Power consumption optimization ranging method and apparatus for wireless communication devices

Abstract

The application discloses a power consumption optimization ranging method and device for a wireless communication device, comprising: receiving a ranging request from a host system to determine the distance between the wireless communication device and a target access point (AP); determining whether the ranging mode is an energy-saving ranging mode; in response to the ranging request and determining that the ranging mode is the energy-saving ranging mode, determining whether the displacement of the wireless communication device exceeds a preset displacement threshold; if the displacement does not exceed the preset displacement threshold, generating a ranging result indicating the distance based on historical ranging results related to the target AP, and avoiding sending a ranging data packet to the target AP; and if the displacement exceeds the preset displacement threshold, performing a ranging operation with the target AP to generate the ranging result.

Description

Technical Field

[0001] This invention relates to ranging methods, and more specifically, to a power-optimized ranging method and apparatus for wireless communication devices. Background Technology

[0002] This invention relates to wireless communication systems, and more particularly to a power-optimized ranging method and apparatus for device positioning.

[0003] Location-based services (LBS) have become an indispensable part of modern mobile applications, covering areas such as indoor navigation, asset tracking, geofencing, and proximity marketing. While global navigation satellite systems (GNSS) function well in outdoor environments, their signals are often attenuated or blocked indoors. Therefore, indoor positioning solutions based on existing wireless infrastructure (such as Wi-Fi) are widely deployed for indoor positioning.

[0004] Early Wi-Fi positioning methods primarily relied on Received Signal Strength Indicator (RSSI) fingerprinting. While RSSI-based positioning offers power efficiency advantages, significant fluctuations in RSSI signals due to multipath fading and environmental obstruction typically result in low positioning accuracy, with errors ranging from several meters (e.g., approximately 5 to 10 meters). To improve positioning accuracy, IEEE 802.11 introduced round-trip time (RTT) based ranging mechanisms, such as the fine timing measurement (FTM) specified in IEEE 802.11mc (Wi-Fi RTT), and subsequent revisions (such as IEEE 802.11az) further enhanced ranging performance. This type of ranging process estimates the distance between a wireless communication device (e.g., a smartphone) and an access point (AP) through timing measurements obtained by exchanging dedicated measurement data packets.

[0005] However, improved ranging accuracy may lead to increased power consumption. Unlike passive RSSI monitoring, RTT-based ranging typically requires the wireless connectivity subsystem to initiate active measurement exchanges (e.g., FTM exchanges) with the access point. To mitigate the effects of noise and multipath effects, ranging results may require multiple measurement packet exchanges within a single packet burst. Furthermore, to estimate two-dimensional position using trilateration, the host system typically uses ranging results from at least three different access points within the positioning period.

[0006] In continuous tracking scenarios (such as indoor navigation), the main processor may repeatedly issue ranging requests to update the device's position estimate. Traditional implementations may perform active measurement exchanges on each request, regardless of whether the device is stationary or undergoing only limited movement. Frequent ranging data packet transmission and reception can place a significant burden on battery-powered devices. Therefore, there is an urgent need for technologies that intelligently manage ranging operations to reduce power consumption while maintaining positioning performance and continuity. Summary of the Invention

[0007] In view of this, one object of the present invention is to provide a method and apparatus for power-optimized Wi-Fi ranging, which can reduce unnecessary active ranging operations while maintaining location continuity for location-based services. In some embodiments, the ranging device receives a ranging request from a host system and determines whether the ranging request should be processed in an energy-saving ranging mode. In energy-saving ranging mode, the ranging device performs a displacement detection operation to assess whether the displacement of the wireless communication device is within an acceptable range. This displacement detection operation may be based on one or more signal strength indicators of the target access point (AP) and / or motion data from an inertial measurement unit. If the displacement does not exceed a preset displacement threshold, the ranging device will avoid initiating a new ranging operation with the target AP and instead generate a current ranging result based on historical ranging results. If the estimated displacement exceeds the displacement threshold, the ranging device will initiate an active ranging operation with the target AP to generate a new ranging result.

[0008] Furthermore, even when performing new ranging operations, the ranging device can adjust its ranging parameters according to the ranging mode. For example, in energy-saving ranging mode, a reduced number of ranging data packets / frames are used for each burst, while in accuracy-optimized ranging mode, the full number of ranging data packets / frames are used for a complete ranging configuration. By suppressing active ranging operations when displacement is limited and customizing ranging overhead when ranging operations are required, this invention effectively reduces the airtime and power consumption of the ranging device, thereby extending the device's battery life in continuous position tracking scenarios, while providing timely per-AP ranging results that can be used for device positioning.

[0009] According to one embodiment, a power-optimized ranging method for a wireless communication device is provided. The method includes: receiving a ranging request from a host system to determine the distance between the wireless communication device and a target access point (AP); determining whether the ranging mode corresponding to the ranging request is an energy-saving ranging mode; responding to the ranging request and determining that the ranging mode is the energy-saving ranging mode, determining whether the displacement of the wireless communication device exceeds a preset displacement threshold; if the displacement does not exceed the preset displacement threshold, generating a ranging result indicating the distance based on historical ranging results associated with the target AP, and avoiding sending ranging data packets to the target AP; if the displacement exceeds the preset displacement threshold, performing a ranging operation with the target AP to generate the ranging result.

[0010] According to one embodiment, a ranging device is provided. The ranging device includes a processor and a memory. The memory stores instructions that, when executed by the processor, enable the ranging device to: receive a ranging request from a host system to determine the distance between a wireless communication device and a target access point (AP); determine whether the ranging mode corresponding to the ranging request is an energy-saving ranging mode; in response to the ranging request and determining that the ranging mode is the energy-saving ranging mode, determine whether the displacement of the wireless communication device exceeds a preset displacement threshold; if the displacement does not exceed the preset displacement threshold, generate a ranging result indicating the distance based on historical ranging results associated with the target AP, and avoid sending ranging data packets to the target AP; if the displacement exceeds the preset displacement threshold, perform a ranging operation with the target AP to generate the ranging result.

[0011] These and other objects of the present invention will undoubtedly become apparent to those skilled in the art upon reading the following detailed description of the preferred embodiments and the accompanying drawings. Attached Figure Description

[0012] Figure 1 The diagram illustrates the implementation of the power-optimized ranging method of the present invention in an example wireless communication environment.

[0013] Figure 2 This is a schematic diagram illustrating a wireless communication device according to an embodiment of the present invention.

[0014] Figure 3 The flowchart illustrates a power optimization method for power-optimized ranging operations according to an embodiment of the present invention.

[0015] Figure 4 To simplify the flowchart, a power-optimized ranging method according to an embodiment of the present invention will be described. Detailed Implementation

[0016] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the embodiments. However, those skilled in the art will understand that these specific details are not necessary to practice the embodiments. In other instances, well-known materials or methods have not been described in detail to avoid obscuring the embodiments.

[0017] References to "an embodiment" or "one embodiment" in this specification mean that a particular feature, structure, or characteristic described in connection with that embodiment or example is included in at least one embodiment of this embodiment. Therefore, "in one embodiment" or "in one embodiment" appearing throughout this specification do not necessarily refer to the same embodiment. Furthermore, specific features, structures, or characteristics may be combined in any suitable combination and / or sub-combination in one or more embodiments.

[0018] Figure 1 This is a schematic diagram illustrating a typical wireless communication environment in which the power-optimized ranging method and apparatus of the present invention can be implemented. As shown, a typical wireless communication environment includes a wireless communication device 100 located in a location served by multiple access points (APs) 200_1-200_n.

[0019] The wireless communication device 100 can be any electronic device capable of wireless connectivity. According to various embodiments of the present invention, the wireless communication device 100 is not limited thereto, and may also include smartphones, tablets, laptops, wearable devices, portable devices, Internet of Things (IoT) devices, or autonomous mobile robots.

[0020] The primary configuration of APs 200_1-200_n is to provide wireless network connectivity for wireless communication device 100, bridging the wireless medium with a backbone network (e.g., a local area network (LAN) or a wide area network (WAN)). Wireless communication device 100 typically associates with one or more APs 200_1-200_n to exchange user data. APs 200_1-200_n can be arranged in various network topologies. In some embodiments, APs 200_1-200_n are deployed as corresponding basic service sets (BSS) and interconnected through a distributed system to form extended service sets (ESS). In some embodiments, APs 200_1-200_n can form a wireless lattice network, in which at least some APs can communicate with each other.

[0021] In addition to data transmission, APs 200_1-200_n can also support location-based services (LBS) related positioning functions. Specifically, APs 200_1-200_n can serve as anchor points for indoor positioning based on known locations. Wireless communication device 100 can perform Wi-Fi ranging (distance measurement based on round-trip time (RTT) or time-of-flight (TOF)) with APs 200_1-200_n according to the IEEE 802.11 standard, for example using IEEE 802.11mc fine timing measurement (FTM) and / or IEEE 802.11az null packet (NDP) ranging procedures. APs 200_1-200_n do not need to be in the same management domain; in some embodiments, wireless communication device 100 can perform ranging on neighboring APs associated with different networks, provided that these APs support and allow participation in the ranging procedure.

[0022] To perform positioning, wireless communication device 100 initiates ranging operations with multiple access points (APs) among APs 200_1-200_n. It should be noted that the set of APs used for ranging may differ from the serving AP used by wireless communication device 100 for data transmission. To resolve two-dimensional location via trilateration or polygonal measurement, wireless communication device 100 needs to perform ranging operations with at least three APs among APs 200_1-200_n.

[0023] Ranging is performed to derive the distance based on the RTT (Round-Trip Time) of data packets / frames exchanged between wireless communication device 100 and AP 200_1-200_n. For example... Figure 1 As shown, the wireless communication device 100 can obtain the distance d1 to the currently associated serving AP 200_1, and also obtain the distances d2 and d3 to the neighboring non-serving APs 200_2 and 200_3.

[0024] To achieve high-precision ranging, the ranging operation may require the wireless communication device 100 to transmit and receive multiple ranging data packets / frames. For example, a single ranging result may require approximately six pairs of burst exchanges of transmit and receive data packets with the target AP. This transmission behavior poses a challenge to power consumption, especially when the wireless communication device 100 frequently performs ranging for continuous position tracking.

[0025] Figure 2A schematic diagram of a wireless communication device 100 according to an embodiment of the present invention is shown. The wireless communication device 100 includes a host system 101 (further including a host / application processor 201) and a ranging device 102 coupled to the host system 101. The host processor 201 can execute an operating system and one or more location-related applications. The ranging device 102 may be included in a wireless connectivity subsystem 103, wherein the wireless connectivity subsystem 103 can be implemented as a standalone Wi-Fi chipset or as a connectivity core integrated within a system-on-chip (SoC). In some embodiments, the ranging device 102 may further include a processor 202 (which may be an embedded microcontroller and / or a digital signal processor (DSP)) equipped with local memory 203 for executing firmware instructions to implement the power-optimized ranging method described herein. Furthermore, the ranging device 102 can output per-AP ranging results associated with at least three APs (APs) from AP 200_1 to 200_n) to the host system 101. Therefore, the host system 101 can calculate the location of the wireless communication device 100 based on these per-AP ranging results through trilateration.

[0026] Figure 3 A flowchart of a power-optimized ranging method according to an embodiment of the present invention is shown.

[0027] In step S101, the process begins with the ranging device 102 receiving a ranging request from the host system 101. This ranging request may be generated by a location-related application (e.g., an indoor positioning application) running on the host system 101 to request the ranging result for each AP corresponding to a set of target APs (e.g., AP 200_1-200_3).

[0028] In step S102, in response to receiving a ranging request, the ranging device 102 determines the current ranging mode. Specifically, the ranging device 102 can determine whether it is configured to operate in an energy-saving ranging mode or an accuracy-priority ranging mode.

[0029] If the ranging device 102 is configured in accuracy-priority ranging mode, the process can continue to execute standard ranging operations (such as IEEE 802.11mc FTM switching and / or IEEE 802.11az ranging procedures) related to the target AP (e.g., one of AP 200_1-200_3) to obtain ranging results related to the target AP, ensuring accurate distance estimation between the wireless communication device 100 and the target AP. If the ranging device 102 is configured in energy-saving ranging mode, the process proceeds to step S103 to perform a displacement check operation.

[0030] In step S103, the ranging device 102 performs a displacement check operation to determine whether previously generated / historical ranging results related to the target AP are still valid, wherein the previously generated / historical ranging results are recorded in the ranging device 102. During the displacement check operation, the ranging device 102 evaluates whether the estimated displacement of the wireless communication device 100 exceeds a preset displacement threshold. When the estimated displacement does not exceed the preset displacement threshold, the ranging device 102 does not initiate a new ranging operation related to the target AP. Instead, the ranging device 102 generates a ranging result for the host system 101 based on the previously generated / historical ranging results related to the target AP (step S104). When the estimated displacement exceeds the preset displacement threshold, the ranging device 102 continues to initiate a new ranging operation related to the target AP (step S105), generating a new ranging result for the host system 101.

[0031] In one embodiment, the displacement check operation in step S103 is based on the change in the received signal strength indicator (RSSI) measurement associated with the target AP. For example, the ranging device 102 determines whether the RSSI change between the current RSSI value and the previous RSSI value is within a preset tolerance range. In one example, the preset tolerance is 5 dBm. If the RSSI change is within the preset tolerance range, the ranging device 102 determines that the displacement of the wireless communication device 100 does not exceed a preset displacement threshold and reuses the previously generated / historical ranging result associated with the target AP (step S104). If the RSSI change exceeds the preset tolerance range, the ranging device 102 determines that the displacement of the wireless communication device 100 exceeds the preset displacement threshold and initiates a new ranging operation to obtain a new ranging result (step S105).

[0032] In one embodiment, the ranging device 102 further determines whether the previous RSSI value is outdated. For example, the ranging device 102 determines the time difference between the timestamp associated with the previous RSSI value and the current time. If the time difference exceeds the staleness threshold, the ranging device 102 determines that the RSSI change is unreliable and initiates a new ranging operation associated with the target AP (step S105).

[0033] In one embodiment, the displacement determination step S103 is based on motion sensor data. For example, the ranging device 102 acquires motion data from one or more inertial measurement units (IMUs), such as accelerometers and / or gyroscopes, within the wireless communication device 100, and estimates the displacement (or motion state) of the wireless communication device 100 at time intervals. If the estimated displacement exceeds a preset displacement threshold (or the motion state indicates significant movement), the ranging device 102 initiates a new ranging operation related to the target AP (step S105); otherwise, the ranging device 102 reuses previously generated / historical ranging results related to the target AP (step S104).

[0034] In one embodiment, the displacement determination step S103 is performed by referencing RSSI changes and motion data from one or more IMUs. The ranging device 102 can determine whether the estimated displacement exceeds a preset displacement threshold based on a decision derived jointly from the RSSI changes and motion data. For example, if (a) the RSSI change is within a preset tolerance range and (b) the displacement estimated based on the motion data does not exceed the displacement threshold (or the motion state indicates a stationary or low-motion state), the ranging device 102 determines that the previously generated / historical ranging results are still valid; otherwise, the ranging device 102 initiates a new ranging operation related to the target AP to obtain new ranging results (step S105).

[0035] In some embodiments, acquiring the RSSI value associated with a target AP does not require initiating an active scan or sending a probe request. Instead, ranging device 102 may include an RSSI processing engine 204. The RSSI processing engine 204 may be dedicated hardware and configured to acquire RSSI values ​​from received IEEE 802.11 beacon frames or management frames. The RSSI processing engine 204 may passively monitor beacon frames from neighboring APs (including APs not serving wireless communication device 100) during periodic listening intervals and may store one or more RSSI values ​​for later access. For example, the RSSI processing engine may acquire RSSI values ​​from: (i) beacon frames sent by serving APs associated with wireless communication device 100 (such as beacons corresponding to Flow Indication Message (DTIM) information) and / or (ii) beacon frames sent by neighboring non-serving APs (such as APs in an Overlapping Basic Service Set (OBSS)). Therefore, when performing displacement determination operations, the ranging device 102 can directly retrieve the stored RSSI value from the RSSI processing engine 204, thereby reducing or avoiding additional transmission operations and overhead associated with active scanning.

[0036] When the estimated displacement of the wireless communication device 100 does not exceed a preset displacement threshold, the process proceeds to step S104. In step S104, the ranging device 102 avoids initiating new ranging operations with the target AP, for example, avoiding sending ranging data packets / frames to the target AP. Instead, the ranging device 102 generates a current ranging result based on historical / previously generated ranging results associated with the target AP. In some embodiments, the ranging device 102 selects the latest ranging result associated with the target AP as the current ranging result and outputs it to the host system 101. In other embodiments, the ranging device 102 performs statistical estimation based on one or more historical / previously generated ranging results associated with the target AP (through averaging, weighted averaging, or other histogram-based algorithms) to generate the current ranging result. By avoiding additional ranging operations when the displacement is within an acceptable range, the ranging device 102 reduces airtime and power consumption while still satisfying the ranging request of the host system 101.

[0037] Furthermore, even if it is deemed necessary to initiate a new ranging operation, the ranging device 102 can apply secondary energy-saving technology by adjusting the measurement parameters. In step S106, the ranging device 102 determines whether the current ranging mode is an energy-saving ranging mode or an accuracy-priority ranging mode, and selects the corresponding ranging configuration accordingly.

[0038] If the ranging device 102 is configured in energy-saving ranging mode, it performs ranging operations with a non-complete ranging configuration (step S107). For example, the ranging device 102 uses a reduced number of ranging data packets / frames (including sent and received data packets / frames) to perform ranging operations in each burst, thereby saving power consumption. If the ranging device 102 is configured in accuracy-priority ranging mode, it performs ranging operations with a complete ranging configuration (step S108). For example, the ranging device 102 uses a full number (greater than the number in the non-complete ranging configuration) of ranging data packets / frames (including sent and received data packets / frames) to perform ranging operations in each burst, thereby improving ranging accuracy.

[0039] Figure 4 A simplified flowchart illustrating a power-optimized ranging method according to an embodiment of the present invention is shown. As illustrated, the method includes the following steps: Step S201: Receive a ranging request from the host system to determine the distance between the wireless communication device and the target access point (AP); Step S202: Determine whether the ranging mode corresponding to the ranging request is the energy-saving ranging mode; Step S203: In response to the ranging request and determining that the ranging mode is the energy-saving ranging mode, determine whether the displacement of the wireless communication device exceeds the preset displacement threshold. Step S204: If it is determined that the displacement does not exceed the preset displacement threshold, then a ranging result indicating the distance is generated based on the historical ranging results related to the target AP, and ranging data packets are avoided from being sent to the target AP; Step S205: If it is determined that the displacement exceeds the preset displacement threshold, then a ranging operation is performed with the target AP to generate the ranging result.

[0040] Since the principles and specific details of the above steps have been clearly described in the foregoing embodiments, they will not be repeated here. It should be noted that the above process can be improved by adding other additional steps or making appropriate modifications and / or adjustments to achieve better ranging and positioning performance and accuracy.

[0041] In summary, the ranging method and apparatus of the present invention can intelligently suppress unnecessary Wi-Fi ranging operations and adaptively reduce measurement overhead based on device displacement and ranging mode, thereby reducing airtime and power consumption while maintaining reliable ranging results to support continuous indoor positioning and other location-based services.

[0042] According to this embodiment, the implementation can be carried out as an apparatus, method, or computer program product. Therefore, this embodiment can be implemented entirely in hardware, entirely in software, or in a combination of software and hardware aspects, all of which can be collectively referred to as a "module" or "system." Furthermore, this embodiment can take the form of a computer program product carrying computer-usable program code on any expressible tangible medium. In terms of hardware, the present invention can be implemented by applying any of the following technologies or related combinations: individual operating logic having logic gates capable of performing logical functions based on data signals, and applying application-specific integrated circuits (ASICs), programmable gate arrays (PGAs), or field-programmable gate arrays (FPGAs) and suitable combinations thereof.

[0043] Flowcharts and block diagrams within flowcharts illustrate the architecture, functionality, and operation of systems, methods, and computer program products according to this embodiment. In this regard, each module in a flowchart or block diagram may represent a module, segment, or code portion, containing one or more executable instructions for implementing a specified logical function. It should also be noted that each module and combination thereof in the block diagrams and / or flowcharts may be implemented with a specified function or action by a dedicated hardware system, or by a combination of dedicated hardware and computer instructions. These computer program instructions may be stored in a computer-readable medium, instructing a computer or other programmable data processing apparatus to operate in a particular manner, causing the instructions stored in the computer-readable medium to produce an article of manufacture containing means of instruction to implement the specified functions / actions in the flowcharts and / or block diagrams.

[0044] The foregoing summary outlines the features of various embodiments, enabling those skilled in the art to fully understand various aspects of this disclosure. Those skilled in the art should recognize that this disclosure provides a basis for designing or modifying other processes and structures to achieve substantially the same functionality and / or substantially the same results as the embodiments described herein. Furthermore, such equivalent solutions do not depart from the spirit and scope of this disclosure, and various changes, substitutions, and modifications can be made without departing from this disclosure.

Claims

1. A power-optimized ranging method for wireless communication devices, comprising: Receive a ranging request from the host system to determine the distance between the wireless communication device and the target access point (AP); Determine whether the ranging mode corresponding to the ranging request is the energy-saving ranging mode; In response to the ranging request and after determining that the ranging mode is the energy-saving ranging mode, it is determined whether the displacement of the wireless communication device exceeds a preset displacement threshold. If it is determined that the displacement does not exceed the preset displacement threshold, then based on the historical ranging results related to the target AP, a ranging result indicating the distance is generated, and ranging data packets are avoided from being sent to the target AP. If the displacement is determined to exceed the preset displacement threshold, a ranging operation is performed with the target AP to generate the ranging result.

2. The ranging method as described in claim 1, wherein the step of determining whether the displacement of the wireless communication device exceeds a preset displacement threshold includes: Determine whether the Received Signal Strength Indicator (RSSI) change associated with the target AP is within a preset tolerance range; If the RSSI change is within the preset tolerance range, it is determined that the displacement of the wireless communication device has not exceeded the preset displacement threshold.

3. The ranging method as described in claim 2, wherein the step of determining whether the displacement of the wireless communication device exceeds a preset displacement threshold further includes: Determine the time difference between the current time and the timestamp associated with the previous RSSI value used to calculate this RSSI change; If the time difference exceeds the stale threshold, the RSSI change is deemed unreliable, and the ranging operation is performed with the target AP to generate the ranging result.

4. The ranging method as described in claim 2, further comprising: By passively receiving one or more beacon frames, at least one RSSI value associated with the target AP is obtained without initiating active scanning or sending a probe request, wherein the one or more beacon frames include beacon frames sent by a serving AP associated with the wireless communication device and / or beacon frames sent by one or more neighboring non-serving APs in an Overlapping Basic Service Set (OBSS). The at least one RSSI value is extracted from one or more passively received beacon frames.

5. The ranging method as described in claim 1, wherein the step of determining whether the displacement of the wireless communication device exceeds a preset displacement threshold includes: Motion data is acquired from one or more inertial sensors within the wireless communication device; The displacement of the wireless communication device is estimated based on this motion data; Based on the estimated displacement and / or the motion state indicated by the motion data, it is determined whether the displacement of the wireless communication device exceeds the preset displacement.

6. The ranging method of claim 1, wherein the step of generating a ranging result indicating the distance based on historical ranging results associated with the target AP includes at least one of the following: Select the latest ranging result from the historical ranging results related to the target AP as the current ranging result; Alternatively, the current ranging result can be calculated by statistically estimating multiple historical ranging results related to the target AP.

7. The ranging method as described in claim 1, wherein the step of performing a ranging operation with the target AP includes: Based on the current ranging mode of the wireless communication device, select the ranging configuration to perform the ranging operation; When the ranging mode is the energy-saving ranging mode, the ranging operation is performed using a ranging data packet with a reduced number of bursts each time. When the ranging mode is the precision-optimized ranging mode, the ranging operation is performed using a burst of complete ranging data packets.

8. The ranging method as claimed in claim 1, wherein the ranging operation is performed in accordance with the IEEE 802.11 ranging procedure, including at least one IEEE 802.11 Fine Timing Measurement (FTM) procedure and an IEEE 802.11az ranging procedure.

9. A ranging device, comprising: processor; The memory stores instructions that, when executed by the processor, enable the ranging device to: Receive ranging requests from the host system to determine the distance between the wireless communication device and the target access point (AP); Determine whether the ranging mode corresponding to the ranging request is the energy-saving ranging mode; In response to the ranging request and after determining that the ranging mode is the energy-saving ranging mode, it is determined whether the displacement of the wireless communication device exceeds a preset displacement threshold. If it is determined that the displacement does not exceed the preset displacement threshold, then based on the historical ranging results related to the target AP, a ranging result indicating the distance is generated, and ranging data packets are avoided from being sent to the target AP. If the displacement is determined to exceed the preset displacement threshold, a ranging operation is performed with the target AP to generate the ranging result.

10. The ranging device as claimed in claim 9, wherein when the instruction is executed by the processor, the ranging device is capable of: Determine whether the Received Signal Strength Indicator (RSSI) change associated with the target AP is within a preset tolerance range; If the RSSI change is within the preset tolerance range, it is determined that the displacement of the wireless communication device has not exceeded the preset displacement threshold.

11. The ranging device as claimed in claim 10, wherein when the instruction is executed by the processor, the ranging device is capable of: Determine the time difference between the current time and the timestamp associated with the previous RSSI value used to determine this RSSI change; If the time difference exceeds the stale threshold, the RSSI change is deemed unreliable, and the ranging operation is performed with the target AP to generate the ranging result.

12. The ranging device of claim 10, further comprising: RSSI processing engine, configured as follows: By passively receiving one or more beacon frames, at least one RSSI value associated with the target AP is obtained without initiating active scanning or sending a probe request, wherein the one or more beacon frames include beacon frames sent by the serving AP associated with the wireless communication device and / or beacon frames sent in the OBSS by one or more neighboring non-serving APs. Extract the at least one RSSI value from the passively received one or more beacon frames; The ranging device determines the RSSI change based on the at least one RSSI value obtained by the RSSI processing engine.

13. The ranging device as claimed in claim 9, wherein when the instruction is executed by the processor, the ranging device is capable of: Motion data is acquired from one or more inertial sensors of the wireless communication device; The displacement of the wireless communication device is estimated based on this motion data; Based on the estimated displacement and / or the motion state indicated by the motion data, it is determined whether the displacement of the wireless communication device exceeds the preset displacement.

14. The ranging device as claimed in claim 9, wherein when the instruction is executed by the processor, the ranging device: Select the latest ranging result from the historical ranging results related to the target AP as the current ranging result; or The current ranging result is calculated by statistically estimating the multiple historical ranging results related to the target AP.

15. The ranging device as claimed in claim 9, wherein when the instruction is executed by the processor, the ranging device: Select the ranging configuration for performing the ranging operation based on the operating mode of the ranging device; When the ranging mode is the power-saving ranging mode, the ranging operation is performed using a reduced number of distance measurement data packets in each burst. When the ranging mode is the precision-optimized ranging mode, the ranging operation is performed using a full number of distance measurement data packets in each burst.

16. The ranging device of claim 9, wherein the ranging operation is performed in accordance with the IEEE 802.11 ranging procedure, including at least one IEEE 802.11 Fine Timing Measurement (FTM) procedure and an IEEE 802.11az ranging procedure.

17. A wireless communication device, comprising the ranging device as described in claim 9.

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