, (9) a speed of the first node is below or above a corresponding threshold, (10) at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (11) at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (12) at least one sensing characteristic for the one or more first reference signals does not meet a sensing requirement, (13) a change of at least one of a lighting condition or a weather condition associated with the node, (14) a confidence of the first sensing result is below or above a corresponding threshold, (15) an accuracy of the first sensing result is below or above a corresponding threshold, (16) at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type, and (17) at least one of the one or more objects detected by using the one or more first reference signals is a specific type of object.

[0222] Clause 12: The method of clause 11, wherein the at least one congestion metric associated with the one or more reflected first reference signals comprises a channel busy ratio.

[0223] Clause 13: The method of clause 11, wherein the at least one priority associated with the one or more reflected first reference signals comprises an L1 / L2 band priority, a proximity-based service per-packet priority (PPPP), 5G quality of service (QoS) identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority.

[0224] Clause 14: The method of clause 11, wherein the control information transmitted from the second node is included in at least one of a physical layer signal or medium access control (MAC) layer information.

[0225] Clause 15: The method of clause 11, wherein the higher layer of the second node comprises an application layer of the second node.

[0226] Clause 16: The method of clause 11, wherein the specific geographical region or zone comprises one or more of: a highway, an urban scenario, a parking lot, an intersection, or a location associated with a pedestrian.

[0227] Clause 17: The method of clause 11, wherein the specific geographical region or zone is configured, pre-configured, or pre-defined.

[0228] Clause 18: The method of clause 11, wherein at least one mobility characteristic of the one or more objects comprises a location, a direction, or a velocity of at least one of the one or more objects.

[0229] Clause 19: The method of clause 11, wherein at least one mobility characteristic change of the one or more objects comprises a location change, a direction change, or a velocity change of at least one of the one or more objects.

[0230] Clause 20: The method of clause 11, wherein the at least one sensing characteristic for the one or more first reference signals comprises a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for at least one of the one or more first reference signals.

[0231] Clause 21: The method of clause 11, wherein the specific node type comprises a vehicle, a base station, or a pedestrian.

[0232] Clause 22: The method of clause 11, wherein the specific node type is configured, pre-configured, or pre-defined.

[0233] Clause 23: The method of clause 11, wherein the specific type of object comprises a vehicle, a pedestrian, or an animal.

[0234] Clause 24: The method of clause 11, wherein the specific type of object is configured, pre-configured, or pre-defined.

[0235] Clause 25: The method of clause 11, wherein different triggering conditions among the plurality of triggering conditions trigger different second reference signals.

[0236] Clause 26: The method of clause 1, wherein a first type of signals is used for the one or more first reference signals and a second type of signals is used for the one or more second reference signals.

[0237] Clause 27: The method of clause 26, wherein the first type and the second type are different.

[0238] Clause 28: The method of clause 26, wherein the first type and the second type are the same, and the one or more first reference signals use one or more parameters that are different from one or more parameters used for the one or more second reference signals.

[0239] Clause 29: The method of clause 1, further comprising: transmitting one or more third reference signals, based on at least one of the first sensing result or the second sensing result.

[0240] Clause 30: The method of clause 29, wherein the one or more third reference signals are the same as, or different from, at least one of: the one or more first references signals, or the one or more second reference signals.

[0241] Clause 31: The method of clause 29, further comprising: transmitting one or more fourth reference signals, based on at least one of: the first sensing result, the second sensing result, or a third sensing result determined after transmission of the one or more third reference signals.

[0242] Clause 32: A method for a first node for a communication, the method comprising: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; and transmitting, to a second node, at least one of: a request to transmit one or more second reference signals to the one or more objects, the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0243] Clause 33: The method of clause 32, wherein the one or more first reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0244] Clause 34: The method of clause 32, wherein obtaining the first sensing result further comprises at least one of: determining, by the first node, the first sensing result based on processing of the one or more measurements on the one or more reflected first reference signals; or receiving, from the second node or a third node, the first sensing result determined by the second node or the third node based on processing of the one or more measurements on the one or more reflected first reference signals, the one or more measurements on the one or more reflected first reference signals being provided to the second node or the third node by the first node.

[0245] Clause 35: The method of clause 34, wherein the third node comprises at least one of: a sensing management function node or a server UE.

[0246] Clause 36: The method of clause 32, wherein the one or more second reference signals comprise at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals.

[0247] Clause 37: A method for a second node for a communication, the method comprising: receiving, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by reflection of one or more first reference signals from one or more objects, or a first sensing result of sensing the one or more objects based on processing of the one or more measurements; obtaining a decision on whether to transmit the one or more second reference signals to the one or more objects; transmitting the one or more second reference signals, based on the decision; receiving, from the one or more objects, one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected second reference signals.

[0248] Clause 38: The method of clause 37, wherein the one or more second reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0249] Clause 39: The method of clause 37, wherein obtaining the second sensing result comprises: obtaining the second sensing result based on processing of the one or more measurements on the one or more reflected second reference signals, and at least one of: the one or more measurements on the one or more reflected first reference signals, or the first sensing result.

[0250] Clause 40: The method of clause 37, wherein obtaining the decision further comprises at least one of: determining, by the second node, the decision based on at least one of: the request received from the first node, the one or more measurements on the one or more reflected first reference signals received from the first node, or the first sensing result determined by the first node; or receiving, from the first node or a third node, the decision made by the first node or the third node, the decision being made by the third node based on processing of information shared by the first node, the information comprising at least one of: the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0251] Clause 41: The method of clause 40, wherein the third node comprises at least one of: a sensing management function node or a server UE.

[0252] Clause 42: The method of clause 37, wherein transmitting the one or more second reference signals is triggered by at least one of a plurality of triggering conditions, and wherein the plurality of triggering conditions comprises: (1) at least one of the one or more measurements on the one or more reflected first reference signals is below or above a corresponding threshold, (2) at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals is below or above a corresponding threshold, (3) at least one congestion metric associated with the one or more reflected first reference signals is below or above a corresponding threshold, (4) at least one priority associated with the one or more reflected first reference signals is below or above a corresponding threshold, (5) control information transmitted from the first node or a third node indicates triggering transmission of the one or more second reference signals, (6) at least one of the one or more first reference signals includes an indicator to trigger transmission of the one or more second reference signals, (7) a higher layer of the second node or the first second node or the third node indicates triggering transmission of the one or more second reference signals, (8) the second node or the first node enters or leaves a specific geographical region or zone, (9) a speed of the second node or the first node is below or above a corresponding threshold, (10) at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (11) at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (12) at least one sensing characteristic for the one or more first reference signals does not meet a sensing requirement, (13) a change of at least one of a lighting condition or a weather condition associated with the second node or the first node, (14) a confidence of the first sensing result is below or above a corresponding threshold, (15) an accuracy of the first sensing result is below or above a corresponding threshold, (16) at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type, and (17) at least one of the one or more objects detected by using the one or more first reference signals is a specific type of object.

[0253] Clause 43: The method of clause 42, wherein the at least one congestion metric associated with the one or more reflected first reference signals comprises a channel busy ratio.

[0254] Clause 44: The method of clause 42, wherein the at least one priority associated with the one or more reflected first reference signals comprises an L1 / L2 band priority, a proximity-based service per-packet priority (PPPP), 5G quality of service (QoS) identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority.

[0255] Clause 45: The method of clause 42, wherein the control information transmitted from the second node is included in at least one of a physical layer signal or medium access control (MAC) layer information.

[0256] Clause 46: The method of clause 42, wherein the higher layer comprises an application layer.

[0257] Clause 47: The method of clause 42, wherein the specific geographical region or zone comprises one or more of: a highway, an urban scenario, a parking lot, an intersection, or a location associated with a pedestrian.

[0258] Clause 48: The method of clause 42, wherein the specific geographical region or zone is configured, pre-configured, or pre-defined.

[0259] Clause 49: The method of clause 42, wherein at least one mobility characteristic of the one or more objects comprises a location, a direction, or a velocity of at least one of the one or more objects.

[0260] Clause 50: The method of clause 42, wherein at least one mobility characteristic change of the one or more objects comprises a location change, a direction change, or a velocity change of at least one of the one or more objects.

[0261] Clause 51: The method of clause 42, wherein the at least one sensing characteristic for the one or more first reference signals comprises a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for at least one of the one or more first reference signals.

[0262] Clause 52: The method of clause 42, wherein the specific node type comprises a vehicle, a base station, or a pedestrian.

[0263] Clause 53: The method of clause 42, wherein the specific node type is configured, pre-configured, or pre-defined.

[0264] Clause 54: The method of clause 42, wherein the specific type of object comprises a vehicle, a pedestrian, or an animal.

[0265] Clause 55: The method of clause 42, wherein the specific type of object is configured, pre-configured, or pre-defined.

[0266] Clause 56: The method of clause 42, wherein different triggering conditions among the plurality of triggering conditions trigger different second reference signals.

[0267] Clause 57: The method of clause 37, wherein a first type of signals is used for the one or more first reference signals and a second type of signals is used for the one or more second reference signals.

[0268] Clause 58: The method of clause 57, wherein the first type and the second type are different.

[0269] Clause 59: The method of clause 57, wherein the first type and the second type are the same, and the one or more first reference signals use one or more parameters that are different from one or more parameters used for the one or more second reference signals.

[0270] Clause 60: The method of clause 37, further comprising: transmitting one or more third reference signals, based on at least one of the first sensing result or the second sensing result.

[0271] Clause 61: The method of clause 60, wherein the one or more third reference signals are the same as, or different from, at least one of: the one or more first references signals, or the one or more second reference signals.

[0272] Clause 62: The method of clause 60, further comprising: transmitting one or more fourth reference signals, based on at least one of: the first sensing result, the second sensing result, or a third sensing result determined after transmission of the one or more third reference signals.

[0273] Clause 63: A method for a first node for a communication, the method comprising: transmitting one or more first reference signals; receiving, from a second node, at least one of: a request to transmit one or more second reference signals, one or more measurements on the one or more first reference signals, one or more measurements on one or more reflected first reference signals received by the second node, or a first sensing result of sensing one or more objects, wherein the one or more reflected first reference signals are formed by reflection of the one or more first reference signals from the one or more objects; and obtaining a decision on whether to transmit the one or more second reference signals.

[0274] Clause 64: The method of clause 63, further comprising: transmitting the one or more second reference signals to at least one of: the second node, or the one or more objects, based on the decision indicating that the one or more second reference signals need to be transmitted from the first node.

[0275] Clause 65: The method of clause 63, further comprising: transmitting, to the one or more objects, the one or more second reference signals, based on the decision indicating that the one or more second reference signals need to be transmitted from the first node; receiving one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more; and obtaining a second sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected second reference signals.

[0276] Clause 66: The method of clause 65, wherein obtaining the second sensing result further comprises: obtaining the second sensing result based on processing of the one or more measurements on the one or more reflected second reference signals, and at least one of: the one or more measurements on the one or more first reference signals, the one or more measurements on one or more reflected first reference signals, or the first sensing result.

[0277] Clause 67: The method of clause 63, wherein obtaining the decision comprises at least one of: determining, by the first node, the decision based on at least one of: the request received from the second node, the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result; or receiving, from the second node or a third node, the decision made by the second node or the third node, the decision being made by the third node based on processing of information shared by the second node, the information comprising at least one of: the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result.

[0278] Clause 68: The method of clause 67, wherein the third node comprises at least one of: a sensing management function node or a server UE.

[0279] Clause 69: The method of clause 63, wherein the one or more first reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0280] Clause 70: The method of clause 63, wherein the one or more second reference signals comprise at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals.

[0281] Clause 71: The method of clause 70, wherein the one or more second reference signals are generated by adjusting one or more parameter values of the one or more first reference signals based on the first sensing result, wherein the one or more parameter values comprise at least one of: a carrier frequency, a bandwidth, a waveform, a beam width, a beam direction, or a transmission power.

[0282] Clause 72: The method of clause 63, wherein transmitting the one or more second reference signals is triggered by at least one of a plurality of triggering conditions, and wherein the plurality of triggering conditions comprises: (1) at least one of the one or more measurements on the one or more reflected first reference signals is below or above a corresponding threshold, (2) at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals is below or above a corresponding threshold, (3) at least one congestion metric associated with the one or more reflected first reference signals is below or above a corresponding threshold, (4) at least one priority associated with the one or more reflected first reference signals is below or above a corresponding threshold, (5) control information transmitted from the second node or a third node indicates triggering transmission of the one or more second reference signals, (6) at least one of the one or more first reference signals includes an indicator to trigger transmission of the one or more second reference signals, (7) a higher layer of the first node or the second node or the third node indicates triggering transmission of the one or more second reference signals, (8) the first node or the second node enters or leaves a specific geographical region or zone, (9) a speed of the first node or the second node is below or above a corresponding threshold, (10) a relative speed between the first node and the second node is below or above a corresponding threshold, (11) a separation distance between the first node and the second node is below or above a threshold, (12) at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (13) at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (14) at least one sensing characteristic for the one or more first reference signals does not meet a sensing requirement, (15) a change of at least one of a lighting condition or a weather condition associated with the node, (16) a confidence of the first sensing result is below or above a corresponding threshold, (17) an accuracy of the first sensing result is below or above a corresponding threshold, (18) at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type, and (19) at least one of the one or more objects detected by using the one or more first reference signals is a specific type of object.

[0283] Clause 73: The method of clause 72, wherein the at least one congestion metric associated with the one or more reflected first reference signals comprises a channel busy ratio.

[0284] Clause 74: The method of clause 72, wherein the at least one priority associated with the one or more reflected first reference signals comprises an L1 / L2 band priority, a proximity-based service per-packet priority (PPPP), 5G quality of service (QoS) identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority.

[0285] Clause 75: The method of clause 72, wherein the control information transmitted from the second node is included in at least one of a physical layer signal or medium access control (MAC) layer information.

[0286] Clause 76: The method of clause 72, wherein the higher layer comprises an application layer.

[0287] Clause 77: The method of clause 72, wherein the specific geographical region or zone comprises one or more of: a highway, an urban scenario, a parking lot, an intersection, or a location associated with a pedestrian.

[0288] Clause 78: The method of clause 72, wherein the specific geographical region or zone is configured, pre-configured, or pre-defined.

[0289] Clause 79: The method of clause 72, wherein at least one mobility characteristic of the one or more objects comprises a location, a direction, or a velocity of at least one of the one or more objects.

[0290] Clause 80: The method of clause 72, wherein at least one mobility characteristic change of the one or more objects comprises a location change, a direction change, or a velocity change of at least one of the one or more objects.

[0291] Clause 81: The method of clause 72, wherein the at least one sensing characteristic for the one or more first reference signals comprises a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for at least one of the one or more first reference signals.

[0292] Clause 82: The method of clause 72, wherein the specific node type comprises a vehicle, a base station, or a pedestrian.

[0293] Clause 83: The method of clause 72, wherein the specific node type is configured, pre-configured, or pre-defined.

[0294] Clause 84: The method of clause 72, wherein the specific type of object comprises a vehicle, a pedestrian, or an animal.

[0295] Clause 85: The method of clause 72, wherein the specific type of object is configured, pre-configured, or pre-defined.

[0296] Clause 86: The method of clause 72, wherein different triggering conditions among the plurality of triggering conditions trigger different second reference signals.

[0297] Clause 87: The method of clause 63, wherein a first type of signals is used for the one or more first reference signals and a second type of signals is used for the one or more second reference signals.

[0298] Clause 88: The method of clause 87, wherein the first type and the second type are different.

[0299] Clause 89: The method of clause 87, wherein the first type and the second type are the same, and the one or more first reference signals use one or more parameters that are different from one or more parameters used for the one or more second reference signals.

[0300] Clause 90: The method of clause 65, further comprising: transmitting one or more third reference signals, based on at least one of: a request for the one or more third reference signals, the first sensing result, or the second sensing result.

[0301] Clause 91: The method of clause 90, wherein the one or more third reference signals are the same as, or different from, at least one of: the one or more first reference signals, or the one or more second reference signals.

[0302] Clause 92: The method of clause 90, further comprising: transmitting one or more fourth reference signals, based on at least one of: a request for the one or more fourth reference signals, the first sensing result, the second sensing result, or a third sensing result determined after transmission of the one or more third reference signals.

[0303] Clause 93: A method for a second node for a communication, the method comprising: receiving at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals received by the second node, or one or more measurements on the one or more reflected first reference signals received by the second node; and transmitting, to the first node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or a first sensing result, for a determination of a decision on whether the one or more second reference signals need to be transmitted from the first node.

[0304] Clause 94: The method of clause 93, further comprising: receiving at least one of: one or more second reference signals transmitted from the first node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals.

[0305] Clause 95: The method of clause 94, wherein obtaining the second sensing result further comprises: obtaining the second sensing result based on processing of at least one of: the one or more measurements on the one or more second reference signals, or the one or more measurements on the one or more reflected second reference signals, and at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on one or more reflected first reference signals.

[0306] Clause 96: The method of clause 94, further comprising: transmitting, to the first node, at least one of: a request to transmit one or more third reference signals, the one or more measurements on the one or more second reference signals, the one or more measurements on the one or more reflected second reference signals, or the second sensing result, for a determination of a decision on whether the one or more third reference signals need to be transmitted from the first node.

[0307] Clause 97: The method of clause 96, further comprising: transmitting, to the first node, at least one of: a request to transmit one or more fourth reference signals, one or more measurements on the one or more third reference signals, one or more measurements on the one or more reflected third reference signals, or a third sensing result, for a determination of a decision on whether the one or more fourth reference signals need to be transmitted from the first node.

[0308] Clause 98: A method for a first node for a communication, the method comprising: transmitting one or more first reference signals; receiving at least one of: one or more second reference signals transmitted from a second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from one or more objects; and obtaining a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals, wherein the one or more second reference signals are transmitted from the second node based on a decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0309] Clause 99: The method of clause 98, wherein the one or more first reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0310] Clause 100: The method of clause 98, wherein the sensing result is a second sensing result, and obtaining the second sensing result further comprises: determining, by the first node, the second sensing result based on processing of at least one of: the one or more measurements on the one or more second reference signals, or the one or more measurements on the one or more reflected second reference signals, and at least one of: a first sensing result of sensing the one or more objects, one or more measurements on the one or more first reference signals, or one or more measurements on one or more reflected first reference signals.

[0311] Clause 101: A method for a second node for a communication, the method comprising: receiving at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals, or one or more measurements on the one or more reflected first reference signals; obtaining a decision on whether to transmit one or more second reference signals; and transmitting the one or more second reference signals, based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0312] Clause 102: The method of clause 101, wherein the one or more second reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0313] Clause 103: The method of clause 101, further comprising: receiving, from the one or more objects, one or more reflected second reference signals that are formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result based on processing of one or more measurements on the one or more reflected second reference signals.

[0314] Clause 104: The method of clause 103, wherein obtaining the second sensing result further comprises: obtaining the second sensing result based on processing of the one or more measurements on the one or more reflected second reference signals, and at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on the one or more reflected first reference signals.

[0315] Clause 105: The method of clause 101, wherein obtaining the decision comprises at least one of: determining, by the second node, based on processing of at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on the one or more reflected first reference signals; or receiving, from the first node or a third node, the decision made by the first node or the third node, the decision being made by the third node based on processing of information shared by the second node, the information comprising one or more measurements on at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on the one or more reflected first reference signals.

[0316] Clause 106: The method of clause 101, wherein transmitting the one or more second reference signals is triggered by at least one of a plurality of triggering conditions, and wherein the plurality of triggering conditions comprises: (1) at least one of the one or more measurements on the one or more reflected first reference signals is below or above a corresponding threshold, (2) at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals is below or above a corresponding threshold, (3) at least one congestion metric associated with the one or more reflected first reference signals is below or above a corresponding threshold, (4) at least one priority associated with the one or more reflected first reference signals is below or above a corresponding threshold, (5) control information transmitted from the first node or a third node indicates triggering transmission of the one or more second reference signals, (6) at least one of the one or more first reference signals includes an indicator to trigger transmission of the one or more second reference signals, (7) a higher layer of the second node or the first node or the third node indicates triggering transmission of the one or more second reference signals, (8) the second node or the first node enters or leaves a specific geographical region or zone, (9) a speed of the second node or the first node is below or above a corresponding threshold, (10) a relative speed between the first node and the second node is below or above a corresponding threshold, (11) a separation distance between the first node and the second node is below or above a threshold, (12) at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (13) at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (14) at least one sensing characteristic for the one or more first reference signals does not meet a sensing requirement, (15) a change of at least one of a lighting condition or a weather condition associated with the node, (16) a confidence of the first sensing result is below or above a corresponding threshold, (17) an accuracy of the first sensing result is below or above a corresponding threshold, (18) at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type, and (19) at least one of the one or more objects detected by using the one or more first reference signals is a specific type of object.

[0317] Clause 107: The method of clause 106, wherein the at least one congestion metric associated with the one or more reflected first reference signals comprises a channel busy ratio.

[0318] Clause 108: The method of clause 106, wherein the at least one priority associated with the one or more reflected first reference signals comprises an L1 / L2 band priority, a proximity-based service per-packet priority (PPPP), 5G quality of service (QoS) identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority.

[0319] Clause 109: The method of clause 106, wherein the control information transmitted from the second node is included in at least one of a physical layer signal or medium access control (MAC) layer information.

[0320] Clause 110: The method of clause 106, wherein the higher layer of the second node comprises an application layer of the second node.

[0321] Clause 111: The method of clause 106, wherein the specific geographical region or zone comprises one or more of: a highway, an urban scenario, a parking lot, an intersection, or a location associated with a pedestrian.

[0322] Clause 112: The method of clause 106, wherein the specific geographical region or zone is configured, pre-configured, or pre-defined.

[0323] Clause 113: The method of clause 106, wherein at least one mobility characteristic of the one or more objects comprises a location, a direction, or a velocity of at least one of the one or more objects.

[0324] Clause 114: The method of clause 106, wherein at least one mobility characteristic change of the one or more objects comprises a location change, a direction change, or a velocity change of at least one of the one or more objects.

[0325] Clause 115: The method of clause 106, wherein the at least one sensing characteristic for the one or more first reference signals comprises a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for at least one of the one or more first reference signals.

[0326] Clause 116: The method of clause 106, wherein the specific node type comprises a vehicle, a base station, or a pedestrian.

[0327] Clause 117: The method of clause 106, wherein the specific node type is configured, pre-configured, or pre-defined.

[0328] Clause 118: The method of clause 106, wherein the specific type of object comprises a vehicle, a pedestrian, or an animal.

[0329] Clause 119: The method of clause 106, wherein the specific type of object is configured, pre-configured, or pre-defined.

[0330] Clause 120: The method of clause 106, wherein different triggering conditions among the plurality of triggering conditions trigger different second reference signals.

[0331] Clause 121: The method of clause 101, wherein a first type of signals is used for the one or more first reference signals and a second type of signals is used for the one or more second reference signals.

[0332] Clause 122: The method of clause 121, wherein the first type and the second type are different.

[0333] Clause 123: The method of clause 121, wherein the first type and the second type are the same, and the one or more first reference signals use one or more parameters that are different from one or more parameters used for the one or more second reference signals.

[0334] Clause 124: The method of clause 101, further comprising: transmitting one or more third reference signals, based on at least one of the first sensing result or a second sensing result.

[0335] Clause 125: The method of clause 124, wherein the one or more third reference signals are the same as, or different from, at least one of: the one or more first references signals, or the one or more second reference signals.

[0336] Clause 126: The method of clause 124, further comprising: transmitting one or more fourth reference signals, based on at least one of: the first sensing result, the second sensing result, or a third sensing result determined after transmission of the one or more third reference signals.

[0337] Clause 127: A method for a second node for a communication, the method comprising: receiving at least one of: one or more reference signals transmitted from a first node, or one or more reflected reference signals formed by reflection of the one or more reference signals from one or more objects; and obtaining a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more reference signals, or one or more measurements on the one or more reflected reference signals, wherein the one or more reference signals are transmitted from a first node based on a decision indicating that the one or more reference signals need to be transmitted from the first node.

[0338] Clause 128: The method of clause 127, wherein the one or more reference signals are one or more second reference signals and the sensing result is a second sensing result, and obtaining the second sensing result further comprises: obtaining the second sensing result based on processing of at least one of: the one or more measurements on the one or more reference signals, or the one or more measurements on the one or more reflected reference signals, and at least one of: a first sensing result, or one or more measurements on one or more reflected first reference signals.

[0339] Clause 129: A method for a first node for a communication, the method comprising: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; transmitting, to a second node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result; receiving at least one of: one or more second reference signals transmitted from the second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals.

[0340] Clause 130: The method of clause 129, wherein the one or more first reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0341] Clause 131: The method of clause 129, wherein obtaining the second sensing result further comprises: obtaining the second sensing result based on processing of at least one of: the one or more measurements on the one or more second reference signals, or the one or more measurements on the one or more reflected second reference signals, and at least one of: the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0342] Clause 132: A method for a second node for a communication, the method comprising: receiving, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by one or more first reference signal transmitted from the first node and reflected from the one or more objects, or a first sensing result obtained based on the one or more measurements; obtaining a decision on whether to transmit the one or more second reference signals; and transmitting the one or more second reference signals based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0343] Clause 133: The method of clause 132, wherein the one or more second reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0344] Clause 134: The method of clause 133, wherein the one or more second reference signals are generated by adjusting one or more parameter values of the one or more first reference signals based on the first sensing result, wherein the one or more parameter values comprise at least one of: a carrier frequency, a bandwidth, a waveform, a beam width, a beam direction, or a transmission power.

[0345] Clause 135: The method of clause 132, wherein obtaining the decision further comprises at least one of: determining, by the second node, the decision based on at least one of: the request received from the first node, the one or more measurements, or the first sensing result; or receiving, from the first node or a third node, the decision made by the first node or the third node, the decision being made by the third node based on processing of information shared by the first node, the information comprising at least one of: the one or more measurements on the one or more reflected first reference signals, or the first sensing result.

[0346] Clause 136: The method of clause 132, wherein transmitting the one or more second reference signals is triggered by at least one of a plurality of triggering conditions, and wherein the plurality of triggering conditions comprises: (1) at least one of the one or more measurements on the one or more reflected first reference signals is below or above a corresponding threshold, (2) at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals is below or above a corresponding threshold, (3) at least one congestion metric associated with the one or more reflected first reference signals is below or above a corresponding threshold, (4) at least one priority associated with the one or more reflected first reference signals is below or above a corresponding threshold, (5) control information transmitted from the second node or the first node or a third node indicates triggering transmission of the one or more second reference signals, (6) at least one of the one or more first reference signals includes an indicator to trigger transmission of the one or more second reference signals, (7) a higher layer of the second node or the second node or the third node indicates triggering transmission of the one or more second reference signals, (8) the second node or the first node enters or leaves a specific geographical region or zone, (9) a speed of the second node or the first node is below or above a corresponding threshold, (10) a relative speed between the first node and the second node is below or above a corresponding threshold, (11) a separation distance between the first node and the second node is below or above a threshold, (12) at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (13) at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (14) at least one sensing characteristic for the one or more first reference signals does not meet a sensing requirement, (15) a change of at least one of a lighting condition or a weather condition associated with the node, (16) a confidence of the first sensing result is below or above a corresponding threshold, (17) an accuracy of the first sensing result is below or above a corresponding threshold, (18) at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type, and (19) at least one of the one or more objects detected by using the one or more first reference signals is a specific type of object.

[0347] Clause 137: The method of clause 136, wherein the at least one congestion metric associated with the one or more reflected first reference signals comprises a channel busy ratio.

[0348] Clause 138: The method of clause 136, wherein the at least one priority associated with the one or more reflected first reference signals comprises an L1 / L2 band priority, a proximity-based service per-packet priority (PPPP), 5G quality of service (QoS) identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority.

[0349] Clause 139: The method of clause 136, wherein the control information transmitted from the second node is included in at least one of a physical layer signal or medium access control (MAC) layer information.

[0350] Clause 140: The method of clause 136, wherein the higher layer of the second node comprises an application layer of the second node.

[0351] Clause 141: The method of clause 136, wherein the specific geographical region or zone comprises one or more of: a highway, an urban scenario, a parking lot, an intersection, or a location associated with a pedestrian.

[0352] Clause 142: The method of clause 136, wherein the specific geographical region or zone is configured, pre-configured, or pre-defined.

[0353] Clause 143: The method of clause 136, wherein at least one mobility characteristic of the one or more objects comprises a location, a direction, or a velocity of at least one of the one or more objects.

[0354] Clause 144: The method of clause 136, wherein at least one mobility characteristic change of the one or more objects comprises a location change, a direction change, or a velocity change of at least one of the one or more objects.

[0355] Clause 145: The method of clause 136, wherein the at least one sensing characteristic for the one or more first reference signals comprises a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for at least one of the one or more first reference signals.

[0356] Clause 146: The method of clause 136, wherein the specific node type comprises a vehicle, a base station, or a pedestrian.

[0357] Clause 147: The method of clause 136, wherein the specific node type is configured, pre-configured, or pre-defined.

[0358] Clause 148: The method of clause 136, wherein the specific type of object comprises a vehicle, a pedestrian, or an animal.

[0359] Clause 149: The method of clause 136, wherein the specific type of object is configured, pre-configured, or pre-defined.

[0360] Clause 150: The method of clause 136, wherein different triggering conditions among the plurality of triggering conditions trigger different second reference signals.

[0361] Clause 151: The method of clause 132, further comprising: transmitting one or more third reference signals, based on at least one of the first sensing result or a second sensing result obtained based on one or more measurements on the one or more second reference signals.

[0362] Clause 152: The method of clause 151, wherein the one or more third reference signals are the same as, or different from, at least one of: the one or more first references signals, or the one or more second reference signals.

[0363] Clause 153: The method of clause 151, further comprising: transmitting one or more fourth reference signals, based on at least one of: the first sensing result, the second sensing result, or a third sensing result determined after transmission of the one or more third reference signals.

[0364] Clause 154: A node for a communication, the node comprising: a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: transmit one or more first reference signals; receive, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtain a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; obtain a decision on whether to transmit one or more second reference signals, the decision being made based on the first sensing result; and transmit the one or more second reference signals, based on the decision.

[0365] Clause 155: The node of clause 154, wherein the one or more first reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0366] Clause 156: The node of clause 154, wherein the node is a first node, and wherein the processor is configured to execute the instruction stored in the memory to: determine, by the first node, the first sensing result based on the processing of the one or more measurements on the one or more reflected first reference signals; or receive, from a second node, the first sensing result determined by the second node, the first sensing result being determined by the second node based on the one or more measurements on the one or more reflected first reference signals provided by the first node.

[0367] Clause 157: The node of clause 156, wherein the second node comprises at least one of: a sensing management function node or a server user equipment (UE).

[0368] Clause 158: The node of clause 154, wherein the one or more second reference signals comprise at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals.

[0369] Clause 159: The node of clause 158, wherein the one or more second reference signals are generated by adjusting one or more parameter values of the one or more first reference signals based on the first sensing result, wherein the one or more parameter values comprise at least one of: a carrier frequency, a bandwidth, a waveform, a beam width, a beam direction, or a transmission power.

[0370] Clause 160: The node of clause 154, wherein the node is a first node, and wherein the processor is configured to execute the instruction stored in the memory to: determine, by the first node and based on the first sensing result, whether to transmit the one or more second reference signals; or receive, from a second node, the decision made by the second node, the decision being made by the second node based on information provided by the first node, the information comprising at least one of: the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0371] Clause 161: The node of clause 154, wherein the processor is configured to execute the instruction stored in the memory to: receive, from the one or more objects, one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects.

[0372] Clause 162: The node of clause 161, wherein the processor is configured to execute the instruction stored in the memory to: obtain a second sensing result of sensing the one or more objects based on processing of the one or more reflected second reference signals.

[0373] Clause 163: The node of clause 162, wherein the processor is configured to execute the instruction stored in the memory to: obtain the second sensing result based on the processing of the one or more reflected second reference signals and at least one of: the one or more reflected first references signals, or the first sensing result.

[0374] Clause 164: The node of clause 154, wherein the node is a first node, and wherein transmitting the one or more second reference signals is triggered by at least one of a plurality of triggering conditions, and wherein the plurality of triggering conditions comprises: (1) at least one of the one or more measurements on the one or more reflected first reference signals is below or above a corresponding threshold, (2) at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals is below or above a corresponding threshold, (3) at least one congestion metric associated with the one or more reflected first reference signals is below or above a corresponding threshold, (4) at least one priority associated with the one or more reflected first reference signals is below or above a corresponding threshold, (5) control information transmitted from a second node indicates triggering transmission of the one or more second reference signals, (6) at least one of the one or more first reference signals includes an indicator to trigger transmission of the one or more second reference signals, (7) a higher layer of the first node or the second node indicates triggering transmission of the one or more second reference signals, (8) the first node enters or leaves a specific geographical region or zone, (9) a speed of the first node is below or above a corresponding threshold, (10) at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (11) at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (12) at least one sensing characteristic for the one or more first reference signals does not meet a sensing requirement, (13) a change of at least one of a lighting condition or a weather condition associated with the node, (14) a confidence of the first sensing result is below or above a corresponding threshold, (15) an accuracy of the first sensing result is below or above a corresponding threshold, (16) at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type, and (17) at least one of the one or more objects detected by using the one or more first reference signals is a specific type of object.

[0375] Clause 165: The node of clause 164, wherein the at least one congestion metric associated with the one or more reflected first reference signals comprises a channel busy ratio.

[0376] Clause 166: The node of clause 164, wherein the at least one priority associated with the one or more reflected first reference signals comprises an L1 / L2 band priority, a proximity-based service per-packet priority (PPPP), 5G quality of service (QoS) identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority.

[0377] Clause 167: The node of clause 164, wherein the control information transmitted from the second node is included in at least one of a physical layer signal or medium access control (MAC) layer information.

[0378] Clause 168: The node of clause 164, wherein the higher layer of the second node comprises an application layer of the second node.

[0379] Clause 169: The node of clause 164, wherein the specific geographical region or zone comprises one or more of: a highway, an urban scenario, a parking lot, an intersection, or a location associated with a pedestrian.

[0380] Clause 170: The node of clause 164, wherein the specific geographical region or zone is configured, pre-configured, or pre-defined.

[0381] Clause 171: The node of clause 164, wherein at least one mobility characteristic of the one or more objects comprises a location, a direction, or a velocity of at least one of the one or more objects.

[0382] Clause 172: The node of clause 164, wherein at least one mobility characteristic change of the one or more objects comprises a location change, a direction change, or a velocity change of at least one of the one or more objects.

[0383] Clause 173: The node of clause 164, wherein the at least one sensing characteristic for the one or more first reference signals comprises a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for at least one of the one or more first reference signals.

[0384] Clause 174: The node of clause 164, wherein the specific node type comprises a vehicle, a base station, or a pedestrian.

[0385] Clause 175: The node of clause 164, wherein the specific node type is configured, pre-configured, or pre-defined.

[0386] Clause 176: The node of clause 164, wherein the specific type of object comprises a vehicle, a pedestrian, or an animal.

[0387] Clause 177: The node of clause 164, wherein the specific type of object is configured, pre-configured, or pre-defined.

[0388] Clause 178: The node of clause 164, wherein different triggering conditions among the plurality of triggering conditions trigger different second reference signals.

[0389] Clause 179: The node of clause 154, wherein a first type of signals is used for the one or more first reference signals and a second type of signals is used for the one or more second reference signals.

[0390] Clause 180: The node of clause 179, wherein the first type and the second type are different.

[0391] Clause 181: The node of clause 179, wherein the first type and the second type are the same, and the one or more first reference signals use one or more parameters that are different from one or more parameters used for the one or more second reference signals.

[0392] Clause 182: The node of clause 162, wherein the processor is configured to execute the instruction stored in the memory to: transmit one or more third reference signals, based on at least one of the first sensing result or the second sensing result.

[0393] Clause 183: The node of clause 182, wherein the one or more third reference signals are the same as, or different from, at least one of: the one or more first references signals, or the one or more second reference signals.

[0394] Clause 184: The node of clause 182, wherein the processor is configured to execute the instruction stored in the memory to: transmit one or more fourth reference signals, based on at least one of: the first sensing result, the second sensing result, or a third sensing result determined after transmission of the one or more third reference signals.

[0395] Clause 185: A first node for a communication, the first node comprising: a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: transmit one or more first reference signals; receive, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtain a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; and transmit, to a second node, at least one of: a request to transmit one or more second reference signals to the one or more objects, the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0396] Clause 186: The first node of clause 185, wherein the one or more first reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0397] Clause 187: The first node of clause 185, wherein the processor is configured to execute the instruction stored in the memory to: determine, by the first node, the first sensing result based on processing of the one or more measurements on the one or more reflected first reference signals; or receive, from the second node or a third node, the first sensing result determined by the second node or the third node based on processing of the one or more measurements on the one or more reflected first reference signals, the one or more measurements on the one or more reflected first reference signals being provided to the second node or the third node by the first node.

[0398] Clause 188: The first node of clause 187, wherein the third node comprises at least one of: a sensing management function node or a server UE.

[0399] Clause 189: The first node of clause 185, wherein the one or more second reference signals comprise at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals.

[0400] Clause 190: A second node for a communication, the second node comprising: a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: receive, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by reflection of one or more first reference signals from one or more objects, or a first sensing result of sensing the one or more objects based on processing of the one or more measurements; obtain a decision on whether to transmit the one or more second reference signals to the one or more objects; transmit the one or more second reference signals, based on the decision; receive, from the one or more objects, one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtain a second sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected second reference signals.

[0401] Clause 191: The second node of clause 190, wherein the one or more second reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0402] Clause 192: The second node of clause 190, wherein the processor is configured to execute the instruction stored in the memory to: obtain the second sensing result based on processing of the one or more measurements on the one or more reflected second reference signals, and at least one of: the one or more measurements on the one or more reflected first reference signals, or the first sensing result.

[0403] Clause 193: The second node of clause 190, wherein the processor is configured to execute the instruction stored in the memory to: determine, by the second node, the decision based on at least one of: the request received from the first node, the one or more measurements on the one or more reflected first reference signals received from the first node, or the first sensing result determined by the first node; or receive, from the first node or a third node, the decision made by the first node or the third node, the decision being made by the third node based on processing of information shared by the first node, the information comprising at least one of: the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0404] Clause 194: The second node of clause 193, wherein the third node comprises at least one of: a sensing management function node or a server UE.

[0405] Clause 195: The second node of clause 190, wherein transmitting the one or more second reference signals is triggered by at least one of a plurality of triggering conditions, and wherein the plurality of triggering conditions comprises: (1) at least one of the one or more measurements on the one or more reflected first reference signals is below or above a corresponding threshold, (2) at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals is below or above a corresponding threshold, (3) at least one congestion metric associated with the one or more reflected first reference signals is below or above a corresponding threshold, (4) at least one priority associated with the one or more reflected first reference signals is below or above a corresponding threshold, (5) control information transmitted from the first node or a third node indicates triggering transmission of the one or more second reference signals, (6) at least one of the one or more first reference signals includes an indicator to trigger transmission of the one or more second reference signals, (7) a higher layer of the second node or the first second node or the third node indicates triggering transmission of the one or more second reference signals, (8) the second node or the first node enters or leaves a specific geographical region or zone, (9) a speed of the second node or the first node is below or above a corresponding threshold, (10) at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (11) at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (12) at least one sensing characteristic for the one or more first reference signals does not meet a sensing requirement, (13) a change of at least one of a lighting condition or a weather condition associated with the second node or the first node, (14) a confidence of the first sensing result is below or above a corresponding threshold, (15) an accuracy of the first sensing result is below or above a corresponding threshold, (16) at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type, and (17) at least one of the one or more objects detected by using the one or more first reference signals is a specific type of object.

[0406] Clause 196: The second node of clause 195, wherein the at least one congestion metric associated with the one or more reflected first reference signals comprises a channel busy ratio.

[0407] Clause 197: The second node of clause 195, wherein the at least one priority associated with the one or more reflected first reference signals comprises an L1 / L2 band priority, a proximity-based service per-packet priority (PPPP), 5G quality of service (QoS) identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority.

[0408] Clause 198: The second node of clause 195, wherein the control information transmitted from the second node is included in at least one of a physical layer signal or medium access control (MAC) layer information.

[0409] Clause 199: The second node of clause 195, wherein the higher layer comprises an application layer.

[0410] Clause 200: The second node of clause 195, wherein the specific geographical region or zone comprises one or more of: a highway, an urban scenario, a parking lot, an intersection, or a location associated with a pedestrian.

[0411] Clause 201: The second node of clause 195, wherein the specific geographical region or zone is configured, pre-configured, or pre-defined.

[0412] Clause 202: The second node of clause 195, wherein at least one mobility characteristic of the one or more objects comprises a location, a direction, or a velocity of at least one of the one or more objects.

[0413] Clause 203: The second node of clause 195, wherein at least one mobility characteristic change of the one or more objects comprises a location change, a direction change, or a velocity change of at least one of the one or more objects.

[0414] Clause 204: The second node of clause 195, wherein the at least one sensing characteristic for the one or more first reference signals comprises a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for at least one of the one or more first reference signals.

[0415] Clause 205: The second node of clause 195, wherein the specific node type comprises a vehicle, a base station, or a pedestrian.

[0416] Clause 206: The second node of clause 195, wherein the specific node type is configured, pre-configured, or pre-defined.

[0417] Clause 207: The second node of clause 195, wherein the specific type of object comprises a vehicle, a pedestrian, or an animal.

[0418] Clause 208: The second node of clause 195, wherein the specific type of object is configured, pre-configured, or pre-defined.

[0419] Clause 209: The second node of clause 195, wherein different triggering conditions among the plurality of triggering conditions trigger different second reference signals.

[0420] Clause 210: The second node of clause 190, wherein a first type of signals is used for the one or more first reference signals and a second type of signals is used for the one or more second reference signals.

[0421] Clause 211: The second node of clause 210, wherein the first type and the second type are different.

[0422] Clause 212: The second node of clause 210, wherein the first type and the second type are the same, and the one or more first reference signals use one or more parameters that are different from one or more parameters used for the one or more second reference signals.

[0423] Clause 213: The second node of clause 190, wherein the processor is configured to execute the instruction stored in the memory to: transmit one or more third reference signals, based on at least one of the first sensing result or the second sensing result.

[0424] Clause 214: The second node of clause 213, wherein the one or more third reference signals are the same as, or different from, at least one of: the one or more first references signals, or the one or more second reference signals.

[0425] Clause 215: The second node of clause 213, further comprising: transmitting one or more fourth reference signals, based on at least one of: the first sensing result, the second sensing result, or a third sensing result determined after transmission of the one or more third reference signals.

[0426] Clause 216: A first node for a communication, the first node comprising: a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: transmit one or more first reference signals; receive, from a second node, at least one of: a request to transmit one or more second reference signals, one or more measurements on the one or more first reference signals, one or more measurements on one or more reflected first reference signals received by the second node, or a first sensing result of sensing one or more objects, wherein the one or more reflected first reference signals are formed by reflection of the one or more first reference signals from the one or more objects; and obtain a decision on whether to transmit the one or more second reference signals.

[0427] Clause 217: The first node of clause 216, further comprising: transmit the one or more second reference signals to at least one of: the second node, or the one or more objects, based on the decision indicating that the one or more second reference signals need to be transmitted from the first node.

[0428] Clause 218: The first node of clause 216, wherein the processor is configured to execute the instruction stored in the memory to: transmit, to the one or more objects, the one or more second reference signals, based on the decision indicating that the one or more second reference signals need to be transmitted from the first node; receive one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtain a second sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected second reference signals.

[0429] Clause 219: The first node of clause 218, wherein the processor is configured to execute the instruction stored in the memory to: obtain the second sensing result based on processing of the one or more measurements on the one or more reflected second reference signals, and at least one of: the one or more measurements on the one or more first reference signals, the one or more measurements on one or more reflected first reference signals, or the first sensing result.

[0430] Clause 220: The first node of clause 216, wherein the processor is configured to execute the instruction stored in the memory to: determine, by the first node, the decision based on at least one of: the request received from the second node, the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result; or receive, from the second node or a third node, the decision made by the second node or the third node, the decision being made by the third node based on processing of information shared by the second node, the information comprising at least one of: the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result.

[0431] Clause 221: The first node of clause 220, wherein the third node comprises at least one of: a sensing management function node or a server UE.

[0432] Clause 222: The first node of clause 216, wherein the one or more first reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0433] Clause 223: The first node of clause 216, wherein the one or more second reference signals comprise at least one of: one or more CSI-RSs, one or more SRSs, one or more DMRSs, one or more SSs, one or more PT-RSs, one or more PRSs, or one or more ISAC reference signals.

[0434] Clause 224: The first node of clause 223, wherein the one or more second reference signals are generated by adjusting one or more parameter values of the one or more first reference signals based on the first sensing result, wherein the one or more parameter values comprise at least one of: a carrier frequency, a bandwidth, a waveform, a beam width, a beam direction, or a transmission power.

[0435] Clause 225: The first node of clause 216, wherein transmitting the one or more second reference signals is triggered by at least one of a plurality of triggering conditions, and wherein the plurality of triggering conditions comprises: (1) at least one of the one or more measurements on the one or more reflected first reference signals is below or above a corresponding threshold, (2) at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals is below or above a corresponding threshold, (3) at least one congestion metric associated with the one or more reflected first reference signals is below or above a corresponding threshold, (4) at least one priority associated with the one or more reflected first reference signals is below or above a corresponding threshold, (5) control information transmitted from the second node or a third node indicates triggering transmission of the one or more second reference signals, (6) at least one of the one or more first reference signals includes an indicator to trigger transmission of the one or more second reference signals, (7) a higher layer of the first node or the second node or the third node indicates triggering transmission of the one or more second reference signals, (8) the first node or the second node enters or leaves a specific geographical region or zone, (9) a speed of the first node or the second node is below or above a corresponding threshold, (10) a relative speed between the first node and the second node is below or above a corresponding threshold, (11) a separation distance between the first node and the second node is below or above a threshold, (12) at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (13) at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (14) at least one sensing characteristic for the one or more first reference signals does not meet a sensing requirement, (15) a change of at least one of a lighting condition or a weather condition associated with the node, (16) a confidence of the first sensing result is below or above a corresponding threshold, (17) an accuracy of the first sensing result is below or above a corresponding threshold, (18) at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type, and (19) at least one of the one or more objects detected by using the one or more first reference signals is a specific type of object.

[0436] Clause 226: The first node of clause 225, wherein the at least one congestion metric associated with the one or more reflected first reference signals comprises a channel busy ratio.

[0437] Clause 227: The first node of clause 225, wherein the at least one priority associated with the one or more reflected first reference signals comprises an L1 / L2 band priority, a proximity-based service per-packet priority (PPPP), 5G quality of service (QoS) identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority.

[0438] Clause 228: The first node of clause 225, wherein the control information transmitted from the second node is included in at least one of a physical layer signal or medium access control (MAC) layer information.

[0439] Clause 229: The first node of clause 225, wherein the higher layer comprises an application layer.

[0440] Clause 230: The first node of clause 225, wherein the specific geographical region or zone comprises one or more of: a highway, an urban scenario, a parking lot, an intersection, or a location associated with a pedestrian.

[0441] Clause 231: The first node of clause 225, wherein the specific geographical region or zone is configured, pre-configured, or pre-defined.

[0442] Clause 232: The first node of clause 225, wherein at least one mobility characteristic of the one or more objects comprises a location, a direction, or a velocity of at least one of the one or more objects.

[0443] Clause 233: The first node of clause 225, wherein at least one mobility characteristic change of the one or more objects comprises a location change, a direction change, or a velocity change of at least one of the one or more objects.

[0444] Clause 234: The first node of clause 225, wherein the at least one sensing characteristic for the one or more first reference signals comprises a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for at least one of the one or more first reference signals.

[0445] Clause 235: The first node of clause 225, wherein the specific node type comprises a vehicle, a base station, or a pedestrian.

[0446] Clause 236: The first node of clause 225, wherein the specific node type is configured, pre-configured, or pre-defined.

[0447] Clause 237: The first node of clause 225, wherein the specific type of object comprises a vehicle, a pedestrian, or an animal.

[0448] Clause 238: The first node of clause 225, wherein the specific type of object is configured, pre-configured, or pre-defined.

[0449] Clause 239: The first node of clause 225, wherein different triggering conditions among the plurality of triggering conditions trigger different second reference signals.

[0450] Clause 240: The first node of clause 216, wherein a first type of signals is used for the one or more first reference signals and a second type of signals is used for the one or more second reference signals.

[0451] Clause 241: The first node of clause 240, wherein the first type and the second type are different.

[0452] Clause 242: The first node of clause 240, wherein the first type and the second type are the same, and the one or more first reference signals use one or more parameters that are different from one or more parameters used for the one or more second reference signals.

[0453] Clause 243: The first node of clause 216, wherein the processor is configured to execute the instruction stored in the memory to: transmit one or more third reference signals, based on at least one of: a request for the one or more third reference signals, the first sensing result, or a second sensing result.

[0454] Clause 244: The first node of clause 243, wherein the one or more third reference signals are the same as, or different from, at least one of: the one or more first references signals, or the one or more second reference signals.

[0455] Clause 245: The first node of clause 243, wherein the processor is configured to execute the instruction stored in the memory to: transmit one or more fourth reference signals, based on at least one of: a request for the one or more fourth reference signals, the first sensing result, the second sensing result, or a third sensing result determined after transmission of the one or more third reference signals.

[0456] Clause 246: A second node for a communication, the second node comprising: a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: receive at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtain a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals received by the second node, or one or more measurements on the one or more reflected first reference signals received by the second node; and transmit, to the first node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or a first sensing result, for a determination of a decision on whether the one or more second reference signals need to be transmitted from the first node.

[0457] Clause 247: The second node of clause 246, wherein the processor is configured to execute the instruction stored in the memory to: receive at least one of: one or more second reference signals transmitted from the first node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtain a second sensing result based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals.

[0458] Clause 248: The second node of clause 247, wherein the processor is configured to execute the instruction stored in the memory to: obtain the second sensing result based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals, and at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on one or more reflected first reference signals.

[0459] Clause 249: The second node of clause 247, wherein the processor is configured to execute the instruction stored in the memory to: transmit, to the first node, at least one of: a request to transmit one or more third reference signals, the one or more measurements on the one or more second reference signals, the one or more measurements on the one or more reflected second reference signals, or the second sensing result, for a determination of a decision on whether the one or more third reference signals need to be transmitted from the first node.

[0460] Clause 250: The second node of clause 249, wherein the processor is configured to execute the instruction stored in the memory to: transmit, to the first node, at least one of: a request to transmit one or more fourth reference signals, one or more measurements on the one or more third reference signals, one or more measurements on the one or more reflected third reference signals, or a third sensing result, for a determination of a decision on whether the one or more fourth reference signals need to be transmitted from the first node.

[0461] Clause 251: A first node for a communication, the first node comprising: a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: transmit one or more first reference signals; receive at least one of: one or more second reference signals transmitted from a second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from one or more objects; and obtain a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals, wherein the one or more second reference signals are transmitted from the second node based on a decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0462] Clause 252: The first node of clause 251, wherein the one or more first reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0463] Clause 253: The first node of clause 251, wherein the processor is configured to execute the instruction stored in the memory to: determine, by the first node, the second sensing result based on processing of at least one of: the one or more measurements on the one or more second reference signals, or the one or more measurements on the one or more reflected second reference signals, and at least one of: a first sensing result of sensing the one or more objects, one or more measurements on the one or more first reference signals, or one or more measurements on one or more reflected first reference signals.

[0464] Clause 254: A second node for a communication, the second node comprising: a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: receive at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtain a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals, or one or more measurements on the one or more reflected first reference signals; obtain a decision on whether to transmit one or more second reference signals; and transmit the one or more second reference signals, based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0465] Clause 255: The second node of clause 254, wherein the one or more second reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0466] Clause 256: The second node of clause 254, wherein the processor is configured to execute the instruction stored in the memory to: receive, from the one or more objects, one or more reflected second reference signals that are formed by reflection of the one or more second reference signals from the one or more objects; and obtain a second sensing result based on processing of one or more measurements on the one or more reflected second reference signals.

[0467] Clause 257: The second node of clause 256, wherein the processor is configured to execute the instruction stored in the memory to: obtain the second sensing result based on processing of the one or more measurements on the one or more reflected second reference signals, and at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on the one or more reflected first reference signals.

[0468] Clause 258: The second node of clause 254, wherein the processor is configured to execute the instruction stored in the memory to: determine, by the second node, based on processing of at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on the one or more reflected first reference signals; or receive, from the first node or a third node, the decision made by the first node or the third node, the decision being made by the third node based on processing of information shared by the second node, the information comprising one or more measurements on at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on the one or more reflected first reference signals.

[0469] Clause 259: The second node of clause 254, wherein transmitting the one or more second reference signals is triggered by at least one of a plurality of triggering conditions, and wherein the plurality of triggering conditions comprises: (1) at least one of the one or more measurements on the one or more reflected first reference signals is below or above a corresponding threshold, (2) at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals is below or above a corresponding threshold, (3) at least one congestion metric associated with the one or more reflected first reference signals is below or above a corresponding threshold, (4) at least one priority associated with the one or more reflected first reference signals is below or above a corresponding threshold, (5) control information transmitted from the first node or a third node indicates triggering transmission of the one or more second reference signals, (6) at least one of the one or more first reference signals includes an indicator to trigger transmission of the one or more second reference signals, (7) a higher layer of the second node or the first node or the third node indicates triggering transmission of the one or more second reference signals, (8) the second node or the first node enters or leaves a specific geographical region or zone, (9) a speed of the second node or the first node is below or above a corresponding threshold, (10) a relative speed between the first node and the second node is below or above a corresponding threshold, (11) a separation distance between the first node and the second node is below or above a threshold, (12) at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (13) at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (14) at least one sensing characteristic for the one or more first reference signals does not meet a sensing requirement, (15) a change of at least one of a lighting condition or a weather condition associated with the node, (16) a confidence of the first sensing result is below or above a corresponding threshold, (17) an accuracy of the first sensing result is below or above a corresponding threshold, (18) at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type, and (19) at least one of the one or more objects detected by using the one or more first reference signals is a specific type of object.

[0470] Clause 260: The second node of clause 259, wherein the at least one congestion metric associated with the one or more reflected first reference signals comprises a channel busy ratio.

[0471] Clause 261: The second node of clause 259, wherein the at least one priority associated with the one or more reflected first reference signals comprises an L1 / L2 band priority, a proximity-based service per-packet priority (PPPP), 5G quality of service (QoS) identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority.

[0472] Clause 262: The second node of clause 259, wherein the control information transmitted from the second node is included in at least one of a physical layer signal or medium access control (MAC) layer information.

[0473] Clause 263: The second node of clause 259, wherein the higher layer of the second node comprises an application layer of the second node.

[0474] Clause 264: The second node of clause 259, wherein the specific geographical region or zone comprises one or more of: a highway, an urban scenario, a parking lot, an intersection, or a location associated with a pedestrian.

[0475] Clause 265: The second node of clause 259, wherein the specific geographical region or zone is configured, pre-configured, or pre-defined.

[0476] Clause 266: The second node of clause 259, wherein at least one mobility characteristic of the one or more objects comprises a location, a direction, or a velocity of at least one of the one or more objects.

[0477] Clause 267: The second node of clause 259, wherein at least one mobility characteristic change of the one or more objects comprises a location change, a direction change, or a velocity change of at least one of the one or more objects.

[0478] Clause 268: The second node of clause 259, wherein the at least one sensing characteristic for the one or more first reference signals comprises a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for at least one of the one or more first reference signals.

[0479] Clause 269: The second node of clause 259, wherein the specific node type comprises a vehicle, a base station, or a pedestrian.

[0480] Clause 270: The second node of clause 259, wherein the specific node type is configured, pre-configured, or pre-defined.

[0481] Clause 271: The second node of clause 259, wherein the specific type of object comprises a vehicle, a pedestrian, or an animal.

[0482] Clause 272: The second node of clause 259, wherein the specific type of object is configured, pre-configured, or pre-defined.

[0483] Clause 273: The second node of clause 259, wherein different triggering conditions among the plurality of triggering conditions trigger different second reference signals.

[0484] Clause 274: The second node of clause 254, wherein a first type of signals is used for the one or more first reference signals and a second type of signals is used for the one or more second reference signals.

[0485] Clause 275: The second node of clause 274, wherein the first type and the second type are different.

[0486] Clause 276: The second node of clause 274, wherein the first type and the second type are the same, and the one or more first reference signals use one or more parameters that are different from one or more parameters used for the one or more second reference signals.

[0487] Clause 277: The second node of clause 254, wherein the processor is configured to execute the instruction stored in the memory to: transmit one or more third reference signals, based on at least one of the first sensing result or a second sensing result.

[0488] Clause 278: The second node of clause 277, wherein the one or more third reference signals are the same as, or different from, at least one of: the one or more first references signals, or the one or more second reference signals.

[0489] Clause 279: The second node of clause 277, wherein the processor is configured to execute the instruction stored in the memory to: transmit one or more fourth reference signals, based on at least one of: the first sensing result, the second sensing result, or a third sensing result determined after transmission of the one or more third reference signals.

[0490] Clause 280: A second node for a communication, the second node comprising: a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: receive at least one of: one or more reference signals transmitted from a first node, or one or more reflected reference signals formed by reflection of the one or more reference signals from one or more objects; and obtain a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more reference signals, or one or more measurements on the one or more reflected reference signals, wherein the one or more reference signals are transmitted from a first node based on a decision indicating that the one or more reference signals need to be transmitted from the first node.

[0491] Clause 281: The second node of clause 280, wherein the one or more reference signals are one or more second reference signals and the sensing result is a second sensing result, and the processor is configured to execute the instruction stored in the memory to:: obtain the second sensing result based on processing of at least one of: the one or more measurements on the one or more reference signals, or the one or more measurements on the one or more reflected reference signals, and at least one of: a first sensing result, or one or more measurements on one or more reflected first reference signals.

[0492] Clause 282: A first node for a communication, the first node comprising: a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: transmit one or more first reference signals; receive, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtain a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; transmit, to a second node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result; receive at least one of: one or more second reference signals transmitted from the second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtain a second sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals.

[0493] Clause 283: The first node of clause 282, wherein the one or more first reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0494] Clause 284: The first node of clause 282, wherein the processor is configured to execute the instruction stored in the memory to: obtain the second sensing result based on processing of at least one of: the one or more measurements on the one or more second reference signals, or the one or more measurements on the one or more reflected second reference signals, and at least one of: the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0495] Clause 285: A second node for a communication, the second node comprising: a memory storing an instruction; and a processor configured to execute the instruction stored in the memory to: receive, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by one or more first reference signal transmitted from the first node and reflected from the one or more objects, or a first sensing result obtained based on the one or more measurements; obtain a decision on whether to transmit the one or more second reference signals; and transmit the one or more second reference signals based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0496] Clause 286: The second node of clause 285, wherein the one or more second reference signals comprise at least one of: one or more channel state information reference signals (CSI-RSs), one or more sounding reference signals (SRSs), one or more demodulation reference signals (DMRSs), one or more synchronization signals (SSs), one or more phase tracking reference signals (PT-RSs), one or more positioning reference signals (PRSs), or one or more integrated sensing and communication (ISAC) reference signals.

[0497] Clause 287: The second node of clause 285, wherein the one or more second reference signals are generated by adjusting one or more parameter values of the one or more first reference signals based on the first sensing result, wherein the one or more parameter values comprise at least one of: a carrier frequency, a bandwidth, a waveform, a beam width, a beam direction, or a transmission power.

[0498] Clause 288: The second node of clause 285, wherein the processor is configured to execute the instruction stored in the memory to: determine, by the second node, the decision based on at least one of: the request received from the first node, the one or more measurements, or the first sensing result; or receive, from the first node or a third node, the decision made by the first node or the third node, the decision being made by the third node based on processing of information shared by the first node, the information comprising at least one of: the one or more measurements on the one or more reflected first reference signals, or the first sensing result.

[0499] Clause 289: The second node of clause 285, wherein transmitting the one or more second reference signals is triggered by at least one of a plurality of triggering conditions, and wherein the plurality of triggering conditions comprises: (1) at least one of the one or more measurements on the one or more reflected first reference signals is below or above a corresponding threshold, (2) at least one ratio of a received path power to a reference received path power for the one or more reflected first reference signals is below or above a corresponding threshold, (3) at least one congestion metric associated with the one or more reflected first reference signals is below or above a corresponding threshold, (4) at least one priority associated with the one or more reflected first reference signals is below or above a corresponding threshold, (5) control information transmitted from the first node or the second node or a third node indicates triggering transmission of the one or more second reference signals, (6) at least one of the one or more first reference signals includes an indicator to trigger transmission of the one or more second reference signals, (7) a higher layer of the second node or the first node or the third node indicates triggering transmission of the one or more second reference signals, (8) the second node or the first node enters or leaves a specific geographical region or zone, (9) a speed of the second node or the first node is below or above a corresponding threshold, (10) a relative speed between the first node and the second node is below or above a corresponding threshold, (11) a separation distance between the first node and the second node is below or above a threshold, (12) at least one mobility characteristic of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (13) at least one mobility characteristic change of the one or more objects detected by using the one or more first reference signals is below or above a corresponding threshold, (14) at least one sensing characteristic for the one or more first reference signals does not meet a sensing requirement, (15) a change of at least one of a lighting condition or a weather condition associated with the node, (16) a confidence of the first sensing result is below or above a corresponding threshold, (17) an accuracy of the first sensing result is below or above a corresponding threshold, (18) at least one of a transmitter or a receiver of the one or more first reference signals is a specific node type, and (19) at least one of the one or more objects detected by using the one or more first reference signals is a specific type of object.

[0500] Clause 290: The second node of clause 289, wherein the at least one congestion metric associated with the one or more reflected first reference signals comprises a channel busy ratio.

[0501] Clause 291: The second node of clause 289, wherein the at least one priority associated with the one or more reflected first reference signals comprises an L1 / L2 band priority, a proximity-based service per-packet priority (PPPP), 5G quality of service (QoS) identifier (5QI) priority, a QoS class identifier (QCI) priority, or PC5 QoS identifier (PQI) priority.

[0502] Clause 292: The second node of clause 289, wherein the control information transmitted from the second node is included in at least one of a physical layer signal or medium access control (MAC) layer information.

[0503] Clause 293: The second node of clause 289, wherein the higher layer of the second node comprises an application layer of the second node.

[0504] Clause 294: The second node of clause 289, wherein the specific geographical region or zone comprises one or more of: a highway, an urban scenario, a parking lot, an intersection, or a location associated with a pedestrian.

[0505] Clause 295: The second node of clause 289, wherein the specific geographical region or zone is configured, pre-configured, or pre-defined.

[0506] Clause 296: The second node of clause 289, wherein at least one mobility characteristic of the one or more objects comprises a location, a direction, or a velocity of at least one of the one or more objects.

[0507] Clause 297: The second node of clause 289, wherein at least one mobility characteristic change of the one or more objects comprises a location change, a direction change, or a velocity change of at least one of the one or more objects.

[0508] Clause 298: The second node of clause 289, wherein the at least one sensing characteristic for the one or more first reference signals comprises a range resolution, a maximum unambiguous range, a velocity resolution, a maximum unambiguous velocity, an angular resolution, or a maximum field of view for at least one of the one or more first reference signals.

[0509] Clause 299: The second node of clause 289, wherein the specific node type comprises a vehicle, a base station, or a pedestrian.

[0510] Clause 300: The second node of clause 289, wherein the specific node type is configured, pre-configured, or pre-defined.

[0511] Clause 301: The second node of clause 289, wherein the specific type of object comprises a vehicle, a pedestrian, or an animal.

[0512] Clause 302: The second node of clause 289, wherein the specific type of object is configured, pre-configured, or pre-defined.

[0513] Clause 303: The second node of clause 289, wherein different triggering conditions among the plurality of triggering conditions trigger different second reference signals.

[0514] Clause 304: The second node of clause 285, wherein the processor is configured to execute the instruction stored in the memory to: transmit one or more third reference signals, based on at least one of the first sensing result or a second sensing result obtained based on one or more measurements on the one or more second reference signals.

[0515] Clause 305: The second node of clause 304, wherein the one or more third reference signals are the same as, or different from, at least one of: the one or more first references signals, or the one or more second reference signals.

[0516] Clause 306: The second node of clause 304, wherein the processor is configured to execute the instruction stored in the memory to: transmit one or more fourth reference signals, based on at least one of: the first sensing result, the second sensing result, or a third sensing result determined after transmission of the one or more third reference signals.

[0517] Clause 307: A non-transitory computer-readable medium storing instructions that are executable by one or more processors of a node for a communication, to perform a method, the method comprising: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; obtaining a decision on whether to transmit one or more second reference signals, the decision being made based on the first sensing result; and transmitting the one or more second reference signals, based on the decision.

[0518] Clause 308: A non-transitory computer-readable medium storing instructions that are executable by one or more processors of a first node for a communication, to perform a method, the method comprising: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; and transmitting, to a second node, at least one of: a request to transmit one or more second reference signals to the one or more objects, the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

[0519] Clause 309: A non-transitory computer-readable medium storing instructions that are executable by one or more processors of a second node for a communication, to perform a method, the method comprising: receiving, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by reflection of one or more first reference signals from one or more objects, or a first sensing result of sensing the one or more objects based on processing of the one or more measurements; obtaining a decision on whether to transmit the one or more second reference signals to the one or more objects; transmitting the one or more second reference signals, based on the decision; receiving, from the one or more objects, one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected second reference signals.

[0520] Clause 310: A non-transitory computer-readable medium storing instructions that are executable by one or more processors of a first node for a communication, to perform a method, the method comprising: transmitting one or more first reference signals; receiving, from a second node, at least one of: a request to transmit one or more second reference signals, one or more measurements on the one or more first reference signals, one or more measurements on one or more reflected first reference signals received by the second node, or a first sensing result of sensing one or more objects, wherein the one or more reflected first reference signals are formed by reflection of the one or more first reference signals from the one or more objects; and obtaining a decision on whether to transmit the one or more second reference signals.

[0521] Clause 311: A non-transitory computer-readable medium storing instructions that are executable by one or more processors of a second node for a communication, to perform a method, the method comprising: receiving at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals received by the second node, or one or more measurements on the one or more reflected first reference signals received by the second node; and transmitting, to the first node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or a first sensing result, for a determination of a decision on whether the one or more second reference signals need to be transmitted from the first node.

[0522] Clause 312: A non-transitory computer-readable medium storing instructions that are executable by one or more processors of a first node for a communication, to perform a method, the method comprising: transmitting one or more first reference signals; receiving at least one of: one or more second reference signals transmitted from a second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from one or more objects; and obtaining a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals, wherein the one or more second reference signals are transmitted from the second node based on a decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0523] Clause 313: A non-transitory computer-readable medium storing instructions that are executable by one or more processors of a second node for a communication, to perform a method, the method comprising: receiving at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals, or one or more measurements on the one or more reflected first reference signals; obtaining a decision on whether to transmit one or more second reference signals; and transmitting the one or more second reference signals, based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

[0524] Clause 314: A non-transitory computer-readable medium storing instructions that are executable by one or more processors of a second node for a communication, to perform a method, the method comprising: receiving at least one of: one or more reference signals transmitted from a first node, or one or more reflected reference signals formed by reflection of the one or more reference signals from one or more objects; and obtaining a sensing result of sensing the one or more objects b...

Claims

1. A method for a node for a communication, the method comprising: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; obtaining a decision on whether to transmit one or more second reference signals, the decision being made based on the first sensing result; and transmitting the one or more second reference signals, based on the decision.

2. The method of claim 1, wherein the node is a first node, and wherein obtaining the first sensing result comprises at least one of: determining, by the first node, the first sensing result based on the processing of the one or more measurements on the one or more reflected first reference signals; or receiving, from a second node, the first sensing result determined by the second node, the first sensing result being determined by the second node based on the one or more measurements on the one or more reflected first reference signals provided by the first node.

3. The method of claim 1, wherein the node is a first node, and wherein obtaining the decision comprises at least one of: determining, by the first node and based on the first sensing result, whether to transmit the one or more second reference signals; or receiving, from a second node, the decision made by the second node, the decision being made by the second node based on information provided by the first node, the information comprising at least one of: the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

4. A method for a first node for a communication, the method comprising: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; and transmitting, to a second node, at least one of: a request to transmit one or more second reference signals to the one or more objects, the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

5. The method of claim 4, wherein obtaining the first sensing result further comprises at least one of: determining, by the first node, the first sensing result based on processing of the one or more measurements on the one or more reflected first reference signals; or receiving, from the second node or a third node, the first sensing result determined by the second node or the third node based on processing of the one or more measurements on the one or more reflected first reference signals, the one or more measurements on the one or more reflected first reference signals being provided to the second node or the third node by the first node.

6. A method for a second node for a communication, the method comprising: receiving, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by reflection of one or more first reference signals from one or more objects, or a first sensing result of sensing the one or more objects based on processing of the one or more measurements; obtaining a decision on whether to transmit the one or more second reference signals to the one or more objects; transmitting the one or more second reference signals, based on the decision; receiving, from the one or more objects, one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected second reference signals.

7. The method of claim 6, wherein obtaining the decision further comprises at least one of: determining, by the second node, the decision based on at least one of: the request received from the first node, the one or more measurements on the one or more reflected first reference signals received from the first node, or the first sensing result determined by the first node; or receiving, from the first node or a third node, the decision made by the first node or the third node, the decision being made by the third node based on processing of information shared by the first node, the information comprising at least one of: the first sensing result, or the one or more measurements on the one or more reflected first reference signals.

8. A method for a first node for a communication, the method comprising: transmitting one or more first reference signals; receiving, from a second node, at least one of: a request to transmit one or more second reference signals, one or more measurements on the one or more first reference signals, one or more measurements on one or more reflected first reference signals received by the second node, or a first sensing result of sensing one or more objects, wherein the one or more reflected first reference signals are formed by reflection of the one or more first reference signals from the one or more objects; and obtaining a decision on whether to transmit the one or more second reference signals.

9. The method of claim 8, further comprising: transmitting, to the one or more objects, the one or more second reference signals, based on the decision indicating that the one or more second reference signals need to be transmitted from the first node; receiving one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected second reference signals.

10. The method of claim 8, wherein obtaining the decision comprises at least one of: determining, by the first node, the decision based on at least one of: the request received from the second node, the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result; or receiving, from the second node or a third node, the decision made by the second node or the third node, the decision being made by the third node based on processing of information shared by the second node, the information comprising at least one of: the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result.

11. A method for a second node for a communication, the method comprising: receiving at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals received by the second node, or one or more measurements on the one or more reflected first reference signals received by the second node; and transmitting, to the first node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more first reference signals, the one or more measurements on the one or more reflected first reference signals, or a first sensing result, for a determination of a decision on whether the one or more second reference signals need to be transmitted from the first node.

12. The method of claim 11, further comprising: receiving at least one of: one or more second reference signals transmitted from the first node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals.

13. A method for a first node for a communication, the method comprising: transmitting one or more first reference signals; receiving at least one of: one or more second reference signals transmitted from a second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from one or more objects; and obtaining a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals, wherein the one or more second reference signals are transmitted from the second node based on a decision indicating that the one or more second reference signals need to be transmitted from the second node.

14. The method of claim 13, wherein the sensing result is a second sensing result, and obtaining the second sensing result further comprises: determining, by the first node, the second sensing result based on processing of at least one of: the one or more measurements on the one or more second reference signals, or the one or more measurements on the one or more reflected second reference signals, and at least one of: a first sensing result of sensing the one or more objects, one or more measurements on the one or more first reference signals, or one more measurements on one or more reflected first reference signals.

15. A method for a second node for a communication, the method comprising: receiving at least one of: one or more first reference signals transmitted from a first node, or one or more reflected first reference signals formed by reflection of the one or more first reference signals from one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more first reference signals, or one or more measurements on the one or more reflected first reference signals; obtaining a decision on whether to transmit one or more second reference signals; and transmitting the one or more second reference signals, based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

16. The method of claim 15, further comprising: receiving, from the one or more objects, one or more reflected second reference signals that are formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result based on processing of one or more measurements on the one or more reflected second reference signals.

17. The method of claim 16, wherein obtaining the decision comprises at least one of: determining, by the second node, based on processing of at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on the one or more reflected first reference signals; or receiving, from the first node or a third node, the decision made by the first node or the third node, the decision being made by the third node based on processing of information shared by the second node, the information comprising one or more measurements on at least one of: the first sensing result, the one or more measurements on the one or more first reference signals, or the one or more measurements on the one or more reflected first reference signals.

18. A method for a second node for a communication, the method comprising: receiving at least one of: one or more reference signals transmitted from a first node, or one or more reflected reference signals formed by reflection of the one or more reference signals from one or more objects; and obtaining a sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more reference signals, or one or more measurements on the one or more reflected reference signals, wherein the one or more reference signals are transmitted from a first node based on a decision indicating that the one or more reference signals need to be transmitted from the first node.

19. A method for a first node for a communication, the method comprising: transmitting one or more first reference signals; receiving, from one or more objects, one or more reflected first reference signals formed by reflection of the one or more first reference signals from the one or more objects; obtaining a first sensing result of sensing the one or more objects based on processing of one or more measurements on the one or more reflected first reference signals; transmitting, to a second node, at least one of: a request to transmit one or more second reference signals, the one or more measurements on the one or more reflected first reference signals, or the first sensing result; receiving at least one of: one or more second reference signals transmitted from the second node, or one or more reflected second reference signals formed by reflection of the one or more second reference signals from the one or more objects; and obtaining a second sensing result of sensing the one or more objects based on processing of at least one of: one or more measurements on the one or more second reference signals, or one or more measurements on the one or more reflected second reference signals.

20. A method for a second node for a communication, the method comprising: receiving, from a first node, at least one of: a request to transmit one or more second reference signals, one or more measurements on one or more reflected first reference signals that are formed by one or more first reference signal transmitted from the first node and reflected from the one or more objects, or a first sensing result obtained based on the one or more measurements; obtaining a decision on whether to transmit the one or more second reference signals; and transmitting the one or more second reference signals based on the decision indicating that the one or more second reference signals need to be transmitted from the second node.

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