Angle of arrival-based position determination using periodic advertisement synchronization

Abstract

Systems, apparatus, processes, and computer-readable media for wireless communication are disclosed. For example, a process may include receiving synchronization information associated with a first set of periodic advertisements (PAs) from a network entity. A first time offset from a reference time associated with synchronization of a plurality of wireless communication devices including the wireless communication device may be determined based on the synchronization information. The second set of PAs may be transmitted at a synchronization time based on the reference time and the first time offset, each PA in the second set of PAs including a constant tone extension (CTE).

Description

Technical Field

[0001] The present disclosure relates generally to wireless communications. For example, aspects of the present disclosure relate to angle-of-arrival (AoA)-based position determination in a synchronized system including one or more network devices (e.g., access points (APs)) and one or more wireless communication devices (e.g., peripheral devices such as electronic shelf labels (ESLs)). Background Art

[0002] Short-range wireless communications enable wireless communication over relatively short distances (e.g., within 30 meters). For example, Bluetooth® is a wireless technology standard for exchanging data over short distances using short-wavelength ultra-high frequency (UHF) radio waves ranging from 2.4 gigahertz (GHz) to 2.485 GHz.

[0003] Bluetooth Low Energy (BLE) is a form of Bluetooth communication that allows for communication with devices that operate at lower power. Such devices can include beacons, which are wireless communication devices that can use low-power communication technology for positioning, proximity marketing, or other purposes. In some cases, such devices can act as nodes (e.g., relay nodes) in a wireless mesh network, communicating and / or relaying information to a management platform or hub associated with the wireless mesh network. Summary of the Invention

[0004] The following presents a brief summary of one or more aspects disclosed herein. Therefore, the following summary should not be considered an extensive overview of all contemplated aspects, nor should it be considered to identify key or important elements related to all contemplated aspects or to delineate the scope of any particular aspect. Therefore, the sole purpose of the following summary is to present certain concepts related to one or more aspects of the mechanisms disclosed herein in a simplified form prior to the detailed description presented below.

[0005] Disclosed are systems, methods, apparatus, and computer-readable media for performing wireless communications. According to at least one illustrative example, a method of wireless communications performed at a wireless communication device is provided, the method comprising: receiving synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; determining a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of a plurality of wireless communication devices including the wireless communication device; and transmitting a second set of PAs at a synchronization time based on the reference time and the first time offset, each PA in the second set of PAs including a constant tone extension (CTE).

[0006] In another example, a wireless communication method performed at a wireless communication device is provided, the method comprising: receiving synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; determining a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of a plurality of wireless communication devices including the wireless communication device; and receiving a second set of PAs from a second wireless communication device among the plurality of wireless communication devices at a synchronization time based on the first time offset and the reference time, each PA in the second set of PAs comprising a constant tone extension (CTE).

[0007] In another example, a wireless communication device for wireless communication is provided. The wireless communication device includes at least one memory and at least one processor coupled to the at least one memory, the processor configured to: receive synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; determine a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of a plurality of wireless communication devices including the wireless communication device; and transmit a second set of PAs at a synchronization time based on the reference time and the first time offset, each PA in the second set of PAs including a constant tone extension (CTE).

[0008] In another example, a wireless communication device for wireless communication is provided. The wireless communication device includes at least one memory and at least one processor coupled to the at least one memory, the processor being configured to: receive synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; determine a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of a plurality of wireless communication devices including the wireless communication device; and receive a second set of PAs from a second wireless communication device in the plurality of wireless communication devices at a synchronization time based on the first time offset and the reference time, each PA in the second set of PAs including a constant tone extension (CTE).

[0009] In another example, a non-transitory computer-readable medium comprising instructions is provided that, when executed by at least one processor, causes the at least one processor to: receive synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; determine a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of a plurality of wireless communication devices including the wireless communication device; and send a second set of PAs at a synchronization time based on the reference time and the first time offset, each PA in the second set of PAs comprising a constant tone extension (CTE).

[0010] In another example, a non-transitory computer-readable medium comprising instructions is provided that, when executed by at least one processor, causes the at least one processor to: receive synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; determine a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of a plurality of wireless communication devices including the wireless communication device; and receive a second set of PAs from a second wireless communication device of the plurality of wireless communication devices at a synchronization time based on the first time offset and the reference time, each PA in the second set of PAs comprising a constant tone extension (CTE).

[0011] In another example, an apparatus for wireless communication at a wireless communication device is provided. The apparatus includes: means for receiving synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; means for determining a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of a plurality of wireless communication devices including the wireless communication device; and means for transmitting a second set of PAs at a synchronization time based on the reference time and the first time offset, each PA in the second set of PAs including a constant tone extension (CTE).

[0012] In another example, an apparatus for wireless communication at a wireless communication device is provided. The apparatus includes: means for receiving synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; means for determining a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of a plurality of wireless communication devices including the wireless communication device; and means for receiving a second set of PAs from a second wireless communication device in the plurality of wireless communication devices at a synchronization time based on the first time offset and the reference time, each PA in the second set of PAs including a constant tone extension (CTE).

[0013] Aspects generally include methods, apparatuses, systems, computer program products, non-transitory computer-readable media, user devices, user equipment, wireless communication devices, and / or processing systems substantially as described with reference to and illustrated by the figures and description.

[0014] Some aspects include a device having a processor configured to perform one or more operations of any of the methods outlined above. Further aspects include a processing device for use in a device configured with processor-executable instructions to perform the operations of any of the methods outlined above. Further aspects include a non-transitory processor-readable storage medium having stored thereon processor-executable instructions configured to cause the processor of the device to perform the operations of any of the methods outlined above. Further aspects include a device having means for performing the functions of any of the methods outlined above.

[0015] The features and technical advantages of examples of the present invention have been outlined rather broadly above in order that the detailed description that follows may be better understood. Additional features and advantages will be described below. The concepts and specific examples disclosed may be readily used as a basis for modifying or designing other structures for carrying out the same purposes of the present disclosure. Such equivalent constructions do not depart from the scope of the appended claims. The features of the concepts disclosed herein, their organization and method of operation, and related advantages will be better understood from the following description when considered in conjunction with the accompanying drawings. Each of the accompanying drawings is provided for the purpose of illustration and description and not as a definition of limitations on the claims. The foregoing and other features and aspects will become more apparent with reference to the specification, claims, and drawings.

[0016] This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used alone to determine the scope of the claimed subject matter. The subject matter should be understood by reference to the entire specification of this patent, any or all drawings, and the appropriate portion of each claim. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The accompanying drawings are used to help describe various aspects of the present invention and are only used to illustrate these aspects, not to limit them. In order to be able to understand the above-mentioned features of the present disclosure in detail, a more specific description of the above brief overview can be made with reference to some aspects, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings only illustrate certain typical aspects of the present disclosure and should not be considered as limiting its scope, as the description may admit other equally effective aspects. The same reference numerals in different drawings may identify the same or similar elements.

[0018] Figure 1 is a diagram illustrating an example environment in which the systems and / or methods described herein may be implemented, according to some examples;

[0019] Figure 2 is a diagram illustrating example components of a device according to some examples;

[0020] Figure 3 is a signaling diagram illustrating example communication transmissions according to some examples;

[0021] Figure 4 is a signaling diagram illustrating an example of communication transmissions between a network device and two groups of wireless communication devices according to some examples;

[0022] Figure 5 is a signaling diagram illustrating an example of a periodic advertisement (PA) constant tone extension (CTE) transmission using a periodic advertisement with response (PAwR) subframe according to some examples;

[0023] Figure 6 is a signaling diagram illustrating an example of steady-state PA CTE transmission between a time synchronization network device and a plurality of wireless communication devices according to some examples;

[0024] Figure 7 is a signaling diagram illustrating an example of PA CTE transmission to establish time synchronization between a network device and a plurality of wireless communication devices according to some examples;

[0025] Figure 8 is a diagram illustrating an example of connectionless synchronization that may be performed to establish time-synchronized PACTE transmissions between one or more central devices and one or more peripheral devices according to some examples;

[0026] Figure 9 is a signaling diagram illustrating an example of time-synchronized PA CTE transmissions sent by multiple wireless communication devices on a combined periodic advertising sequence (train) according to some examples;

[0027] Figure 10 is a signaling diagram illustrating an example of establishing time-synchronized PA CTE transmissions on a combined periodic advertising sequence by multiple wireless communication devices according to some examples;

[0028] Figure 11 is a flow chart illustrating an example of a wireless communication process at a wireless communication device according to some examples;

[0029] Figure 12 is a flow chart illustrating an example of a wireless communication process at a network device according to some examples; and

[0030] Figure 13 is a block diagram illustrating an example computing system that may be employed by the disclosed systems and techniques, according to some examples. DETAILED DESCRIPTION

[0031] For illustrative purposes, certain aspects of the present disclosure are provided below. Without departing from the scope of the present disclosure, alternative aspects can be designed. In addition, well-known elements of the present disclosure will not be described in detail or will be omitted to avoid confusing the relevant details of the present disclosure. It is clear to those skilled in the art that some aspects described herein can be applied independently, and some of them can be applied in combination. In the following description, for the purpose of explanation, specific details are set forth to provide a comprehensive understanding of aspects of the application. However, it is clear that each aspect can be practiced without these specific details. The drawings and description are not restrictive.

[0032] The following description provides exemplary aspects and is not intended to limit the scope, applicability, or configuration of the present invention. Instead, the following description of the exemplary aspects will provide those skilled in the art with a description of implementing the exemplary aspects. It should be understood that various changes may be made to the function and arrangement of the elements without departing from the scope of application set forth in the appended claims.

[0033] A system may include one or more wireless communication devices controlled by a network entity. For example, a system including multiple peripheral devices (e.g., an electronic shelf label (ESL) system) may include one or more wireless communication devices (e.g., peripheral devices such as ESLs) controlled by a network entity (e.g., a management entity (ME)) via at least one network device (e.g., an access point (AP)). In one or more examples, to facilitate control by the ME, each peripheral device (e.g., an ESL) may have a wireless connection (e.g., a Bluetooth Low Energy (BLE) connection or other connection) to an AP, which is communicatively connected to the ME (e.g., via the Internet, such as wirelessly, via an Ethernet connection, etc.). In some cases, commands from the ME may be wirelessly transmitted by the AP to the peripheral device (e.g., ESL). Responses or information from the peripheral device may also be received by the AP and provided by the AP to the ME. Each AP may have an associated channel map. A channel map is a list of frequency channels that are used or not used (e.g., in the case of a modified frequency hopping sequence) by the AP for communications, such as with the ESL or other peripheral devices. Although examples are described herein using an ESL as an illustrative example of a wireless communication device, a management entity as an example of a network entity, and an access point as an example of a network device, the systems and techniques described herein are applicable to any type of system or network.

[0034] In some examples, an ESL system can be deployed to support and manage ESL equipment in stores (e.g., supermarkets) and other retail spaces. In some examples, the ESL system can be deployed to support and manage ESL equipment in warehouses (e.g., distribution centers) and other industrial spaces. For example, in a store, an ESL can be provided as an electronic label that is affixed to store shelves to identify the items on the shelf above the label and the item's price. Each ESL can be implemented with a display (e.g., a liquid crystal display (LCD), an electronic paper (e-paper) display, etc.). The ESL can digitally display the item's name, its product identification number, such as its stock keeping unit (SKU) number, and its price. The ESL can also display the item's barcode, its Quick Response (QR) code, and / or an image (e.g., a picture) of the item. In some examples, each ESL can include a display and a radio or wireless transceiver for communicating with one or more APs and / or MEs included in the ESL system. For example, during operation of the ESL system, the information displayed on the ESL can be periodically updated using periodic advertisements (PAs), as described in more detail below.

[0035] As previously described, in some examples, the ESL system can be used additionally or alternatively to support and manage ESL equipment in warehouses (e.g., distribution) and other industrial spaces. For example, in a warehouse or distribution center, the ESL equipment can be provided as a tracker that is attached to pallets or various other shipping containers that are moved throughout the warehouse and / or transported in the supply chain. In some examples, the tracker can be provided as a printed active (e.g., battery-powered) Bluetooth Low Energy (BLE) tag. The BLE tracker can be implemented based on the ESL protocol (e.g., can comply with the ESL protocol). For example, the BLE tracker can be attached to a pallet of goods and used to track the pallet of goods as it moves from a global distribution center (GDC) to a retail store environment.

[0036] In an ESL system, periodic advertisements (PAs) can be used to provide regular and predictable payload transmissions from a network device (e.g., such as an AP) to one or more wireless communication devices (e.g., such as an ESL). For example, PAs can be used to distribute information from a network device to multiple wireless communication devices, which may be within one or more wireless communication device groups. PAs are typically unidirectional (e.g., one-way transmissions), such that PAs are only transmitted in one direction from a network device (e.g., an AP) to one or more wireless communication devices (e.g., an ESL). In some examples, information displayed on an ESL can be periodically updated using periodic advertisements (PAs), as described above.

[0037] Periodic Advertisement with Response (PAwR) can be used in ESL systems to provide bidirectionality (e.g., bidirectional transmissions between a central device and one or more peripheral devices). Whenever a network device chooses to send a request to a wireless communication device (e.g., on a synchronization sub-event), synchronized wireless communication devices within a wireless communication device group (e.g., peripheral devices such as ESLs) can be addressed by the network device (e.g., an AP) on a synchronization channel (e.g., a radio frequency (RF) channel between the network device and the wireless communication device). In some cases, as used herein, a synchronization channel refers to a channel on which transmissions are synchronized (in time). For example, a channel may utilize or be based on a frequency over which one or more communications are transmitted. A frequency hopping sequence may be associated with the channel, where the frequency hopping sequence advances at fixed and / or predetermined intervals. A central device (e.g., an AP, ME, etc.) and one or more peripheral devices (e.g., an ESL) can simultaneously track the frequency hopping sequence in a predefined frequency hopping pattern (e.g., so that the central device knows when to send a request and the peripheral device knows when to listen for and / or receive a request).

[0038] In some cases, the request sent by the central device to the peripheral devices in a particular group may be a PA containing a synchronization message sent by the central device to the peripheral devices in the particular group on a synchronization channel. For example, an AUX_SYNC_SUBEVENT_IND message may contain an AP Sync command. For example, wireless communication devices (e.g., ESLs) within a particular group may wake up (e.g., from low-power (LP) mode) on the same PA transmission relative to a specific PAwR sequence for the group. For example, ESLs within a particular group may wake up at the same specific subframe within a plurality of subframes (e.g., a PA frame may include 128 subframes with a subinterval of 12.5 ms). A PA transmission may include a collection of periodic transmissions, which, when applied to PAwR, may be collectively referred to as a PA sequence or PAwR sequence. Each transmission of a PA sequence (or PAwR sequence) occurs at a precise point in time, with a fixed interval between transmissions. A communication channel (e.g., one of 37 available communication channels) is selected for each transmission, where the communication channel follows a frequency hopping sequence.

[0039] Synchronization between the central device and peripheral devices in a group can be based on the periodicity of the PA. A periodically transmitted message (e.g., a synchronization message) can include zero, one, or more commands (e.g., corresponding operation codes (OpCodes) and parameters associated with each command). For example, a synchronization message can include an AUX_SYNC_IND message associated with a PA sequence and / or an AUX_SYNC_SUBEVENT_IND message associated with a PAwR of an AP / ESL. If a network device expects a response from a wireless communication device (e.g., a synchronization message from the network device requests a response from a specific wireless communication device), the specific wireless communication device can respond in a designated response time slot, which can be based on the position of the wireless communication device in the sequence included in the synchronization message transmitted by the network device.

[0040] In some cases, one or more ESLs can be physically moved to a new location. For example, one or more ESLs can be moved from one location in a retail store (e.g., a specific shelf or storage area) to a different location in the retail store, a different retail store location, etc. In some examples, store shelves (e.g., with multiple ESLs attached) can be attached to gondolas that allow the shelves and the products provided on the shelves to be moved or repositioned. In another example, ESLs provided as trackers (e.g., such as printed active BLE tags) can be physically moved during the transport of pallets (e.g., with the trackers attached thereto) from a distribution center to a retail store location.

[0041] In some examples, an ESL system may be associated with one or more location systems that can be used to determine location information for the ESL device and / or for specific items to which the ESL device is attached or otherwise associated. For example, location information can be determined in the ESL system based on one or more angle of arrival (AoA) measurements. An AoA measurement can indicate the relative direction from which a propagating radio frequency (RF) wave transmitted by an antenna (e.g., an antenna of a transmitting device) is incident on an antenna array (e.g., an antenna array of a receiving device).

[0042] AoA measurements can be used to determine the location information of a static (e.g., non-mobile or stationary) wireless communication device. AoA measurements can also or alternatively be used to determine the location information of a mobile wireless communication device. AoA measurements can be obtained based on an AoA transmitter device (e.g., a first wireless communication device) transmitting one or more predetermined signals using a single antenna, and an AoA receiver device (e.g., a second wireless communication device) receiving the transmitted signals using at least two antennas of a multi-antenna array. For example, the AoA transmitter device can transmit one or more direction-finding signals using a single antenna, while the AoA receiver device can receive some (or all) of the direction-finding signals using a multi-antenna array. Based on the receiver receiving the AoA signals using the multi-antenna array, one or more phase differences between the AoA signals received at different antennas of the multi-antenna array can be determined. In some examples, the direction of the transmitter (e.g., relative to the receiver, relative to the multi-antenna array, etc.) can be determined based on the calculated phase differences. For example, the angle of arrival can be determined based on the wavelength of the AoA signal, the distance between the antennas of the multi-antenna array, and the phase of the AoA signal received at each antenna of the multi-antenna array.

[0043] In some examples, AoA information may be determined using one or more constant tone extensions (CTEs). For example, one or more AoA transmitters may generate and transmit signals, each including a CTE field. One or more AoA receivers may receive the transmitted signals, each including a CTE field, and may subsequently determine a phase measurement and / or phase difference based on phase information of each received CTE using the CTE field. In some examples, the CTE field may include a bit sequence with a variable duration ranging from 16 μs to 160 μs. For example, the CTE field may contain a 1-bit modulation sequence transmitted at a single frequency and a constant wavelength. The CTE signal may be un-whitened (e.g., not subjected to whitening, a process of scrambling a signal to ensure that there are no long strings of 1s or 0s). In some cases, measuring the phase of a CTE signal (e.g., determining AoA information based on measuring the phase of a received signal) based on a CTE signal comprising an un-whitened bit sequence transmitted at the same frequency and a constant wavelength may be easier and / or more efficient than for various other signals.

[0044] In some examples, an ESL device and / or ESL system can perform AoA-based location determination based on a CTE field appended to another transmission. For example, a CTE can be appended to an existing transmission, such as a periodic advertisement (PA). A periodic advertisement including a CTE may also be referred to herein as a PA CTE. Some AoA-based location determination tasks performed by an ESL device and / or ESL system can be based on receiving multiple PA CTEs (e.g., multiple PAs, each including a CTE field) from multiple PA transmitters. For example, ESL-based AoA location determination performed for triangulation, static, and / or mobile use cases may require an ESL (e.g., configured as an AoA receiver) to measure the PA CTEs from multiple different PA transmitters.

[0045] In some cases, the accuracy of AoA measurements and determinations based on PA CTEs transmitted by multiple different PA transmitters can be based on the synchronization (or lack of synchronization) that exists between the multiple PA transmitters. For example, other PAs (e.g., PAs not enhanced with CTE) can also transmit in the same wireless environment as the PA CTEs used by the ESL AoA location determination system. For example, the PA CTEs used to perform AoA-based location determination can exist on a shared wireless medium with various other PAs used by ESL devices and the ESL system.

[0046] Time synchronization must be maintained between the ESLs participating in the AoA measurement. For example, time synchronization must be maintained between the Tx ESL transmitting packets and the Rx ESL receiving packets. Time synchronization must also be maintained between the multiple different Tx ESLs transmitting each PA CTE. If some (or all) of the Tx ESLs and Rx ESLs participating in the AoA measurement using the PA CTE are out of sync or experience drift from their previous synchronization state, collisions or conflicts may occur between the AoA PA CTE and other PAs on the wireless medium.

[0047] For example, some (or all) of the Tx ESLs and Rx ESLs may be associated with a periodic advertisement (PAwR) sequence with responses that is transmitted and received on a predetermined time slot. In the case of synchronization between the ESLs, the transmit and receive time slots for the AoA PA CTE may be separated from the predetermined time slots associated with the ESL's existing PAwR sequence. Timing drift and other degradations in synchronization can cause AoA PA CTE transmissions and PAwR transmissions to collide or conflict. For example, if timing drift or loss of synchronization causes an AoA Tx ESL to attempt to transmit a PA CTE on the same time slot as an existing PAwR transmission, the AoA Tx ESL may be unable to transmit the scheduled PA CTE. Similarly, if timing drift or loss of synchronization causes an AoA Rx ESL to attempt to receive a PA CTE on the same time slot as an existing PAwR reception, the AoA Rx ESL may be unable to receive the scheduled PA CTE.

[0048] There is a need for systems and techniques that can be used to establish and maintain time synchronization between ESLs associated with transmitting or receiving AoA PA CTEs. For example, there is a need for systems and techniques that can be used to prevent PA CTE drift relative to a PAwR sequence and / or that can be used to synchronize multiple AoA PA CTEs (e.g., so that an AoA Rx ESL can receive multiple mutually synchronized AoA PACTEs transmitted by different ESLs). There is also a need for providing mutually synchronized AoA PA CTEs across multiple PAwR sequences (e.g., across multiple APs, each associated with a different PAwR sequence). There is also a need for systems and techniques that can maintain time synchronization and avoid collisions when providing AoA PA CTE transmissions on multiple different PA CTE sequences. For example, there is a need for systems and techniques that can maintain time synchronization between AoA Tx and Rx ESLs utilizing multiple PA CTE sequences such that PACTE transmissions for a given PA CTE sequence do not collide or conflict with PACTE transmissions for any other PA CTE sequence, and further do not collide or conflict with PAwR transmissions for any PAwR sequence associated with the AoA Tx and Rx ESLs.

[0049] This document describes systems and techniques that can be used to perform location determination based on periodic advertisement (PA) synchronization. For example, these systems and techniques can be used to perform angle of arrival (AoA)-based location determination based on PA synchronization. In some examples, AoA-based location determination can be performed using one or more wireless communication devices (e.g., such as electronic shelf labels (ESLs) or other peripheral devices). In some cases, PA synchronization can be performed using an access point (AP) synchronization system. The AP synchronization system can be included in or provided as an ESL system.

[0050] In some examples, AoA information and / or AoA-based location information can be determined based on one or more constant tone extensions (CTEs). For example, one or more wireless communication devices (e.g., ESLs) can transmit one or more periodic advertisements with constant tone extensions (PA CTEs). The one or more PA CTEs can be included in a periodic advertisement sequence (e.g., a PA sequence) or otherwise associated with the periodic advertisement sequence. The PA sequence of a PA CTE can also be referred to as a PA CTE sequence. A wireless communication device (e.g., an ESL) that transmits or forms a PA CTE sequence for AoA-based location determination can also be referred to herein as a Tx ESL or an AoA Tx ESL. One or more wireless communication devices (e.g., an ESL) can receive the one or more PA CTEs transmitted by the Tx ESL. A wireless communication device (e.g., an ESL) that receives the PA CTEs transmitted by the Tx ESL can also be referred to herein as a Rx ESL or an AoA Rx ESL.

[0051] In some examples, a shared or common start time (e.g., a synchronized start time) can be determined for one or more PA sequences associated with the Tx and Rx ESLs. For example, each AoA Tx ESL can form a corresponding PA sequence for transmitting a PA CTE. In one illustrative example, each AoA Tx ESL can form its corresponding PA sequence at a start time based on the synchronized start time (e.g., shared among all AoA Tx ESLs) and a separate offset for collision avoidance (e.g., specific to each respective AoA Tx ESL in the AoA Tx ESLs). Each Rx ESL can synchronize with some (or all) of the PA sequences formed by the Tx ESLs and can receive multiple PA CTEs transmitted by the Tx ESLs. In some examples, by forming the Tx ESL PA sequence and the Rx ESL PA sequence using the same start time, the systems and techniques can synchronize the Tx ESLs and the Rx ESLs (e.g., the systems and techniques can synchronize AoA-based position determination performed using the Tx and Rx ESLs).

[0052] In some cases, the synchronization start time can be determined based on a common synchronization clock associated with the Tx and Rx ESLs. For example, the synchronization start time can be determined based on the synchronization clock of an access point (AP) or other network entity associated with the Tx and Rx ESLs. In some examples, the synchronization start time can be determined based on one or more AP synchronization messages (e.g., AP_SYNC packets). For example, the AP_SYNC packets can be used to perform time synchronization between an AP and one or more ESLs associated with the AP (e.g., one or more Tx ESLs and one or more Rx ESLs). In some aspects, the synchronization start time for the Tx and Rx ESL PA CTE sequence used to perform AoA-based position determination can be provided as an offset relative to an existing periodic advertisement (PA). In some aspects, using a separate synchronization start time and offset for each AoA Tx ESL can be used to avoid conflicts between different PA CTE sequences (e.g., formed by different AoA Tx ESLs) and can also be used to avoid conflicts with existing PAwR sequences (e.g., between an AP and ESLs, including Tx and Rx ESLs). In some examples, the AoA Tx ESL can form a corresponding PA CTE sequence to avoid collision with the frequently used response time slots of the AP_SYNC message and / or PAwR sequence.

[0053] For example, the PACTE sequences of the Tx and Rx ESLs can each be associated with the same synchronization start time, where the synchronization start time is determined as an offset from a periodic advertisement with response (PAwR) sub-event. A PAwR sub-event (e.g., of a PAwR sequence) and a PACTE sequence can be associated with the same Tx and Rx ESLs. For example, the Tx and Rx ESLs can be associated with or identified by a group identifier (e.g., a group ID). The PAwR sub-events and / or PAwR sequences, as well as the PACTE sequence, can each be associated with the same group ID for the Tx and Rx ESLs.

[0054] In some examples, systems and techniques can use synchronization information (e.g., syncInfo) of common existing PA sequences to determine syncInfo for one or more PA CTE sequences. For example, synchronization information for forming one or more PA CTE sequences using Tx and Rx ESLs can be generated based on synchronization information of an existing PAwR sequence associated with a group including Tx and Rx ESLs.

[0055] In one illustrative example, the Tx and Rx ESLs may be included in a group associated with an AP (e.g., the Tx and Rx ESLs are connected to and in communication with the same AP). In such an example, synchronization information used to form a PA CTE sequence that can be used to perform AoA-based position determination can be determined based on synchronization information of a PAwR sequence associated with the AP. For example, the PAwR sequence can include one or more synchronization messages (e.g., such as AP_SYNC packets) sent by the AP to the Tx and Rx ESLs. In some aspects, the synchronization information used to form the PA CTE sequence can include at least a portion of the PAwR sequence synchronization information as well as new or additional synchronization information, which can be used to identify a corresponding one of the PA CTE sequences to be formed.

[0056] Additional aspects of the invention are described with reference to the accompanying drawings.

[0057] Figure 1 is a diagram of an example environment 100 in which the systems and / or methods described herein may be implemented. Figure 1 As shown, environment 100 may include at least one access point (AP) 110, at least one wireless communication device 120, a management entity (ME) 130, and a network 140. The devices of environment 100 may be interconnected via wired connections, wireless connections, or a combination of wired and wireless connections.

[0058] The access point 110 may include one or more devices capable of receiving, generating, storing, processing, providing, and / or routing information associated with access point synchronization and / or handover, as described elsewhere herein. The access point 110 may include a communication device and / or a computing device. The access point 110 may be configured to transmit beacons (e.g., BLE beacons) and to scan for and locate other devices (e.g., other devices communicating using the BLE protocol).

[0059] The wireless communication device 120 may include one or more devices capable of receiving, generating, storing, processing, and / or providing information associated with access point synchronization and / or handover, as described elsewhere herein. The wireless communication device 120 may include a communication device and / or a computing device. In some aspects, the wireless communication device 120 may be, may include, or may be included in an electronic shelf label (ESL).

[0060] Management entity 130 includes one or more devices capable of receiving, generating, storing, processing, providing, and / or routing information associated with access point synchronization and / or handover, as described elsewhere herein. Management entity 130 may include a communication device and / or a computing device. For example, management entity 130 may include a server, such as an application server, a client server, a web server, a database server, a host server, a proxy server, a virtual server (e.g., executed on computing hardware), or a server in a cloud computing system. In some aspects, management entity 130 includes computing hardware used in a cloud computing environment. Management entity 130 may provide control for a system (e.g., an ESL system) including access point 110, wireless communication device 120, and / or device 130. Access point 110 may be communicatively coupled to management entity 130 via a network (not shown), such as the Internet.

[0061] Network 140 may include one or more wireless networks. For example, network 140 may include a personal area network (eg, a Bluetooth network). Network 140 enables communication between devices in environment 100.

[0062] Figure 1 The number and arrangement of devices and networks shown are provided as examples. Figure 1 There may be additional devices and / or networks, fewer devices and / or networks, different devices and / or networks, or a different arrangement of devices and / or networks than those shown in FIG. Figure 1 Two or more of the devices shown may be implemented in a single device, or Figure 1 The single device shown may be implemented as multiple distributed devices. Additionally or alternatively, a collection of devices (eg, one or more devices) of environment 100 may perform one or more functions described as being performed by another collection of devices of environment 100.

[0063] Figure 2 is a diagram illustrating example components of a device 200 according to the present disclosure. The device 200 may correspond to the access point 110, the wireless communication device 120, and / or the management entity 130. In some aspects, the access point 110, the wireless communication device 120, and / or the management entity 130 may include one or more devices 200 and / or one or more components of the device 200. Figure 2 As shown, device 200 may include a bus 205 , a processor 210 , a memory 215 , a storage component 220 , an input component 225 , an output component 230 , and / or a communication component 235 .

[0064] The bus 205 may include components that allow communication between components of the device 200. The processor 210 may be implemented in hardware, firmware, or a combination of hardware and software. The processor 210 may be a central processing unit (CPU), a graphics processing unit (GPU), an accelerated processing unit (APU), a microprocessor, a microcontroller, a digital signal processor (DSP), a field programmable gate array (FPGA), an application-specific integrated circuit (ASIC), or other types of processing components. In some aspects, the processor 210 may include one or more processors that can be programmed to perform functions. The memory 215 may include random access memory (RAM), read-only memory (ROM), and / or another type of dynamic or static storage device (e.g., flash memory, magnetic memory, and / or optical memory) that stores information and / or instructions for use by the processor 210.

[0065] The storage component 220 may store information and / or software related to the operation and use of the device 200. For example, the storage component 220 may include a hard disk (e.g., a magnetic disk, an optical disk, a magneto-optical disk, and / or a solid-state disk), a compact disk (CD), a digital versatile disk (DVD), a floppy disk, a cassette, a magnetic tape, and / or another type of non-transitory computer-readable medium, and a corresponding drive.

[0066] Input components 225 may include components that allow device 200 to receive information, such as via user input (e.g., a touch screen display, a keyboard, a keypad, a mouse, buttons, switches, and / or a microphone). Additionally or alternatively, input components 225 may include components for determining the location or position of device 200 (e.g., a global positioning system (GPS) component or a global navigation satellite system (GNSS) component) and / or sensors for sensing information (e.g., an accelerometer, a gyroscope, an actuator, or another type of positioning or environmental sensor). Output components 230 may include components that provide output information from device 200 (e.g., a display, a speaker, a tactile feedback component, and / or an audio or visual indicator).

[0067] The communication component 235 may include one or more transceiver-like components (e.g., a transceiver and / or a separate receiver and transmitter) so that the device 200 can communicate with other devices, such as via a wired connection, a wireless connection, or a combination of wired and wireless connections. The communication component 235 may allow the device 200 to receive information from another device and / or provide information to another device. For example, the communication component 235 may include an Ethernet interface, an optical interface, a coaxial interface, an infrared interface, a radio frequency interface, a universal serial bus (USB) interface, a wireless local area network interface (e.g., a Wi-Fi interface or a BLE interface), and / or a cellular network interface.

[0068] Communication component 235 may include one or more antennas for receiving wireless radio frequency (RF) signals transmitted from one or more other devices, cloud networks, and the like. The antenna may be a single antenna or an antenna array (e.g., a phased array antenna) that facilitates simultaneous transmit and receive functionality. The antenna may be an omnidirectional antenna, capable of receiving signals from all directions and transmitting signals in all directions. The wireless signals may be transmitted via a wireless network fs. The wireless network may be any wireless network, such as a cellular or telecommunications network (e.g., 3G, 4G, 5G, etc.), a wireless local area network (e.g., a WiFi network), a Bluetooth network, and / or other networks.

[0069] One or more transceiver-like components (e.g., a wireless transceiver) of the communication component 235 may include a radio frequency front end, which includes one or more components such as amplifiers, mixers for downconverting signals (also known as signal multipliers), frequency synthesizers (also known as oscillators) that provide signals to the mixers, baseband filters, analog-to-digital converters (ADCs), one or more power amplifiers, and other components. The RF front end generally handles the selection and conversion of wireless signals to baseband or intermediate frequencies and may convert RF signals to the digital domain.

[0070] In some cases, a CODEC can be implemented (e.g., by processor 210) to encode and / or decode data transmitted and / or received using one or more wireless transceivers. In some cases, encryption-decryption can be implemented (e.g., by processor 210) to encrypt and / or decrypt data transmitted and / or received by one or more wireless transceivers (e.g., according to the Advanced Encryption Standard (AES) and / or the Data Encryption Standard (DES)).

[0071] In some aspects, device 200 may represent an ESL. In addition to the components described above, the ESL may include a battery. In some aspects, the output component 230 of the ESL may be an electronic paper (e-paper) display or a liquid crystal display (LCD).

[0072] Device 200 can perform one or more of the processes described herein. Device 200 can perform these processes based on processor 210 executing software instructions stored by a non-transitory computer-readable medium such as memory 215 and / or storage component 220. Computer-readable media is defined herein as a non-transitory memory device. A memory device includes memory space within a single physical storage device or memory space distributed across multiple physical storage devices.

[0073] The software instructions may be read into the memory 215 and / or storage component 220 from another computer-readable medium or from another device via the communication component 235. When executed, the software instructions stored in the memory 215 and / or storage component 220 may cause the processor 210 to perform one or more processes described herein. Additionally or alternatively, hardwired circuitry may be used in place of or in combination with the software instructions to perform one or more processes described herein. Thus, the aspects described herein are not limited to any specific combination of hardware circuitry and software.

[0074] Figure 2 The number and arrangement of components shown are provided as examples. In practice, the device 200 may include more than Figure 2 More components, fewer components, different components, or components in a different arrangement may be shown in FIG. Additionally or alternatively, a collection of components of device 200 (eg, one or more components) may perform one or more functions described as being performed by another collection of components of device 200.

[0075] Figure 3 and Figure 4 A signaling diagram illustrating an example of PAwR in an ESL system is shown. For example, Figure 3 The signaling diagram of FIG. 1 shows an example PAwR of a group of wireless network devices (eg, device 1 305a, device 2 305b, device 3 305c, device 4 305d, and device 5 305e), and Figure 4 The signaling diagram of FIG shows an example PAwR of two groups of wireless network devices 420a, 420b (eg, the first group includes ESL1 to ESL11, and the second group includes ESL12 to ESL22). Specifically, Figure 3 is a signal timing diagram illustrating a portion of the communication between an access point (eg, access point 110) and a wireless communication device 120 (eg, ESL). Figure 1 , Figure 3 The signal sequence shown can be represented by Figure 1 This is accomplished by one or more communication connections, access points 110 and / or wireless communication devices 120.

[0076] Figure 3 Devices (e.g., device 1 305a, device 2 305b, device 3 305c, device 4 305d, and device 5 305e) can access the Figure 1305d and 305e) can each receive a periodic advertisement (PA) during a scanning cycle 310. The scanning cycle 310 can occur at regularly scheduled intervals and can be repeated periodically so that devices (e.g., device 1 305a, device 2 305b, device 3 305c, device 4 305d, and device 5 305e) can wake up to scan for messages during the repeated scanning cycle 310. Figure 1 The access point 110 of FIG. 110 may provide periodic advertisements (PAs) to devices (eg, device 1 305a, device 2 305b, device 3 305c, device 4 305d, and device 5 305e) via broadcast or multicast during a scanning period 310. Figure 1 For access point 110, scanning period 310 may be its main transmission period. In some cases, scanning period 310 may not be a fixed time because the access point (e.g., Figure 1 The access point 110 may send data of varying lengths from the beginning of the scanning period 310 .

[0077] The transmission may include multiple advertisements in a sequence. One or more portions of the advertisement may be directed to one or more devices (e.g., device 1 305a, device 2 305b, device 3 305c, device 4 305d, and device 5 305e). The devices (e.g., device 1 305a, device 2 305b, device 3 305c, device 4 305d, and device 5 305e) may decode or filter the message sent to each designated device during the reception period by all devices. In this manner, the devices (e.g., device 1 305a, device 2 305b, device 3 305c, device 4 305d, and device 5 305e) may be reprogrammed, updated, and / or received from an access point (e.g., Figure 1 110) or through an access point (e.g., Figure 1 access point 110) from another device (e.g., Figure 1 Management entity 130). From the access point (e.g., Figure 1 A periodic advertisement (PA) from the access point 110 may set a response period for one or more devices (eg, device 1 305a, device 2 305b, device 3 305c, device 4 305d, and device 5 305e).

[0078] As shown, devices (e.g., device 1 305a, device 2 305b, device 3 305c, device 4 305d, and device 5 305e) are each assigned a response period 320, 322, 324, 326, 328 within a time period following a scan period 310. In some cases, the response time assignment for a particular device may not be permanent. In some aspects, the assignment may be inferred from the payload of the synchronization message. The first response period 320 may begin after an idle time 315 following the scan period 310, where the idle period is long enough to provide the transmitter device with an opportunity to engage in other Bluetooth-related activities. The assigned response periods may also be limited to or specify a specific frequency of the channel to respond to. For example, in Figure 3 , device 1 305a is assigned a response period 320, device 2 305b is assigned a response period 322, device 3 305c is assigned a response period 324, device 4 305d is assigned a response period 326, and device 5 305e is assigned a response period 328. Figure 1 The access point 110 may store properties of devices (e.g., device 1 305a, device 2 305b, device 3 305c, device 4 305d, and device 5 305e), including whether the devices are capable of transmitting or responding. PA signaling followed by responses may be referred to as periodic advertisement with multiple responses (PAwMR).

[0079] For example, device 3 305c (e.g., Figure 1 The wireless communication device 120 may be an ESL and may scan for a signal from an access point (e.g., Figure 1 The PA received at device 3 305c may include a specified start time for the response period 324 or may include a schedule of response start times for devices including device 3 305c. Device 3 305c may provide a response to an access point (e.g., Figure 1 The response of device 3 305c may include an acknowledgement, a status code, and / or other information such as battery life, received signal strength, and / or an error notification. The response of device 3 305c may include an acknowledgement, a status code, and / or other information such as battery life, received signal strength, and / or an error notification. Figure 1 The response may include a packet with a header and may conform to any Bluetooth protocol. The response may be sent to an access point (e.g., an access point 110) in a data channel of the Bluetooth protocol. Figure 1 The PA and responses from all devices (eg, device 1 305a, device 2 305b, device 3 305c, device 4 305d, and device 5 305e) may use a channel of the Bluetooth protocol.

[0080] A device that has been allocated a response period (e.g., device 5 305e) may not respond and may determine that it has no signal to send. For example, a device (e.g., device 1 305a, device 2 305b, device 3 305c, device 4 305d, and device 5 305e) may determine what response (if any) is required and may or may not respond to a signal from an access point (e.g., Figure 1 Response periods 320, 322, 324, 326, 328 may be allocated based on a request for such periods in open transmission time sent to an access point (e.g., Figure 1 The response cycles 320, 322, 324, 326, 328 may be based on the access point (e.g., Figure 1 The PA messages and responses may be frequency hopping, time synchronized channels, and / or extensions of the Bluetooth advertising channel.

[0081] As mentioned earlier, Figure 4 An example PAwR is shown for two groups of wireless network devices 420a, 420b (eg, a first group includes ESL 1 through ESL 11, and a second group includes ESL 12 through ESL 22). Specifically, Figure 4 is a signaling diagram illustrating an example of communication transmission 400 between a network device 410 (eg, a central device, which may be an access point) and two groups of wireless communication devices 420a, 420b (eg, peripheral devices, which may be ESLs). Figure 1 , Figure 4 The signal sequence shown can be represented by Figure 1 This is accomplished by one or more communication connections, access points 110 and / or wireless communication devices 120.

[0082] exist Figure 4 In FIG, a signaling diagram is shown in a graph, with the x-axis representing time in milliseconds (ms) and the y-axis representing a designated wireless communication device 420 a, 420 b (e.g., ESL1, ESL2, ESL3, ESL4, ESL5, ESL6, ESL7, ESL8, ESL9, ESL10, ESL11, ESL12, ESL13, ESL14, ESL15, ESL16, ESL17, ESL18, ESL19, ESL20, ESL21, and ESL22). Specifically, Figure 4The x-axis of the graph represents time starting at 0 ms and ending at 25 ms. This time can be split into two subframes, each of which is 12.5 ms long. Thus, the two subframes can include a first subframe from 0 ms to 12.5 ms, and a second subframe from 12.5 ms to 25 ms. In one or more examples, there can be more or less than the following subframes: Figure 4 The two subframes shown, and / or each subframe may be longer or shorter than Figure 4 12.5ms shown.

[0083] In one or more examples, wireless communication devices 420a, 420b (e.g., peripheral devices) can be assigned (e.g., by network device 410 and / or by a network entity, such as a management entity) to different groups (e.g., two groups) of wireless communication devices 420a, 420b. For example, wireless communication devices 420a (e.g., ESL1, ESL2, ESL3, ESL4, ESL5, ESL6, ESL7, ESL8, ESL9, ESL10, and ESL11) can be assigned to a first group (e.g., Group 1), and wireless communication devices 420b (e.g., ESL12, ESL13, ESL14, ESL15, ESL16, ESL17, ESL18, ESL19, ESL20, ESL21, and ESL22) can be assigned to a second group (e.g., Group 2).

[0084] exist Figure 4 In the example, during PAwR operation, at time 0 ms of a first time subframe, a network device 410 (e.g., a central device such as an AP) may send 430a a PA message including a synchronization message to a first group (e.g., Group 1) of wireless communication devices 420a (e.g., ESL 1, ESL 2, ESL 3, ESL 4, ESL 5, ESL 6, ESL 7, ESL 8, ESL 9, ESL 10, and ESL 11) via a synchronization channel between the network device 410 and the wireless communication devices 420a, 420b. As previously described, the synchronization message may include one or more commands. For example, a command may include an operation code (OpCode) and parameters associated with the command. At time 0 ms, a first group of wireless communication devices 420a (e.g., ESL 1, ESL 2, ESL 3, ESL 4, ESL 5, ESL 6, ESL 7, ESL 8, ESL 9, ESL 10, and ESL 11) may receive 435a a PA containing a synchronization message over a synchronization channel.

[0085] In one or more examples, the network device 410 can be configured to transmit the PA at specified time intervals (eg, time subframes), such as Figure 4 In one or more examples, the specified time interval (e.g., subframe) can be shorter or longer than Figure 4 The wireless communication devices 420a, 420b may respond to the PA in a timely manner by using their designated respective response time slots.

[0086] In one or more examples, a synchronization message sent 430a to a first group (e.g., Group 1) of wireless communication devices 420a (e.g., ESL 1, ESL2, ESL 3, ESL 4, ESL 5, ESL 6, ESL 7, ESL 8, ESL 9, ESL 10, and ESL 11) can indicate corresponding response time slots for one or more wireless communication devices 420a in the first group (e.g., ESL 1, ESL 2, ESL 3, ESL 4, ESL5, ESL 6, ESL 7, ESL 8, ESL 9, ESL 10, and / or ESL 11) to send 440a responses to the network device 410. If wireless communication device 420a (e.g., ESL 1, ESL 2, ESL 3, ESL 4, ESL 5, ESL 6, ESL 7, ESL 8, ESL 9, ESL 10, and ESL 11) is addressed within the synchronization message, wireless communication device 420a (e.g., ESL 1, ESL 2, ESL 3, ESL 4, ESL 5, ESL 6, ESL 7, ESL 8, ESL 9, ESL 10, and ESL 11) may respond (e.g., send 440a) in its corresponding response time slot as indicated within the synchronization message.

[0087] For example, the synchronization message may instruct one or more wireless communication devices 420a (e.g., ESL 1, ESL 2, ESL3, ESL 4, ESL 5, ESL 6, ESL 7, ESL 8, ESL 9, ESL 10, and / or ESL 11) to respond (e.g., transmit 440a) in a timely manner to a specified sequence (e.g., in a response time slot located every 0.625 ms after 5 ms has passed after the start of a subframe). For example, the sequence may indicate that the wireless communication device 420a (e.g., ESL 1) should respond in a response time slot at 5 ms, the wireless communication device 420a (e.g., ESL 2) should respond in a response time slot at 5.625 ms, the wireless communication device 420a (e.g., ESL 3) should respond in a response time slot at 6.25 ms, the wireless communication device 420a (e.g., ESL 4) should respond in a response time slot at 6.875 ms, the wireless communication device 420a (e.g., ESL 5) should respond in a response time slot at 7.5 ms, the wireless communication device 420a (e.g., ESL 6) should respond in a response time slot at 8.125 ms, the wireless communication device 420a (e.g., ESL 7) should respond in a response time slot at 8.75 ms, and the wireless communication device 420a (e.g., ESL 8) should respond in a response time slot at 9.375 ms. ms, wireless communication device 420a (e.g., ESL 9) should respond in the response slot at 10 ms, wireless communication device 420a (e.g., ESL 10) should respond in the response slot at 10.625 ms, and wireless communication device 420b (e.g., ESL 11) should respond in the response slot at 11.25 ms.

[0088] After the wireless communication devices 420a (e.g., ESL 1, ESL 2, ESL 3, ESL 4, ESL 5, ESL 6, ESL 7, ESL8, ESL 9, ESL 10, and ESL 11) have received 435a the PA containing the synchronization message from the network device 410, one or more of the wireless communication devices 420a (e.g., ESL 1, ESL 2, ESL 3, ESL 4, ESL 5, ESL 6, ESL 7, ESL 8, ESL 9, ESL 10, and ESL 11) may send 440a their responses within their respective response time slots according to the sequence specified within the synchronization message. After one or more wireless communication devices 420a (e.g., ESL 1, ESL 2, ESL 3, ESL 4, ESL 5, ESL 6, ESL 7, ESL 8, ESL 9, ESL 10, and / or ESL 11) have sent 440a their responses in their respective time slots, the network device 410 may receive 445a their sent responses at those designated response time slots.

[0089] Then, during the PAwR operation, at 12.5 ms of the second subframe time, the network device 410 may transmit 430b a PA including a synchronization message to a second group (e.g., Group 2) of wireless communication devices 420b (e.g., ESL 12, ESL 13, ESL 14, ESL 15, ESL 16, ESL 17, ESL 18, ESL 19, ESL 20, ESL 21, and ESL 22) via a synchronization channel between the network device 410 and the wireless communication devices 420a and 420b. Additionally, at time 12.5 ms, the second group of wireless communication devices 420b (e.g., ESL 12, ESL 13, ESL 14, ESL 15, ESL 16, ESL 17, ESL 18, ESL 19, ESL 20, ESL 21, and ESL 22) may receive 435b a PA including a synchronization message via the synchronization channel.

[0090] The synchronization message sent 430b to a second group (e.g., Group 2) of wireless communication devices 420b (e.g., ESL 12, ESL 13, ESL 14, ESL 15, ESL 16, ESL 17, ESL 18, ESL 19, ESL 20, ESL 21, and ESL 22) may indicate corresponding response time slots for one or more wireless communication devices 420b in the second group (e.g., ESL 12, ESL 13, ESL 14, ESL 15, ESL 16, ESL 17, ESL 18, ESL 19, ESL 20, ESL 21, and / or ESL 22) to use for sending 440b responses to the network device 410. If wireless communication device 420b (e.g., ESL 12, ESL 13, ESL 14, ESL 15, ESL 16, ESL 17, ESL 18, ESL 19, ESL 20, ESL 21, and ESL 22) is addressed within the synchronization message, wireless communication device 420b (e.g., ESL 12, ESL 13, ESL 14, ESL 15, ESL 16, ESL 17, ESL 18, ESL 19, ESL 20, ESL21, and ESL 22) may respond (e.g., send 440b) in its corresponding response slot as indicated in the synchronization message.

[0091] For example, the synchronization message may instruct one or more wireless communication devices 420b (e.g., ESL 12, ESL 13, ESL 14, ESL 15, ESL 16, ESL 17, ESL 18, ESL 19, ESL 20, ESL 21, and / or ESL 22) to respond (e.g., transmit 440b) in a timely manner to a specified sequence (e.g., in a response time slot located every 0.625 ms after 5 ms has passed after the start of a subframe). For example, the sequence may indicate that the wireless communication device 420b (e.g., ESL 12) should respond in a response time slot at 17.5 ms, the wireless communication device 420b (e.g., ESL 13) should respond in a response time slot at 18.125 ms, the wireless communication device 420b (e.g., ESL 14) should respond in a response time slot at 18.75 ms, the wireless communication device 420b (e.g., ESL 15) should respond in a response time slot at 19.37, the wireless communication device 420b (e.g., ESL 16) should respond in a response time slot at 20 ms, the wireless communication device 420b (e.g., ESL 17) should respond in a response time slot at 20.625 ms, the wireless communication device 420b (e.g., ESL 18) should respond in a response time slot at 21.25 ms, and the wireless communication device 420b (e.g., ESL 19) should respond in a response time slot at 22. 19) should respond in the response time slot at 21.875 ms, wireless communication device 420b (e.g., ESL 20) should respond in the response time slot at 22.5 ms, wireless communication device 420b (e.g., ESL 21) should respond in the response time slot at 23.125 ms, and wireless communication device 420b (e.g., ESL 22) should respond in the response time slot at 23.75 ms.

[0092] After the wireless communication devices 420b (e.g., ESL 12, ESL 13, ESL 14, ESL 15, ESL 16, ESL 17, ESL 18, ESL 19, ESL 20, ESL 21, and ESL 22) have received 435b the PA containing the synchronization message from the network device 410, one or more of the wireless communication devices 420b (e.g., ESL 12, ESL 13, ESL 14, ESL 15, ESL 16, ESL 17, ESL 18, ESL 19, ESL 20, ESL 21, and ESL 22) may send 440b their responses within their respective response time slots according to a sequence specified within the synchronization message. After one or more wireless communication devices 420b (e.g., ESL 12, ESL 13, ESL 14, ESL 15, ESL 16, ESL 17, ESL 18, ESL 19, ESL 20, ESL 21, and / or ESL 22) have transmitted 440b their responses in their respective time slots, the network device 410 may receive 445b their transmitted responses in those designated response time slots. PAwR may then similarly continue for subsequent subframe times.

[0093] As previously mentioned, each access point (e.g., a master device) may have an associated channel map. A channel map is a list of frequency channels that the access point will utilize, or not utilize (e.g., if the frequency hopping sequence is modified), for communications with, for example, an ESL or other devices. An access point's channel map can be updated via a channel map update (CMU). A CMU is the process used to update (or change) an access point's current channel map (ChM) to a new channel map for that access point. During a CMU, the access point may send a synchronization message to the ESL to inform the ESL of the new channel map to be used for future communications with the access point.

[0094] In an ESL system, an access point (e.g., a master device) may send a synchronization message carried in an AUX_SYNC_IND (e.g., Auxiliary Synchronization Indication) on a periodic physical channel. In some cases, to coexist with a wireless local area network (WLAN) or to avoid noisy channels, the access point (e.g., a master device) may need to change the channel mapping. The access point (e.g., a master device) may change the channel mapping by performing a CMU using a CMU indication, which may be carried in the ACAD field of the AUX_SYNC_IND. The AUX_SYNC_IND may contain a Channel Map (ChM) field, which contains the future channel mapping (e.g., the new channel mapping) to which the PA sequence will switch, and an Immediate field, which is the future time (e.g., for a PeriodicEventCounter, which is an event counter for the PA sequence) to which the access point will switch using the future channel mapping (e.g., the new channel mapping). To ensure that the ESL (e.g., slave device) can successfully receive the CMU information, the access point (e.g., master device) can send AUX_SYNC_IND + CMU at least a certain number of times (e.g., at least six (6) times) for each group of ESL (e.g., 6*128 groups of ESL for PAwR).

[0095] In some examples, an ESL device and / or ESL system can perform angle-of-arrival (AoA)-based location determination (e.g., as previously described) based on a constant tone extension (CTE) field appended to another transmission. For example, the CTE can be appended to an existing transmission, such as a PA. Periodic advertisements that include the CTE may also be referred to herein as PA CTEs. Some AoA-based location determination tasks performed by the ESL device and / or ESL system can be based on receiving multiple PA CTEs (e.g., multiple PA CTs, each including a CTE field) from multiple PA transmitters. For example, ESL-based AoA location determination performed for triangulation, static, and / or mobile use cases may require the ESL (e.g., configured as an AoA receiver) to measure the PA CTEs from multiple different PA transmitters.

[0096] As previously mentioned, the systems and techniques described herein can be used to perform location determination based on PA synchronization. For example, these systems and techniques can be used to perform AoA-based location determination based on PA synchronization. In some examples, AoA-based location determination can be performed using one or more wireless communication devices (e.g., such as electronic shelf labels (ESLs) or other peripheral devices). In some cases, PA synchronization can be performed using an access point (AP) synchronization system. The AP synchronization system can be included in or provided as an ESL system, as described in more detail below.

[0097] Figure 5 is a signaling diagram illustrating an example of a periodic advertisement (PA) constant tone extension (CTE) transmission in a PA subframe 500 according to some examples. AP 510 may be associated with multiple wireless communication devices, such as electronic shelf label (ESL) devices (e.g., also referred to herein as "ESLs"). For example, AP 510 may be associated with a first ESL 514a (e.g., ESL1), a second ESL 514b (e.g., ESL2), a third ESL 514c (e.g., ESL3), and a fourth ESL 514d (e.g., ESL4). In some aspects, ESLs 514a-514d may be identical or similar to one another. ESLs 514a-514d (e.g., collectively referred to as ESLs 514) may be included in the same group associated with AP 510. For example, each ESL 514 may have the same group identifier, where the group identifier is associated with AP 510.

[0098] In some aspects, PA CTE transmission may be provided on a PA subframe 500 having a duration of 12.5 ms (eg, a PA interval), as described above with respect to Figure 4 In one illustrative example, the PA subframe 500 may include one or more subframe time slots. For example, the PA subframe 500 may include 10 time slots, each time slot having a duration of 1.25 ms (eg, a PA interval of 12.5 ms divided by 10 time slots).

[0099] PA subframe 500 may be a PAwR subframe associated with AP 510 and / or associated with one or more PAwR transmissions of AP 510. For example, in time slot 0, AP 510 may generate and transmit a PAwR transmission (e.g., shown as "Tx" in time slot 0). Based on the association between multiple ESLs 514 and AP 510, each of ESLs 514a-514d may receive a PAwR transmission from AP 510 (e.g., shown as a corresponding "Rx" in time slot 0 for each of ESLs 514a-514d). In one illustrative example, ESLs 514 may simultaneously receive the PAwR transmissions in time slot 0. For example, the PAwR transmissions may include synchronization information for AP 510, which ESLs 514 may use to establish and / or re-establish synchronization with AP 510 (e.g., to compensate for time drift since the last synchronization event or since the last receipt of synchronization information).

[0100] In one illustrative example, the PAwR transmission generated and sent by AP 510 in time slot 0 may be an AP_SYNC packet. In some cases, the AP_SYNC PAwR transmission may be sent at a time aligned with the start of the PAwR subframe 500. For example, AP 510 may send or broadcast the AP_SYNC packet at the beginning of time slot 0 (e.g., which may coincide with the start of the PAwR subframe 500). Based on receiving the AP_SYNC packet (or other PAwR transmission) from AP 510 in time slot 0, one or more ESLs 514 may later generate and send a response packet (e.g., using one of subsequent time slots 1-9 included in the same PAwR subframe 500 as the AP_SYNC packet). In some cases, ESLs 514 may send the response packet at a predetermined offset relative to the AP_SYNC packet. For example, the predetermined offset may be indicated by synchronization information included in the AP_SYNC packet. The synchronization information of the AP_SYNC packet may also include one or more device identifiers indicating the specific ESL 514 from which the AP 510 expects or requests a response.

[0101] like Figure 5 As shown, first ESL 514a, third ESL 514c, and fourth ESL 514d generate and send PAwR transmissions (e.g., response packets) based on receiving a PAwR transmission (e.g., an AP_SYNC packet) from AP 510 in time slot 0. PAwR transmissions from ESL 514 may be sent in one or more predetermined time slots of PAwR subframe 500. For example, three ESL PAwR response transmissions may be sent in time slots 4 and 5 of PAwR subframe 500.

[0102] Each ESL PAwR response transmission can be sent using a specific ESL response time slot (e.g., using a specific ERP time slot). For example, ESL 514a can send a PAwR response using the first ERP time slot included in PAwR subframe 500 time slot 4; ESL 514c can send a PAwR response using the second ERP time slot included in PAwR subframe 500 time slot 4; and ESL 514d can send a PAwR response using the third ERP time slot included in PAwR subframe 500 time slot 5. The ERP time slots can be different from the time slots of PAwR subframe 500. For example, PAwR subframe 500 can include 10 time slots and 11 ESL response time slots (e.g., ERPs). The 10 PAwR time slots can each last 1.25 ms, while the 11 ESL response time slots can each last 0.625 ms. Each ESL response time slot may additionally be associated with a start time of 5 ms from the edge of the PAwR subframe 500 (eg, the ESL response time slots may all have a start time no earlier than Figure 5In some aspects, the 11 ESL response time slots may overlap with or be included in each of PAwR time slots 4-9.

[0103] In one illustrative example, the systems and techniques described herein can be used to transmit (and receive) one or more PA CTEs for AoA-based position determination, where the PA CTEs are transmitted on subframes shared with one or more additional PA transmissions and / or PA sequences. For example, these systems and techniques can be used to transmit (and receive) one or more PA CTEs for AoA-based position determination. Figure 5 One or more AoA packets may be sent within a PAwR subframe 500 of the AP 510. In some aspects, the AoA protocol may be sent based on time synchronization between one or more (or all) of the AP 510 and the ESL 514. For example, based on time synchronization, the AoA PA CTE may be sent in a PAwR time slot that is not associated with or reserved for PAwR response transmissions (e.g., time slots 0-9).

[0104] For example, PAwR slots 4 and 5 may be reserved for PAwR response transmissions sent (or potentially sent) by ESL 514, and the systems and techniques may be used to use one or more (or all) of the remaining PAwR slots to send and receive PACTEs. For example, one or more slots included in first group 522 and / or one or more slots included in second group 526 may be used to send and receive these slots. In some aspects, multiple PACTEs may be sent and / or received in the same PAwR slot. For example, a given PAwR slot may include multiple sub-portions, where each of the multiple PACTEs sent / received in the PAwR slot utilizes a different sub-portion.

[0105] In one illustrative example, PA CTEs for AoA-based location determination can be scheduled onto multiple PA sequences. For example, each AoA Tx ESL and each AoA Rx ESL can form a corresponding PA sequence. In some aspects, the PA sequences associated with PA CTEs for AoA-based location determination using ESLs can be synchronized between the ESLs using a timing reference. For example, the timing reference can be a reference start time at which each Tx and Rx ESL begins transmitting or receiving the PA CTE, respectively. Additionally or alternatively, the timing reference can be provided by a network entity (e.g., AP 510) associated with each ESL and can be used to provide or determine the reference start time for each ESL.

[0106] In some examples, systems and techniques can utilize synchronization information to determine a PA CTE reference start time for an ESL and avoid collisions or conflicts with PAwR transmissions on the same PAwR subframe 500. For example, the synchronization information can be used to start corresponding PA sequences associated with the ESL and AoA-based position determination at a shared reference time, and can additionally be used to schedule PA CTE transmissions (e.g., on corresponding PA sequences) to avoid collisions or conflicts with PAwR transmissions in the same PAwR subframe 500, as described in greater depth below.

[0107] Figure 6 6 is a signaling diagram 600 illustrating an example of multiple time-synchronized PACTE transmissions between a time-synchronized network device and multiple wireless communication devices using PA subframes according to some examples. In one illustrative example, the network device may be an AP 610, and the multiple wireless communication devices may include ESLs 614a-614d. PACTE transmissions may be scheduled and / or synchronized based on using time synchronization information associated with the AP 610 and the ESLs 614a-614d as a common or shared time reference.

[0108] For example, multiple PA subframes may be used to transmit and receive PA CTE, including a first PA subframe 620, a second PA subframe 630, a third PA subframe 640, and so on. The PA subframes 620-640 may be Figure 5 5. The PA subframes 620-640 may be identical or similar to the PAwR subframe 500. For example, the PA subframes 620-640 may each have a duration of 12.5 ms. In some aspects, the PA subframes 620-640 may be included in multiple PA subframes of a PA frame. For example, a PA frame may include 128 PA subframes, each having a duration of 12.5 ms, such that the PA frame has a duration of 128*12.5 ms = 1.6 s.

[0109] The 12.5 ms PA subframe duration can be the same as the PA sub-event interval. For example, the 12.5 ms sub-event interval can be used to generate and send (e.g., by AP 610) a PAwR transmission (e.g., a PAwR transmission can be sent by AP 610 in each PA subframe). For example, a first PA subframe (e.g., a PAwR subframe) 620 can be associated with a first PAwR transmission 622, a second PA subframe (e.g., a PAwR subframe) 630 can be associated with a second PAwR transmission 632, a third PA subframe (e.g., a PAwR subframe) 640 can be associated with a third PAwR transmission 642, and so on.

[0110] In one illustrative example, the PAwR transmissions in each PA subframe (e.g., PAwR transmissions 622, 632, 642) can be synchronization messages or can include synchronization information. For example, the PAwR transmission can be an AP_SYNC packet sent by AP 610 to ESL 614. In some cases, AP 610 can generate and send an AP_SYNC packet at the beginning of each PA subframe (e.g., 620, 630, 640). Based on receiving the AP_SYNC packet in each PA subframe, ESL 614 can perform and / or maintain time synchronization with AP 610.

[0111] To perform AoA-based position determination, systems and techniques can determine synchronization information for forming one or more PA sequences associated with the ESL 614 and for transmitting / receiving a plurality of PA CTEs. For example, a PA CTE sequence can be formed (e.g., started) at a start time that is a fixed or predetermined offset from an existing PAwR transmission associated with the plurality of PA subframes 620, 630, 640.

[0112] For example, the first ESL 614a can be scheduled to transmit a first PACTE transmission 626 at a start time within the PA subframe 620 that is a fixed offset from a PAwR receive slot 625, also within the PA subframe 620. The first ESL 614a can use the PAwR receive slot 625 to receive an AP_SYNC packet 622 transmitted by the AP 610. In some aspects, the transmission start time associated with the first PACTE transmission 626 can be determined relative to a PAwR start time (e.g., a start transmission time of the AP_SYNC 622 and / or a start reception time of the PAwR receive slot 625). For example, the transmission start time associated with the first PACTE transmission 626 can be a fixed time offset from the start of the PA subframe 620 (e.g., based on the AP_SYNC transmitted and received at the start of the PA subframe 620). In some examples, the first ESL 614a can use the same fixed time offset to generate and send PA CTE transmissions in each of the PA subframes 620, 630, and 640. In such examples, the interval between consecutive PA CTEs sent by the first ESL 614a can be the same as the interval between consecutive PA subframes. For example, the interval between consecutive PA CTEs sent by a corresponding ESL among ESLs 614a-614d can be 12.5 ms.

[0113] The second ESL 614b is shown receiving an AP_SYNC (or other PAwR transmission) packet 632 at the beginning of the PA subframe 630 using a corresponding PAwR receive slot 635. Both the AP_SYNC 632 and the PAwR receive slot 635 can be aligned with the edge (e.g., the beginning) of the PA subframe 630. The second ESL 614b can generate and send a PACTE 636 using a fixed time offset from the PAwR sequence. The time offset associated with the PACTE 636 sent by the second ESL 614b can be different from the time offset associated with the PACTE 626 sent by the first ESL 614a. For example, the second ESL 614b may send the PACTE 636 using a larger time offset from the start of the PA subframe 630 so that the PACTE 636 is sent after the AP_SYNC 632 and the PACTE sent by the first ESL 614a (eg, such as the PACTE 626 sent using the first time offset from the PAwR sequence).

[0114] Similarly, the third ESL 614c is shown receiving AP_SYNC 642 at the beginning of the PA subframe 640 using a corresponding PAwR receive slot 645. Both the AP_SYNC 642 and the PAwR receive slot 645 can be aligned with the edge (e.g., the beginning) of the PA subframe 640. The third ESL 614c can generate and transmit a PACTE 646 using a fixed time offset from the PAwR sequence. The time offset used to transmit the PACTE 646 can be different from (e.g., greater than) the time offset used to transmit the PACTE 636 and can be different from (e.g., greater than) the time offset used to transmit the PACTE 626.

[0115] In some aspects, the first three ESLs 614a-614c can be configured as Tx ESLs for transmitting AoA PACTEs for AoA-based position determination as described herein. For example, the three ESLs 614a-614c can generate and transmit time-synchronized PACTEs that do not collide with each other and with existing PAs associated with PA subframes 620, 630, and 640 on the PAwR sequence.

[0116] The fourth ESL 614d can be configured as an Rx ESL to receive the AoA PACTEs sent by the Tx ESLs 614a-614c. For example, each Tx ESL 614a-614c can send a corresponding PACTE at a predetermined time within each PAwR subframe 620, 630, 640. The Rx ESL 614d can receive each corresponding PACTE at a corresponding scheduled time within each PAwR subframe. For example, the three AoA Tx ESLs 614a-c can send one PACTE per PAwR subframe (e.g., at Figure 6 In the example shown, the AoA Rx ESL 614d may receive a total of three PA CTEs per PAwR subframe. One or more position determinations may be generated based on AoA information or measurements determined from the PA CTEs received at the AoA Rx ESL 614d.

[0117] In one illustrative example, each ESL 614a-d can be associated with a corresponding PA sequence for transmitting or receiving a PA CTE. The PA sequence used to transmit and receive the PA CTE can be different from the PAwR sequence used to transmit and receive AP_SYNC packets and PAwR responses. For example, the AP_SYNC packets 622, 632, 642 and the corresponding PAwR receive slots 625, 635, 645 can be associated with the PAwR sequence of the AP 610, and each PA CTE can be transmitted and / or received using a PA CTE sequence different from the PAwR sequence of the AP 610.

[0118] In some aspects, each ESL can be associated with its own PA CTE sequence. For example, the first ESL 614a can jump into or form a first PA CTE sequence for transmitting the first PA CTE 626; the second ESL 614b can jump into or form a second PA CTE sequence for transmitting the second PA CTE 636; the third ESL 614c can jump into or form a third PA CTE sequence for transmitting the third PA CTE 646; and so on. In some aspects, the fourth ESL 614d (e.g., an AoA Rx ESL) can additionally or alternatively utilize its own PA CTE sequence to receive multiple PA CTEs transmitted by the AoA Tx ESLs 614a-c. In some aspects, the AoA Rx ESL 614d can track each independent PACTE sequence associated with the corresponding AoA Tx ESL 614a-c, e.g., based on the PACTE sequences associated with the AoA Tx ESLs 614a-c being independent but non-overlapping in time. By tracking each independent and non-overlapping PACTE sequence used to transmit multiple PACTEs, the AoA Rx ESL 614d can receive at least one PACTE transmission from each AoA Tx ESL in each PAwR subframe (e.g., 620, 630, 640).

[0119] In some respects, Figure 6 The example of depicts steady-state operation of an ESL system including AP 610 and ESLs 614a-d, where time synchronization has been established for scheduling and synchronizing transmission and reception of PACTEs. Figure 7 7 is a signaling diagram illustrating an example of establishing multiple time-synchronized PACTEs using PA subframes between a time synchronization network device and multiple wireless communication devices according to some examples. In one illustrative example, the network device may be an AP 710. The multiple wireless communication devices may include an AoA Tx ESL 712 for transmitting one or more PACTEs for AoA-based location determination, and may include an AoA Rx ESL 714 for receiving one or more PACTEs for AoA-based location determination. For example, the AoA Tx ESL 712 may generate and transmit packets received by the AoA Rx ESL 714. In some aspects, the AP 710 may communicate with Figure 6 The AP 610 shown is the same as or similar to the AoA Tx ESL 712. Figure 6 One or more of the AoA Tx ESLs 614a-c shown may be the same as or similar to the AoA Tx ESLs 614a-c, and / or the AoA Rx ESL 714 may be the same as or similar to the AoA Tx ESLs 614a-c shown. Figure 6The AoA Rx ESL 614d shown is the same or similar.

[0120] In one illustrative example, initial time synchronization can be performed using one or more AP_SYNC packets sent by AP 710. For example, AP 710 can generate and send corresponding AP_SYNC packets to a PACTE transmit-side device (e.g., AoA Tx ESL 712) and a PACTE receive-side device (e.g., AoA Rx ESL 714). As shown, AP 710 can generate and send an AP_SYNC packet 722 for ESL1 and can generate and send an AP_SYNC packet 732 for ESL2.

[0121] The AP_SYNC packets 722 and 732 may include synchronization information that may be used by the respective ESLs 712 and 714 to determine a reference time (e.g., a start time) for forming or otherwise jumping to one or more PA CTE sequences. For example, the AP_SYNC 722 of ESL1 may be used to determine a reference time and / or a start time for forming a PA CTE sequence for multiple PA CTE transmissions by the AoA Tx ESL 712. The AP_SYNC 724 of ESL2 may be used to determine a reference time and / or a start time for jumping to or joining the ESL1 PA CTE sequence to receive multiple PA CTE transmissions from the AoA Tx ESL 712 at the AoA Rx ESL 714.

[0122] In some aspects, for example, AoA Rx ESL 714 may jump directly to the ESL1 PACTE sequence based on determining timing information included in or indicated by AP_SYNC 732. In one illustrative example, AP_SYNC 722 and 732 may include or indicate first timing information and second timing information.

[0123] For example, the first timing information may be timing information associated with AP 710 and / or associated with a PAwR subframe in which the PA CTE is transmitted. In one illustrative example, the first timing information may include shared or common time reference information, such as syncInfo indicating a PAwR sequence in the PAwR subframe.

[0124] The second timing information may be timing information associated with the Tx and Rx ESLs used to perform AoA-based position determination. For example, the second timing information may be timing information associated with the AoA Tx ESL 712 and / or the AoA Rx ESL 714. In some aspects, the second timing information may include one or more parameters that may be used to enhance PAwRsyncInfo such that the ESLs 712, 714 may use the second timing information to determine PACTEsyncInfo. For example, PACTEsyncInfo may be used to form, jump to, or otherwise join one or more PACTE sequences associated with the AoA Tx and Rx ESLs. In some aspects, the AP_SYNC 722 received by the AoA Tx ESL 712 may include synchronization information that is the same or similar to the synchronization information included in the AP_SYNC 732 received by the AoA Rx ESL 714. For example, based on the Tx and Rx ESLs receiving the same synchronization information, one or more Tx ESLs may begin transmitting packets at a known time relative to one or more corresponding Rx ESLs. In one illustrative example, channel synchronization between the AoA Tx ESL and the AoA Rx ESL may be performed based on the ESLs receiving the same synchronization information from the AP 710 (eg, via AP_SYNC packets 722 , 732 , etc.).

[0125] In some aspects, the AP 710 may trigger an AoA ESL (e.g., AoA ESL 712) to begin transmitting the PACTE using an AoA Tx enable transmission 724. As shown, the AoA Tx enable 724 may be sent to the Tx ESL 712 simultaneously with the AP_SYNC packet 722. In some examples, the AoA Tx enable 724 may be included in or indicated by the AP_SYNC packet 722. In other examples, the AoA Tx enable 724 may be distinct from the AP_SYNC packet 722.

[0126] The AoA Tx Enable 724 may include timing information that may be used by the Tx ESL 712 to determine a start time for transmitting the plurality of PACTEs 726. For example, the Tx ESL 712 may use the timing information indicated by the AoA Tx Enable 724 to determine a transmission time offset 782. Figure 7The transmission offset ΔTx may be an offset relative to the Tx ESL 712 that receives the AoA Tx enable message 724 and / or may be an offset relative to the AP_SYNC 722 sent by the AP 710 (e.g., where the AP_SYNC 722 time and the AoA Tx enable 724 time may be the same).

[0127] The Rx ESL 714 may receive an AoA Rx Enable message 734 from the AP 710, which may be similar to the AoA Tx Enable message 724. For example, the AoA Tx Enable message 724 and the AoA Rx Enable message 734 may include the same timing or synchronization information for forming or jumping to a PACTE sequence. In one illustrative example, the AoA Rx Enable 734 may include timing information that may be used by the Rx ESL 714 to determine a start time for receiving (e.g., listening to) multiple PACTEs. For example, the Rx ESL 714 may use the timing information indicated by the AoA Rx Enable 734 to determine a receive time offset 784, which may be used to determine the start time of receiving (e.g., listening to) multiple PACTEs. Figure 7 The receive time offset ΔRx may be an offset relative to the Rx ESL 714 at which the AoA Rx enable message 734 is received, and / or may be an offset relative to the AP_SYNC 732 sent by the AP 710 (e.g., where the AP_SYNC 732 time and the AoA Rx enable 734 time may be the same).

[0128] In one illustrative example, the ΔTx time offset 782 and the ΔRx time offset 784 can be determined as a fixed offset plus a predetermined time slot increment. For example, the fixed offset can be a predetermined offset used by each Tx and Rx ESL. In some aspects, the fixed offset can be an offset relative to the edge (e.g., the start) of each PAwR subframe and / or can be an offset relative to the AP_SYNC packet (e.g., where the AP_SYNC packet time and the start of the PAwR subframe can be the same based on the alignment of the AP_SYNC packet with the PAwR subframe edge). In some aspects, the fixed offset can be an offset relative to the ESL at which the AoA Tx enable message 724 or the AoA Rx enable message 734 is received (e.g., where the Tx / Rx enable messages 724 / 734 can be associated with the same time as the corresponding AP_SYNC packets 722, 732).

[0129] A predetermined slot increment can be a specific time offset associated with a given ESL and can be used to combine multiple ESL PACTE sequences into a single PAwR subframe. For example, a first Transmitting ESL can utilize a predetermined slot increment of 0, causing the first Transmitting ESL to form its PACTE sequence after the fixed offset time has elapsed. A second Transmitting ESL can utilize a predetermined slot increment of 1, causing the second Transmitting ESL to form its PACTE sequence in the next slot (or jump to the first ESL's PACTE sequence). For example, a predetermined slot increment can indicate a specific slot within a given PAwR subframe that is scheduled for a given ESL to transmit or receive a PACTE. A slot increment of 0 can indicate that the ESL is scheduled to transmit or receive in the first slot after the fixed offset time has elapsed (e.g., waiting for the fixed offset to elapse); a slot increment of 1 can indicate that the ESL is scheduled to transmit or receive in the second slot after the fixed offset time has elapsed (e.g., waiting for the fixed offset to elapse and waiting for the first slot to elapse while the first ESL is transmitting or receiving). A timeslot increment of 2 may indicate that the ESL is scheduled to transmit or receive in a third timeslot after a fixed time offset has passed (e.g., waiting for the fixed offset to run, waiting for the first timeslot to run when the first ESL transmits or receives, waiting for the second timeslot to run when the second ESL transmits or receives), and so on.

[0130] In some aspects, during the establishment of a PACTE transmission (e.g., Figure 7 As shown, a ΔTxRx time offset 788 may be determined between the start time of the first AoA Tx ESL 712 transmitting the PA CTE 726 and the subsequent start time of the AoA Rx ESL 714 listening to (e.g., receiving) the PA CTE 726 (e.g., where the PA CTE 726 is received as a received PA CTE 739). For example, ΔTxRx may be determined as: ΔTxRx = (EventCounterAPSyncRx – EventCounterAPSyncTx)*1.6s – (GroupIDTx – GroupIDRx)*12.5ms.

[0131] Here, EventCounterAPSyncRx is an Rx event counter that increments once per PA interval (e.g., every 1.6 seconds), and EventCounterAPSyncTx is a Tx event counter that also increments once per PA interval (e.g., every 1.6 seconds). For example, the event counters may be the same as or similar to the paEventCounter included in or associated with a PA sequence (e.g., a PA CTE sequence, a PAwR sequence, etc., such as an ESL). EventCounterAPSyncRx may indicate the event counter value in the most recently received AP_SYNC at the Rx ESL 714, and EventCounterAPSyncTx may indicate the event counter value in the most recently received AP_SYNC at the Tx ESL 712. In some aspects, the AP_SYNC 722 sent from the AP 710 to the Tx ESL 712 may indicate the EventCounterAPSyncTx value. The AP_SYNC 732 sent from the AP 710 to the Rx ESL 714 may indicate the EventCounterAPSyncRx value. In some examples, the AP_SYNC 732 sent from the AP 710 to the Rx ESL 714 may also indicate the EventCounterAPSyncTx value most recently provided to each Tx ESL (e.g., one or more Tx ESLs) by the AP 710. Based on the AP_SYNC 732 indicating EventCounterAPSyncTx and EventCounterAPSyncRx, the Rx ESL 714 may determine a time offset ΔTxRx that indicates when to begin listening or otherwise receiving the PACTE 739.

[0132] For example, when the Tx ESL 712 and the Rx ESL 714 receive AP_SYNC packets 722 and 732, respectively, within the same PAwR interval, the two event counter values will be the same, and ΔTxRx = (0)*1.6s – (GroupIDTx – GroupIDRx)*12.5ms = (GroupIDTx – GroupIDRx)*12.5ms. Here, based on the Tx ESL 712 and the Rx ESL 714 having the same AP_SYNC event counter value, the ΔTxRx time offset between the start of the Tx ESL 712 transmitting the PACTE 726 and the start of the Rx ESL 714 listening / receiving the PACTE 739 can be determined as the number of 12.5ms subframes separating the two events. For example, GroupIDTx can indicate the group to which the AoA Tx ESL 712 belongs and can be used to determine the time slot number scheduled for the Tx ESL 712 within any given PAwR subframe. Similarly, GroupIDRx may indicate the group to which the AoA RxESL 714 belongs and may be used to determine the time slot number scheduled for the Rx ESL 714 within the PAwR subframe.

[0133] In some aspects, the Tx ESL 712 can adjust its internal clock to synchronize with the reference time or reference clock of the AP 710 once per PA interval (e.g., once every 1.6 seconds). For example, AP_SYNC 722 and AP_SYNC 732 can both be associated with a first PA interval, while AP_SYNC 742 and 752 are associated with a second PA interval. Based on the fact that AP_SYNC belongs to the same PA interval as AP_SYNC 722, and based on the fact that the Tx ESL 712 previously synchronized its internal clock with the reference time of the AP 710, AP_SYNC 732 does not trigger the Tx ESL 712 to adjust its internal clock or synchronize it with the AP 710.

[0134] Tx ESL 712 may receive AP_SYNC 742 in the second PA interval and may thus be triggered to adjust its internal clock to resynchronize with the reference time of AP 710. Tx ESL 712 may resynchronize with the reference time based on the timing or synchronization information included in AP_SYNC 742.

[0135] In some aspects, the Rx ESL 714 may also adjust its internal clock to resynchronize once per PA interval (e.g., once every 1.6 seconds) with the reference time of the AP 710. For example, the Rx ESL 714 and the Tx ESL 712 may both resynchronize with the reference time of the AP 710 (e.g., and thereby resynchronize with each other) at the beginning of a PA interval based on receiving an AP_SYNC (e.g., such as AP_SYNC 742) at the beginning of each PA interval.

[0136] In one illustrative example, Rx ESL 714 may also resynchronize or adjust its internal clock or timing once per subframe. For example, Rx ESL 714 may resynchronize with Tx ESL 712 at each PAwR subframe (e.g., once every 12.5 ms). In some cases, Rx ESL 714 may adjust its internal clock or timing information to the clock or timing information of Tx ESL 712 based on the timing or synchronization information indicated by the PACTE received by Rx ESL 714 from Tx ESL 712 in each PAwR subframe.

[0137] Figure 8 8 is a diagram illustrating an example of connectionless synchronization that can be performed to establish time-synchronized PA CTE transmissions between an AP and multiple ESLs and / or between various ESLs included in the multiple ESLs. For example, a PAwR hub 810 can send synchronization information to a PAwR peripheral 820 via clock synchronization 812. The PAwR hub 810 can be a device associated with a PAwR sequence that accepts registrations or associations from another device associated with the PAwR sequence. For example, the PAwR hub 810 can be an AP, and the PAwR peripheral 820 can be an ESL (e.g., such as an AoA Tx ESL). In some aspects, the PAwR peripheral 820 can be both a PAwR peripheral and a PA central device, such as in an example where an AoA Tx ESL registers or associates with an AP (e.g., thereby acting as a peripheral device for the PAwR sequence) while also accepting registrations or associations from an AoA Rx ESL on the PA CTE sequence (e.g., thereby acting as a central device for the PA CTE sequence).

[0138] The peripheral device 830 may be a PAwR peripheral device and a PA peripheral device. For example, the peripheral device 830 may be an AoARx ESL based PAwR peripheral device registered with or associated with an AP on a PAwR sequence, and a PA peripheral device registered with or associated with an AoA Tx ESL on a PA CTE sequence.

[0139] In one illustrative example, the PAwR hub 810 may perform clock synchronization 812 with the PAwR peripheral / PA hub 820 to establish timing synchronization. The PAwR peripheral / PA hub 820 may send a response 824 to the PAwR hub 810 indicating the timing information of the PA hub 820. Using the timing information of the PA hub 820 (e.g., received in the response 824), the PAwR hub 810 may perform timing synchronization 816 with the PAwR / PA peripheral 830. In one illustrative example, the timing synchronization 816 may indicate the timing information of the PA hub 820. For example, the timing synchronization information 816 may be used by the PAwR / PA peripheral 830 to derive the correct time and channel index to jump directly to a PA sequence (e.g., a PA CTE sequence) associated with the PA hub 820 (e.g., an AoA Rx ESL). In some aspects, the PAwR / PA peripheral 830 may use the timing synchronization information 8390 to perform connectionless synchronization with the PA hub 820. For example, based on determining the time and channel index for jumping directly to a PA sequence, the PAwR / PA peripheral device 830 can avoid performing timing synchronization, which otherwise might require scanning for ADV_EXT_IND PDUs 821 on the primary channel and then obtaining syncInfo from AUX_ADV_IND 823 on the secondary (e.g., legacy) channel. Based on receiving the timing synchronization information 816 of the PA center 820 (e.g., received from the PAwR center 810), the PA peripheral device 830 can perform connectionless synchronization with the PA center 820 and jump directly to a PA sequence (e.g., a PA CTE sequence) using the calculated synchronization information and AUX_SYNC_IND packets 825, 827.

[0140] In some aspects, systems and techniques may perform synchronization based on a syncInfo field associated with periodic advertisements. For example, the PA syncInfo field may include a synchronization packet offset. Systems and techniques may calculate the synchronization packet offset locally on both the PA center 820 and the PA peripheral 830 (e.g., the PAwR center 810) based on a common synchronization AP associated with both the PA center 820 and the PA peripheral 830. In some aspects, the synchronization packet offset may be determined based on a common synchronization offset of the PAwR sequence of the PAwR center 810 and based on a configurable offset associated with the PA center 820 or the PA peripheral 830 (e.g., such as a slot index assigned by the AP / PAwR center to a specific ESL (e.g., PAwR peripheral, PA center, PA peripheral) within each PAwR subframe.

[0141] In some examples, the PA syncInfo field may include an interval. These systems and techniques may determine the interval information based on configuration information provided by the PAwR center 810 (e.g., an AP). The interval information may be selected to align the PA sequence (e.g., AoA PA CTE) with an existing PAwR sequence of the PAwR center 810.

[0142] In some examples, the PA syncInfo field can include a channel map. The systems and techniques can obtain the channel map from a PAwR sequence of a commonly synchronized AP (eg, PAwR Center 810).

[0143] In some examples, the PA syncInfo field may include an access address (AA). The access address may be associated with or indicate a specific PA sequence. In some aspects, systems and techniques may determine the access address by adding an ESL identifier (EID) to the access address obtained from the commonly synchronized PAwR sequence.

[0144] In some examples, the PA syncInfo field may include the same CRCInit as the CRCInit associated with the commonly synchronized PAwR sequence (eg, the same CRCInit of the syncInfo from the AP / PAwR Center 810).

[0145] In some examples, the PA syncInfo field can include an event counter, as described above. The event counter field can contain the value of the paEventCounter associated with the AUX_SYNC_IND packet described by the syncInfo field. The paEventCounter can be a 16-bit value that increments by one for each PA interval (e.g., regardless of whether an AUX_SYNC_IND PDU is actually transmitted). The paEventCounter can be used to determine the hopping frequency sequence (HFS). In one illustrative example, the systems and techniques described herein can reinitialize the event counter field to zero based on a command from the ESL Tx side. A matching value can be determined for the calculated synchronization time based on the paEventCounter of the common PAwR sequence that triggers the transmission and reception of the new PA (e.g., AoAPA CTE) and further based on the group IDs of the Tx and Rx ESLs.

[0146] In one illustrative example, systems and techniques can perform AoA-based position determination using multiple PACTEs transmitted by multiple AoA Tx ESLs using one PA sequence. For example, the PACTEs transmitted by each Tx ESL in the multiple ESLs can be combined onto a single PA sequence, as described in more depth below.

[0147] Figure 9 is a signaling diagram illustrating an example of time-synchronized PA CTE transmissions using multiple ESLs sent over a combined periodic advertisement sequence according to some examples. The AP 910 may be configured to transmit PAwR signals over a PAwR sequence (eg, over multiple PAwR subframes) in accordance with the above description of the PAwR signaling scheme. Figure 5 The AP 510 shown in Figure 6 The AP 610 and / or Figure 7 7. The AP 910 may transmit one or more AP_SYNC packets (or other PAwR transmissions) in the same or similar manner as described for the AP 710 shown in FIG. For example, the AP 910 may transmit an AP_SYNC 922 at the beginning of a first PAwR subframe 920, may transmit an AP_SYNC 932 at the beginning of a second PAwR subframe 930, may transmit an AP_SYNC 942 at the beginning of a third PAwR subframe 940, and so on.

[0148] The AP_SYNC packets 922, 932, and 942 may be the same or similar to those described above. For example, the AP_SYNC packets may include or indicate timing and / or synchronization information for synchronizing multiple Tx ESLs 914 to transmit one or more PACTEs for AoA-based location determination. The multiple PACTEs may be received and measured by one or more Rx ESLs, such as Rx ESL 924. Rx ESL 924 may additionally receive one or more AP_SYNC packets from AP 910 and / or may receive or otherwise obtain the same timing and / or synchronization information received by Tx ESL 914 for synchronizing and scheduling PACTEs.

[0149] As mentioned above about Figures 5 to 7 As described above, in some examples, systems and techniques can use a corresponding PA sequence for the PA CTE sent by each corresponding Tx ESL. Figure 8In the example shown in FIG. 1 , seven Tx ESLs 914 can transmit a corresponding set of seven PA CTEs using seven PA sequences. In one illustrative example, the PA CTEs transmitted by multiple (or all) Tx ESLs 914 can be combined onto a single PA sequence. For example, each Tx ESL 914 can be associated with or included in the same PA CTE sequence, wherein each Tx ESL 914 transmits at a reduced rate relative to the PA CTE sequence rate.

[0150] For example, each PAwR subframe 920, 930, 940 may include multiple time slots. As shown, each PAwR subframe may include 10 equally sized time slots, as shown by time slots 0-9 of PAwR subframe 920. In some aspects, the time slots of PAwR subframe 920 may be the same as those described above for Figure 5 The time slots of the PAwR subframe 500 are the same as or similar to those described in the PAwR subframe 500. Each Tx ESL 914 can be associated with or scheduled to a specific one of the ten time slots in each PAwR subframe so that each Tx ESL 914 can transmit a PA CTE in each PAwR subframe without colliding with an existing PAwR transmission or with another PA CTE transmission.

[0151] For example, in a PAwR subframe 920, the AP 910 may transmit an AP_SYNC 922 in slot 0, and ESL 1 may receive the AP_SYNC 922 in a corresponding PAwR receive slot 925. ESL 1 may transmit a PACTE in slot 1 and, in some aspects, may initialize or form a PACTE sequence that each of the Tx ESLs 914 will use to transmit their respective PACTEs. In some examples, Tx ESL 1 may form a combined PACTE sequence based on timing and / or synchronization information included in the AP_SYNC 922 from the AP 910.

[0152] In time slot 2, Tx ESL 2 may transmit a PACTE, and in time slot 3, Tx ESL 3 may transmit a PACTE. Time slots 4 and 5 may be reserved for PAwR transmissions from AP 910 to ESLs 914 and / or 924, and for PAwR reply transmissions (e.g., such as PAwR reply 926) from ESLs 914 and / or 924 to AP 910. For example, the reservation of time slots 4 and 5 in each PAwR subframe may be the same as described above for PAwR. Figure 5The PAwR subframe 500 depicts the same or similar retention of slots 4 and 5. In slot 6, Tx ESL 4 may send its PA CTE; in slot 7, Tx ESL 5 may send its PA CTE; in slot 8, Tx ESL 6 may send its PA CTE; and in slot 9, Tx ESL 7 may send its PA CTE.

[0153] In each instance of a PACTE transmission by one of the Tx ESLs 914, the corresponding Tx ESL can use the same PACTE sequence. For example, as described above, the first Tx ESL 1 can form a combined PACTE sequence in slot 1 based on the syncInfo and / or additional timing information indicated by the AP_SYNC 922. In slot 2, the second Tx ESL 2 can use the same syncInfo and additional timing information as the first Tx ESL 1 (e.g., based on the second Tx ESL 2 receiving the same information in the AP_SYNC packet sent by the AP 910) to determine the time and channel index for directly jumping to the combined PACTE sequence. Similarly, the remaining Tx ESLs can perform the same process to directly jump to the combined PACTE sequence in their respective PAwR subframe slots, again using the time and channel index information determined at the Tx ESL based on the syncInfo and additional PACTE sequence parameters indicated in the AP_SYNC packet from the AP 910.

[0154] In each time slot scheduled for PA CTE transmission (e.g., time slots 1-3 and 6-9), the Rx ESL 924 may perform the same or similar process, using the syncInfo indicated in the AP_SYNC packet from the AP 910 and the attached PA CTE sequence parameters to determine the time and channel index information to jump directly to the combined PA CTE sequence to listen to or receive the corresponding PA CTE transmission from each Tx ESL 914.

[0155] In some aspects, each of the Tx ESL 914 and the Rx ESL 924 can listen to the AP (e.g., AP 910) for its own group and response. The Rx ESL 924 can maintain a state machine for each PA CTE sequence. For example, when each Tx ESL transmits a PA CTE on its own PA CTE sequence, the Rx ESL 924 may need to maintain seven different state machines to determine when to listen to / receive the corresponding PA CTE. Based on combining the PA CTE transmissions of the Tx ESLs 914 into a single combined PA CTE sequence, the Rx ESL 914 can maintain a single state machine for receiving PA CTE transmissions from multiple Tx ESLs 914 on the combined PA CTE sequence.

[0156] In one illustrative example, a combined PA CTE sequence can be implemented based on access address information of the combined PA CTE sequence and slot index information indicating a specific time slot (e.g., a time slot in the seven available time slots for PA CTE transmission in each PAwR subframe, with the remaining three time slots reserved for PAwR) that is allocated or scheduled to each corresponding Tx ESL of up to seven Tx ESLs on the combined PA CTE sequence. For example, the slot index information can be used by each Tx ESL 914 to determine the correct EventCounter information, assuming that the combined PA CTE sequence has a PA interval of 1.25 ms.

[0157] For example, by transmitting at 1 / 10 of the combined PA sequence rate, a 1.25 ms PA interval can be based on each Tx ESL 914 using the combined PA CTE sequence. For example, the combined PA sequence rate can be the same as the 12.5 ms PAwR subframe interval. Because each Tx ESL 914 can be configured to transmit on only one of the 10 total subframe slots, each Tx ESL 914 can transmit at 12.5 ms / 10 = 1.25 ms (e.g., 1 / 10 of the combined PA sequence rate).

[0158] In some aspects, the slot index information used to implement the combined PACTE sequence can indicate to each Tx ESL 914 a specific subframe slot in which the Tx ESL 914 is scheduled to transmit the PACTE by directly jumping onto the combined PACTE sequence. As described above, each Tx ESL 914 can use the slot index information to determine the correct event counter information, wherein the event counter information can be used to maintain synchronization between the Tx ESL 914, the Rx ESL 924, and the AP 910.

[0159] In one illustrative example, the Tx ESL 914 can operate at an increased baseline rate to account for a 10-fold reduction in operating rate when transmitting on a combined PACTE sequence. For example, when each Tx ESL 914 is associated with an operating rate that is 1 / 10 of the combined PACTE sequence rate, the Tx ESL 914 can utilize an increased baseline rate that is increased by a factor of 10. For example, the Tx ESL 914 can have an increased baseline rate of 800 Hz (e.g., a 10-fold increase relative to a baseline rate of 80 Hz). When the baseline rate of the Tx ESL 914 is reduced by a factor of 10, the operating rate of the Tx ESL 914 on the combined PACTE sequence can be maintained at 80 Hz (e.g., rather than being reduced to 8 Hz, which would occur if the baseline rate were not increased by a corresponding factor of 10).

[0160] In some aspects, from the perspective of each Tx ESL 914 operating on the combined PA CTE sequence, the Tx ESL 914 transmits a complete subframe of PA CTE transmission during its assigned time slot (e.g., a Tx ESL of 80 Hz for a complete subframe and a Tx ESL of 800 Hz for 1 / 10 of a complete subframe (e.g., one time slot) may be the same from the perspective of the Tx ESL).

[0161] From the perspective of the Rx ESL 924, by combining the respective PA CTE transmissions associated with each Tx ESL 914 in a given PAwR subframe (e.g., PAwR subframe 920), the combined PA CTE transmission may appear the same as a single PACTE sequence transmission, but with a PA spacing reduced by a factor of 10 (e.g., the combined PA CTE sequence transmission at the Rx ESL 924 may be the same as or similar to a single PA CTE sequence transmission, but with a PA spacing of 1.25 ms instead of 12.5 ms).

[0162] Figure 10 is a signaling diagram illustrating an example of establishing time-synchronized PACTE transmissions by multiple Tx ESLs using a combined PA sequence according to some examples. In some aspects, the combined PA CTE sequence (e.g., as described above with reference to Figure 9The AP may then share the access address and / or other synchronization information of the combined PA CTE sequence determined by the first AoA Tx ESL with one or more additional AoA Tx ESLs, wherein the additional AoA Tx ESLs may jump directly to the combined PA CTE sequence using the synchronization information generated by the first Tx ESL and sent by the AP (to the additional Tx ESLs).

[0163] For example, the AP 1010 may be associated with and / or synchronized with a first Tx ESL 1020, a second Tx ESL 1030, and an Rx ESL 1040. The AP 1010 may send an AoA Tx enable message to the first Tx ESL 1020, which may be the first Tx ESL scheduled to transmit in a given PAwR subframe. The AoA Tx enable message may indicate timing and / or synchronization information associated with transmission on a PA CTE sequence. For example, the AoA Tx enable message may include a timeslot index assigned by the AP 1010 to the first Tx ESL 1020, may include an EID_Tx field (e.g., a device ID of the Tx ESL 1020), may include an access address field, and may include an event counter field. In some aspects, an AoA Tx enable message sent to a first Tx ESL (eg, such as the first Tx ESL 1020 ) of a plurality of Tx ESLs may include a valid slot index value and invalid values for the EID_Tx, access address, and event counter fields.

[0164] Upon receiving an AoA Tx Enable message with invalid values for the EID_Tx, Access Address, and Event Counter fields, the Tx ESL may determine that it is the first Tx ESL associated with the PA CTE sequence. Based on being the first Tx ESL in the PA CTE sequence, Tx ESL 1020 may examine the parameters included in the AoA Tx Enable message, calculate PA timing information used to form the PA CTE sequence, and generate additional information associated with the PA CTE sequence. In some aspects, the information generated by the first Tx ESL 1020 may correspond to the value of the invalid field in the AoA Tx Enable message received from AP 1010.

[0165] The first Tx ESL 1020 may send a response to the AP 1010 indicating PA parameters determined or otherwise generated by the first Tx ESL 1020. For example, the first Tx ESL 1020 may send a response to the AP 1010 indicating PA parameters for joining a PA CTE sequence to be formed by the first Tx ESL 1020.

[0166] The first Tx ESL 1020 may begin the PA CTE sequence using the PA parameters previously determined by the first Tx ESL 1020. In some aspects, the first Tx ESL may use multi-step increments (eg, 10 steps each) for an event counter associated with the PA CTE sequence.

[0167] The AP 1010 may send an AoA configuration to the Rx ESL 1040, wherein the AoA configuration includes the PA parameters determined by the first Tx ESL 1020. The AP 1010 may additionally send an AoA Rx enable message including the device address of the first Tx ESL 1020 to the Rx ESL 1040.

[0168] The Rx ESL 1040 may calculate the correct PA timing and PA information to jump directly to the PA CTE sequence initiated from the first Tx ESL 1020. For example, the Rx ESL 1040 may use the PA CTE sequence configuration parameters determined by the first Tx ESL 1020 and sent to the Rx ESL 1040 via an AoA configuration message from the AP 1010 to calculate the correct PA timing and PA information for jumping to the combined PA CTE sequence.

[0169] The Rx ESL 1040 can use the calculated PA timing and PA information to establish synchronization with the first Tx ESL 1020 and can monitor the combined PA CTE sequence at 800 Hz using the customized PA interval (e.g., as described above). After establishing synchronization with the first Tx ESL 1020, the Rx ESL 1040 can begin capturing packets sent by the first Tx ESL 1020 on the combined PA CTE sequence (e.g., PA CTE).

[0170] The AP 1010 may send an AoA Tx enable message to the second Tx ESL 1030, which may be the same or similar to the AoA Tx enable message previously sent to the first Tx ESL 1020. In some examples, the AoA Tx enable message sent by the AP 1010 to the second Tx ESL 1030 may be the same as the AoA Tx enable message to the first Tx ESL 1020, with only the timeslot index information changed. In one illustrative example, the AoA Tx enable message sent by the AP 1010 to the second Tx ESL 1030 may include a unique timeslot index assigned or scheduled to the second Tx ESL 1030 (e.g., by the AP 1010), and may also include the same EID_Tx, access address, and event counter information determined by the first Tx ESL 1020 and received by the AP 1010 in a response message sent by the first Tx ESL 1020 in response to the AoA Tx of the AP 1010.

[0171] The second Tx ESL 1030 may use the corresponding AoA Tx Enable message (e.g., and the parameters included therein) from the AP 1010 to calculate PA timing and other PA information in order to jump directly into or form the combined PA CTE sequence initiated by the first Tx ESL 1020. The second Tx ESL 1030 may send a response message to the AP 1010 indicating the parameters sent by the AP 1010 and received by the second Tx ESL 1030. The second Tx ESL 1030 may use the calculated PA timing and other PA information to start the combined PA CTE sequence initiated by the first Tx ESL 1020. The second Tx ESL 1030 may use multiple increments of the event counter (e.g., 10 steps each time) to send one or more PACTEs over the combined PA CTE sequence.

[0172] Figure 11 is a flow chart illustrating an example of a process 1100 for wireless communication. The process 1100 may be performed by a wireless communication device (e.g., such as an electronic shelf label (ESL) device, an active BLE tracker, etc.) or implemented by a component or system thereof (e.g., a chipset). The operations of the process 1100 may be implemented as a processor on one or more processors (e.g., Figure 13 The software components are executed and run on the processor 1310 or other processors of the wireless communication device. In addition, for example, the transmission and reception of signals by the wireless communication device in the process 1100 may be implemented through one or more antennas and / or one or more transceivers (eg, wireless transceivers).

[0173] In some aspects, process 1100 may be performed by an AoA Tx ESL device, as described above with respect to Figures 5 to 10 As stated.

[0174] At block 1102, process 1100 includes receiving synchronization information associated with a first set of periodic advertisements (PAs) from a network entity. For example, the network entity may be an access point (AP), such as Figure 1 AP 110, Figure 4 AP 410, Figure 5 AP510, Figure 6 AP 610, Figure 7 AP 710, Figure 9 AP 910 and / or Figure 10 AP 1010. In some cases, the network entity may communicate with Figure 1 The management entity 130 is the same as or similar to, and / or can be the same as Figure 8 The PAwR center 810 is the same or similar.

[0175] In some examples, process 1100 may be performed by a wireless communication device for wireless communication. For example, the wireless communication device may be an electronic shelf label (ESL) including Figures 4-10 In some cases, as described above, the wireless communication device may be an AoA Tx ESL. In some examples, the wireless communication device may be a PAwR peripheral device / PA central device, such as Figure 8 PAwR peripheral device / PA central device 820. In some examples, the wireless communication device can be a PAwR peripheral device / PA peripheral device, such as Figure 8 PAwR peripheral device / PA peripheral device 830.

[0176] In some examples, the first set of PAs includes a periodic advertisement with response (PAwR) sequence associated with a network entity. In some aspects, the synchronization information is included in an access point synchronization (AP_SYNC) packet. For example, the synchronization information may be included in Figure 6 In one or more of the AP_SYNC packets 622, 632, 642; may be included Figure 7 In one or more of the AP_SYNC packets 722, 732, 742, 753; may be included Figure 9 In one or more of the AP_SYNC packets 922, 929, 932, 939, 942, 949; etc. In some aspects, the synchronization information may be included in a PAwR transmission in each of a plurality of PA subframes associated with the network entity and / or wireless communication device. For example, the synchronization information may be included in the first PAwR transmission in each of a plurality of PA subframes, such as Figure 6 、 Figure 7and / or Figure 9 The PA (eg, PAwR) subframe shown in FIG.

[0177] At block 1104, process 1100 includes determining a first time offset from a reference time based on the synchronization information, where the reference time is associated with synchronization of a plurality of wireless communication devices, including the wireless communication device. For example, the reference time may be a time associated with transmission of an AP_SYNC packet from a network entity (e.g., an AP). In some cases, the synchronization time may be determined as the sum of the reference time and a first time offset that is a multiple of a predetermined time offset interval. The first time offset may be a specific time offset associated with the wireless communication device (e.g., an AoA Tx ESL).

[0178] In some cases, information associated with a predetermined time offset interval is received from a network entity, and the predetermined time offset interval has a length that is the same as a length of a sub-portion of a PAwR subframe. For example, a PAwR subframe may be used by the network entity to transmit one or more PAs from a first set of PAs. In some examples, the synchronization time may be determined as the sum of a reference time and a first time offset, where the first time offset is a multiple of the predetermined time offset interval, where the predetermined time offset interval is an integer multiple of a sub-portion (e.g., a sub-interval) of a PA (e.g., PAwR) subframe. For example, the predetermined time offset interval may be 1.25 ms, representing one of ten equally sized sub-portions (e.g., sub-intervals) of a 12.5 ms PAwR subframe.

[0179] In some examples, a subframe includes a plurality of non-overlapping time slots including a subset of reserved time slots for PAwR responses and a subset of non-reserved time slots. For example, the subframe may be Figure 5 The PAwR subframe 500 is the same or similar and may include multiple non-overlapping 1.25 ms time slots, such as Figure 5 In some cases, the subset of reserved slots for PAwR responses may be Figure 5 The reserved time slots Slot 4 and Slot 5 depicted in FIG are the same or similar, and a subset of the non-reserved time slots may be the same as Figure 5 The non-reserved time slots 522 and / or 526 are the same or similar. In some aspects, each PA in the second set of PAs may transmit using a particular time slot in the subset of non-reserved time slots. In some examples, the subset of reserved time slots includes a plurality of AP_SYNC response time slots, the plurality of AP_SYNC response time slots and the reserved time slots being associated with different durations. In some cases, the plurality of reserved AP_SYNC response time slots includes at least three AP_SYNC response time slots and / or includes at least three ESL response time slots, such as Figure 5 Those depicted in .

[0180] At block 1106, process 1100 includes transmitting a second set of PAs at a synchronization time based on the reference time and the first time offset, each PA in the second set of PAs including a constant tone extension (CTE). For example, the second set of PAs may include a CTE sequence of PAs associated with the wireless communication device (e.g., an AoA Tx ESL). In some cases, the synchronization time may be determined as the sum of multiples of the reference time and a predetermined time offset interval. For example, the reference time may be an AP_SYNC time used to synchronize an AP clock (e.g., a network entity clock) with respective clocks of a plurality of AoA Tx ESLs and / or one or more AoA Rx ESLs.

[0181] In some cases, each PA (e.g., each PA CTE) in the second set of PAs may transmit using a specific time slot in the subset of non-reserved time slots. For example, a first AoA Tx ESL may transmit a PA CTE using a first time slot (e.g., a reference time plus a first offset specific to the first AoA Tx ESL); a second AoA Tx ESL may transmit a PA CTE using a second time slot (e.g., the same reference time plus a second offset specific to the second AoA Tx ESL); and so on.

[0182] In some aspects, a wireless communication device may determine one or more parameters associated with forming a PA sequence (e.g., a PA CTE sequence). For example, the one or more parameters may be based on a slot index included in synchronization information. The wireless communication device may send the one or more parameters to a network entity and may use the one or more parameters to form a PA sequence. The wireless communication device (e.g., an AoA Tx ESL) may use the PA sequence (e.g., the PA CTE sequence) to transmit a second set of PA CTEs. In some aspects, the network entity may generate synchronization information based on the one or more parameters and may send the generated synchronization information to an additional AoA Tx ESL also associated with the network entity (e.g., associated with a PAwR sequence of the network entity (e.g., an AP)).

[0183] In some cases, the first time slot of the PACTE sequence is associated with a second set of PACTEs. The second time slot of the PACTE sequence may be associated with a set of additional PACTEs transmitted by a second wireless communication device (e.g., a second AoA Tx ESL) on the PACTE sequence. In some cases, one or more parameters associated with forming the PACTE sequence may be determined by the wireless communication device (e.g., the AoA Tx ESL) based on synchronization information including invalid values for one or more predetermined fields. In some cases, the one or more predetermined fields may include one or more of a group ID field, an access address field, or an event counter field.

[0184] Figure 12 1 is a flow chart illustrating an example of a process 1200 for wireless communication. The process 1200 may be performed by a network entity (e.g., such as a ME) and / or a network device (e.g., such as an AP) or a component or system thereof (e.g., a chipset). The operations of the process 1200 may be implemented as a processor on one or more processors (e.g., Figure 13 The software components executed and run on the processor 1310 or other processors of the wireless communication device. In addition, for example, the transmission and reception of signals by the wireless communication device in the process 1200 may be implemented through one or more antennas and / or one or more transceivers (e.g., wireless transceivers).

[0185] In some aspects, process 1200 may be performed by an AoA RX ESL device, such as described above with respect to Figures 5-10 Describes one or more AoA Rx ESL devices.

[0186] At block 1202, process 1200 includes receiving synchronization information associated with a first set of periodic advertisements (PAs) from a network entity. For example, the network entity may be an access point (AP), such as Figure 1 AP 110, Figure 4 AP 410, Figure 5 AP510, Figure 6 AP 610, Figure 7 AP 710, Figure 9 AP 910 and / or Figure 10 AP 1010. In some cases, the network entity may communicate with Figure 1 The management entity 130 is the same as or similar to, and / or can be the same as Figure 8 The PAwR center 810 is the same or similar.

[0187] In some examples, process 1100 may be performed by a wireless communication device for wireless communication. For example, the wireless communication device may be an electronic shelf label (ESL) including Figures 4-10In some cases, as described above, the wireless communication device may be an AoA Rx ESL. In some examples, the wireless communication device may be a PAwR peripheral device / PA central device, such as Figure 8 PAwR peripheral device / PA central device 820. In some examples, the wireless communication device can be a PAwR peripheral device / PA peripheral device, such as Figure 8 PAwR peripheral device / PA peripheral device 830.

[0188] In some examples, the first set of PAs includes a periodic advertisement with response (PAwR) sequence associated with a network entity. In some aspects, the synchronization information is included in an access point synchronization (AP_SYNC) packet. For example, the synchronization information may be included in Figure 6 In one or more of the AP_SYNC packets 622, 632, 642; may be included in Figure 7 In one or more of the AP_SYNC packets 722, 732, 742, 753; may be included in Figure 9 In one or more of the AP_SYNC packets 922, 929, 932, 939, 942, 949; etc. In some aspects, the synchronization information may be included in a PAwR transmission in each of a plurality of PA subframes associated with the network entity and / or wireless communication device. For example, the synchronization information may be included in the first PAwR transmission in each of a plurality of PA subframes, such as Figure 6 、 Figure 7 and / or Figure 9 The PA (eg, PAwR) subframe shown in FIG.

[0189] At block 1204, process 1200 includes determining a first time offset from a reference time based on the synchronization information, where the reference time is associated with synchronization of multiple wireless communication devices, including the wireless communication device. For example, the reference time may be a time associated with the transmission of an AP_SYNC packet from a network entity (e.g., an AP). In some examples, the reference time is associated with synchronization of multiple AoA Tx ESLs, one or more AoA Rx ESLs, and / or the network entity (e.g., an AP). For example, the AP_SYNC packet may be used to synchronize an AP clock with corresponding clocks of multiple AoA Tx ESLs and one or more AoA Rx ESLs. In some cases, additional synchronization may be performed periodically between one or more AoA Rx ESLs (e.g., the wireless communication device including process 1200) and the multiple AoA Tx ESLs. In some cases, the synchronization time may be determined as the sum of the reference time and a first time offset that is a multiple of a predetermined time offset interval. The first time offset may be a specific time offset associated with the wireless communication device (e.g., an AoA Tx ESL).

[0190] In some cases, information associated with a predetermined time offset interval is received from a network entity, and the predetermined time offset interval has a length that is the same as a length of a sub-portion of a PAwR subframe. For example, a PAwR subframe may be used by the network entity to transmit one or more PAs from a first set of PAs. In some examples, the synchronization time may be determined as the sum of a reference time and a first time offset, where the first time offset is a multiple of the predetermined time offset interval, where the predetermined time offset interval is an integer multiple of a sub-portion (e.g., a sub-interval) of a PA (e.g., PAwR) subframe. For example, the predetermined time offset interval may be 1.25 ms, representing one of ten equally sized sub-portions (e.g., sub-intervals) of a 12.5 ms PAwR subframe.

[0191] In some examples, a subframe includes a plurality of non-overlapping time slots including a subset of reserved time slots for PAwR responses and a subset of non-reserved time slots. For example, the subframe may be Figure 5 The PAwR subframe 500 is the same or similar and may include multiple non-overlapping 1.25 ms time slots, such as Figure 5 In some cases, the subset of reserved slots for PAwR responses may be Figure 5 The reserved time slots Slot 4 and Slot 5 depicted in FIG are the same or similar, and a subset of the non-reserved time slots may be the same as Figure 5The non-reserved time slots 522 and / or 526 are the same or similar. In some aspects, the wireless communication device (e.g., AoA Rx ESL) can use a specific time slot in the subset of non-reserved time slots to receive each PA in the second set of PAs. In some examples, the subset of reserved time slots includes a plurality of AP_SYNC response time slots, the plurality of AP_SYNC response time slots and the reserved time slots being associated with different durations. In some cases, the plurality of reserved AP_SYNC response time slots includes at least three AP_SYNC response time slots and / or includes at least three ESL response time slots, such as Figure 5 Those depicted in .

[0192] At block 1206, process 1200 includes receiving a second set of PAs from a second wireless communication device among the plurality of wireless communication devices at a synchronization time based on the first time offset and the reference time, each PA in the second set of PAs including a constant tone extension (CTE). For example, the wireless communication device of process 1200 may be an AoA Rx ESL and the second wireless communication device may be an AoA Tx ESL. For example, the wireless communication device of process 1200 may be a wireless communication device connected to Figure 6 AoA Rx ESL 614d, Figure 7 AoARx ESL 714 Figure 9 AoA Rx ESL 924 and / or Figure 10 The AoA Rx ESL 1040 may be one or more identical or similar AoA Rx ESLs.

[0193] The second set of PAs may include PA CTE sequences associated with one or more AoA Tx ESLs that are different from the AoA Rx ESLs of process 1200 and included in the same plurality of wireless communication devices as the AoA Rx ESLs of process 1200 (e.g., associated with the same network entity or AP). In some cases, a synchronization time for the second wireless communication device may be determined as a sum of corresponding multiples of a same reference time and a predetermined time offset interval (e.g., corresponding multiples for each respective AoA Tx ESL). For example, the reference time may be an AP_SYNC time used to synchronize an AP clock (e.g., a network entity clock) with the respective clocks of the plurality of AoA Tx ESLs and / or the one or more AoA Rx ESLs.

[0194] In some cases, each PA (e.g., each PA CTE) in the second set of PAs may be received using a specific time slot in the subset of non-reserved time slots. For example, a first AoA Tx ESL may use a first time slot (e.g., a reference time plus a first offset specific to the first AoA Tx ESL) to transmit the PA CTE, and the AoA Rx ESL of process 1200 may use the first time slot to receive the PA CTE; a second AoA Tx ESL may use a second time slot (e.g., the same reference time plus a second offset specific to the second AoA Tx ESL) to transmit the PA CTE, and the AoA Rx ESL of process 1200 may use the second time slot to receive the PA CTE; and so on.

[0195] In some aspects, the wireless communication device may determine a second time offset from the reference time based on synchronization, the second time offset comprising a second multiple of the predetermined time offset interval that is different from the first multiple. For example, the first time offset may be a multiple n=1 of a 1.25 ms subinterval of a 12.5 ms PAwR subframe, the second time offset may be a multiple n=2 of a 1.25 ms subinterval of the 12.5 ms PAwR subframe, and so on. The wireless communication device (e.g., an AoA Rx ESL) may receive a PACTE from a third wireless communication device (e.g., a second AoA Tx ESL) among the plurality of wireless communication devices at a second synchronization time based on the reference time and the second time offset. The second synchronization time may be immediately after the first synchronization time associated with the AoA Rx ESL that received the PACTE from the second wireless communication device (e.g., the first AoA Tx ESL).

[0196] A network entity, network device, and / or wireless communication device may include various components, such as one or more input devices, one or more output devices, one or more processors, one or more microprocessors, one or more microcomputers, one or more cameras, one or more sensors, one or more receivers, transmitters, and / or transceivers, and / or other components configured to perform the process steps described herein. In some examples, a computing device may include a display, a network interface configured to transmit and / or receive data, any combination thereof, and / or other components. The network interface may be configured to transmit and / or receive data based on the Internet Protocol (IP) or other types of data.

[0197] can be implemented in a circuit configured to perform Figure 11 The process 1100 of an apparatus and / or device configured to perform Figure 12Components of the apparatus of process 1200. For example, the components may include and / or be implemented using electronic circuitry or other electronic hardware, which may include one or more programmable electronic circuits (e.g., a microprocessor, a graphics processing unit (GPU), a digital signal processor (DSP), a central processing unit (CPU), and / or other suitable electronic circuitry), and / or may include and / or be implemented using computer software, firmware, or any combination thereof, to perform the various operations described herein.

[0198] Process 1100 and process 1200 are illustrated as logical flow diagrams, the operations of which represent a sequence of operations that can be implemented in hardware, computer instructions, or a combination thereof. In the context of computer instructions, an operation represents a computer-executable instruction stored on one or more computer-readable storage media that, when executed by one or more processors, performs the operation. Generally, computer-executable instructions include routines, programs, objects, components, data structures, etc. that perform a specific function or implement a specific data type. The order in which the operations are described is not intended to be construed as limiting, and any number of the described operations can be combined in any order and / or in parallel to implement these processes.

[0199] In addition, process 1100, process 1200, and / or other processes described herein may be performed under the control of one or more computer systems configured with executable instructions and may be implemented through hardware or a combination thereof as code (e.g., executable instructions, one or more computer programs, or one or more applications) that is executed collectively on one or more processors. As described above, the code may be stored on a computer-readable or machine-readable storage medium, for example, in the form of a computer program including multiple instructions that can be executed by one or more processors. The computer-readable or machine-readable storage medium may be non-transitory.

[0200] Figure 13 is a block diagram illustrating an example of a computing system 1300 that may be employed by the disclosed systems and techniques. Specifically, Figure 13 An example of a computing system 1300 is shown, which can be, for example, any computing device comprising an internal computing system, a remote computing system, a camera, or any component in which components of the system communicate with each other using connection 1305. Connection 1305 can be a physical connection using a bus, or directly connected to processor 1310, such as in a chipset architecture. Connection 1305 can also be a virtual connection, a network connection, or a logical connection.

[0201] In some aspects, computing system 1300 is a distributed system, wherein the functionality described herein can be distributed across a data center, multiple data centers, a peer-to-peer network, etc. In some aspects, one or more of the described system components represent a plurality of such components, each performing some or all of the functionality of the described component. In some aspects, a component can be a physical or virtual device.

[0202] Example system 1300 includes at least one processing unit (CPU or processor) 1310 and connections 1305 that communicatively connect various system components, including system memory 1315, such as read-only memory (ROM) 1320 and random access memory (RAM) 1325, to processor 1310. Computing system 1300 may include a cache 1312 of high-speed memory directly connected to, proximate to, or integrated as part of processor 1310.

[0203] Processor 1310 may include any general-purpose processor and hardware or software services, such as services 1332, 1334, and 1336 stored in storage device 1330, configured to control processor 1310, as well as specialized processors, where the software instructions are incorporated into the actual processor design. Processor 1310 may essentially be a completely independent computing system, containing multiple cores or processors, buses, memory controllers, caches, etc. Multi-core processors may be symmetric or asymmetric.

[0204] To enable user interaction, computing system 1300 includes input device 1345, which can represent any number of input mechanisms, such as a microphone for voice, a touch-sensitive screen for gesture or graphical input, a keyboard, a mouse, motion input, voice, etc. Computing system 1300 can also include output device 1335, which can be one or more of a variety of output mechanisms. In some cases, a multimodal system can enable a user to provide multiple types of input / output to communicate with computing system 1300.

[0205] The computing system 1300 may include a communication interface 1340, which may generally control and manage user input and system output. The communication interface may use a wired and / or wireless transceiver to perform or facilitate the reception and / or transmission of wired and / or wireless communications, including utilizing an audio jack / plug, a microphone jack / plug, a Universal Serial Bus (USB) port / plug, an Apple TM Lightning TM Ports / plugs, Ethernet ports / plugs, fiber optic ports / plugs, proprietary wired ports / plugs, 3G, 4G, 5G and / or other cellular data network wireless signal transmission, Bluetooth TMWireless signal transmission, Bluetooth TM Low energy (BLE) wireless signal transmission, IBEACON TM Wireless signal transmission, radio frequency identification (RFID) wireless signal transmission, near field communication (NFC) wireless signal transmission, dedicated short range communication (DSRC) wireless signal transmission, 802.11 Wi-Fi wireless signal transmission, wireless local area network (WLAN) signal transmission, visible light communication (VLC), Worldwide Interoperability for Microwave Access (WiMAX), infrared (IR) communication wireless signal transmission, public switched telephone network (PSTN) signal transmission, integrated services digital network (ISDN) signal transmission, ad hoc network signal transmission, radio wave signal transmission, microwave signal transmission, infrared signal transmission, visible light signal transmission, ultraviolet light signal transmission, wireless signal transmission along the electromagnetic spectrum, or some combination thereof.

[0206] Communication interface 1340 may also include one or more range sensors (e.g., LIDAR sensors, laser rangefinders, RF radars, ultrasonic sensors, and infrared (IR) sensors) configured to collect data and provide measurements to processor 1310, so that processor 1310 can be configured to perform the determinations and calculations required to obtain the various measurements from the one or more range sensors. In some examples, the measurements may include time of flight, wavelength, azimuth, elevation, distance, linear velocity, and / or angular velocity, or any combination thereof. Communication interface 1340 may also include one or more Global Navigation Satellite System (GNSS) receivers or transceivers for determining the location of computing system 1300 based on one or more signals received from one or more satellites associated with one or more GNSS systems. GNSS systems include, but are not limited to, the US-based GPS, the Russian-based Global Navigation Satellite System (GLONASS), the Chinese-based BeiDou Navigation Satellite System (BDS), and the European-based Galileo GNSS. There is no limitation to operation on any particular hardware configuration, and thus the basic features herein may be readily replaced with improved hardware or firmware configurations as they are developed.

[0207] The storage device 1330 may be a non-volatile and / or non-transitory and / or computer-readable storage device and may be a hard disk or other type of computer-readable medium that can store computer-accessible data, such as a magnetic cassette, a flash memory card, a solid-state memory device, a digital versatile disk, a magnetic cassette, a floppy disk, a floppy disk, a hard disk, a magnetic tape, a magnetic stripe / strip, any other magnetic storage medium, a flash memory, a memristor memory, any other solid-state memory, a compact disc-read only memory (CD-ROM) disc, a rewritable compact disc (CD) disc, a digital video disc (DVD) disc, a Blu-ray disc (BDD) disc, a holographic disc, another optical medium, a secure digital (SD) card, a micro secure digital (microSD) card, a memory Stick® card, smart card chip, EMV chip, subscriber identity module (SIM) card, mini / micro / nano / pico SIM card, another integrated circuit (IC) chip / card, random access memory (RAM), static RAM (SRAM), dynamic RAM (DRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read-only memory (EPROM), electrically erasable programmable read-only memory (EEPROM), flash EPROM (FLASHEPROM), cache memory (e.g., first level (L1) cache, second level (L2) cache, third level (L3) cache, fourth level (L4) cache, fifth level (L5) cache, or other (L#) cache), resistive random access memory (RRAM / ReRAM), phase change memory (PCM), spin transfer torque RAM (STT-RAM), another memory chip or cartridge, and / or a combination thereof.

[0208] Storage devices 1330 may include software services, servers, and services. When the code defining such software is executed by processor 1310, it enables the system to perform a function. In some aspects, hardware services that perform a particular function may include software components stored on a computer-readable medium and the necessary hardware components, such as processor 1310, connection 1305, output device 1335, and the like, to perform that function. The term "computer-readable medium" includes, but is not limited to, portable or non-portable storage devices, optical storage devices, and various other media capable of storing, containing, or carrying instructions and / or data. Computer-readable media may include non-transitory media in which data may be stored and does not include carrier waves and / or transient electronic signals propagated over wireless or wired connections. Examples of non-transitory media may include, but are not limited to, magnetic disks or tapes, optical storage media such as compact disks (CDs) or digital versatile disks (DVDs), flash memory, memory, or storage devices. Computer-readable media may store thereon code and / or machine-executable instructions, which may represent a procedure, function, subroutine, program, routine, subroutine, module, software package, class, or any combination of instructions, data structures, or program statements. A code segment can be coupled to another code segment or a hardware circuit by passing and / or receiving information, data, arguments, parameters, or memory contents. Information, arguments, parameters, data, etc. can be passed, forwarded, or sent via any suitable means including memory sharing, message passing, token passing, network transmission, etc.

[0209] Specific details are provided in the above description to provide a comprehensive understanding of the aspects and examples provided herein, but those skilled in the art will appreciate that the present application is not limited thereto. Therefore, although the illustrative aspects of the present application have been described in detail herein, it should be understood that the present invention can be implemented and used in different ways, and the appended claims are intended to be interpreted as including these changes, except as limited by the prior art. The various features and aspects of the above application can be used alone or in combination. In addition, without departing from the broader scope of this specification, the various aspects can be used in any number of environments and applications outside the environment and application described herein. Therefore, the description and drawings should be regarded as illustrative rather than restrictive. For illustrative purposes, the method is described in a specific order. It should be understood that, in alternative aspects, these methods can be performed in a different order than described.

[0210] For explanation clarity, in some cases, the present technology can be presented as including a single functional block, which includes a device, a device component, a step or routine in a method implemented in software, or a combination of hardware and software. Additional components other than those shown in the figures and / or described herein can be used. For example, circuits, systems, networks, processes, and other components can be shown as components in block diagram form so as not to obscure these aspects in unnecessary details. In other cases, to avoid obscuring these aspects, known circuits, processes, algorithms, structures, and techniques can be shown without unnecessary details.

[0211] In addition, it will be understood by those skilled in the art that the various illustrative logic blocks, modules, circuits, and algorithmic steps described in conjunction with the aspects disclosed herein can be implemented as electronic hardware, computer software, or a combination of the two. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been generally described above in terms of their functions. Whether such functions are implemented as hardware or software depends on the specific application and the design constraints on the entire system. A skilled person can implement the described functions in different ways for each specific application, but such implementation decisions should not be interpreted as resulting in a departure from the scope of this disclosure.

[0212] The above aspects can be described as a process or method shown in a flow chart, flow diagram, data flow diagram, structure diagram or block diagram. Although a flow chart can describe the operations as a sequential process, many operations can be performed in parallel or simultaneously. In addition, the order of the operations can be rearranged. When the operations of the process are completed, the process is terminated, but may have additional steps not included in the figure. A process can correspond to a method, function, procedure, subroutine, subprogram, etc. When a process corresponds to a function, its termination can correspond to the function returning to the calling function or main function.

[0213] The processes and methods according to the examples described above can be implemented using computer-executable instructions stored in or otherwise obtained from a computer-readable medium. Such instructions may include, for example, instructions and data that cause or otherwise configure a general-purpose computer, a special-purpose computer, or a processing device to perform a specific function or group of functions. Some of the computer resources used may be accessed via a network. Computer-executable instructions may be, for example, binary, intermediate format instructions such as assembly language, firmware, source code. Examples of computer-readable media that can be used to store instructions, information, and / or information created during the methods according to the examples described include magnetic or optical disks, flash memory, USB devices equipped with non-volatile memory, network storage devices, and the like.

[0214] In some aspects, computer-readable storage devices, media, and memories may include wired or wireless signals including bit streams, etc. However, when referred to, non-transitory computer-readable storage media expressly excludes media such as energy, carrier signals, electromagnetic waves, and signals themselves.

[0215] Those skilled in the art will appreciate that a variety of different technologies and techniques may be used to represent information and signals. For example, in some cases, depending in part on the specific application, in part on the desired design, in part on the corresponding technology, etc., data, instructions, commands, information, signals, bits, symbols, and chips that may be mentioned throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0216] The various illustrative logical blocks, modules, and circuits described in conjunction with the aspects disclosed herein may be implemented or executed using hardware, software, firmware, middleware, microcode, hardware description languages, or any combination thereof, and may take on any of a variety of form factors. When implemented in software, firmware, middleware, or microcode, program code or code segments (e.g., a computer program product) that perform the necessary tasks may be stored on a computer-readable or machine-readable medium. A processor may perform the necessary tasks. Examples of form factors include laptops, smartphones, mobile phones, tablet devices or other small form factor personal computers, personal digital assistants, rack-mount devices, standalone devices, and the like. The functionality described herein may also be implemented in peripheral devices or add-in cards. As a further example, such functionality may also be implemented on different chips or processes executed on a circuit board within a single device.

[0217] Instructions, media for transmitting such instructions, computing resources for executing them, and other structure for supporting such computing resources are example components for providing the functionality described in this disclosure.

[0218] The techniques described herein may also be implemented in electronic hardware, computer software, firmware, or any combination thereof. Such techniques may be implemented in any of a variety of devices, such as a general-purpose computer, a wireless communication device handset, or a multi-purpose integrated circuit device with applications in wireless communication devices handsets and other devices. Any features described as modules or components may be implemented together in an integrated logic device or separately as discrete but interoperable logic devices. If implemented in software, the techniques may be implemented at least in part by a computer-readable data storage medium containing program code, including instructions that, when executed, perform one or more of the methods, algorithms, and / or operations described above. The computer-readable data storage medium may form part of a computer program product, which may include packaging materials. The computer-readable medium may include memory or data storage media, such as random access memory (RAM) such as synchronous dynamic random access memory (SDRAM), read-only memory (ROM), non-volatile random access memory (NVRAM), electrically erasable programmable read-only memory (EEPROM), flash memory, magnetic or optical data storage media, and the like. Additionally or alternatively, these techniques may be implemented at least in part by a computer-readable communication medium that carries or communicates program code in the form of instructions or data structures and that can be accessed, read, and / or executed by a computer, such as a propagated signal or wave.

[0219] The program code may be executed by a processor, which may include one or more processors, such as one or more digital signal processors (DSPs), general-purpose microprocessors, application-specific integrated circuits (ASICs), field-programmable logic arrays (FPGAs), or other equivalent integrated or discrete logic circuitry. Such a processor may be configured to perform any of the techniques described in this disclosure. A general-purpose processor may be a microprocessor; however, the processor may alternatively be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, such as a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in combination with a DSP core, or any other such configuration. Therefore, the term "processor," as used herein, may refer to any of the foregoing structures, any combination of the foregoing structures, or any other structure or apparatus suitable for implementing the techniques described herein.

[0220] One of ordinary skill will understand that the less than ("<") and greater than (">") symbols or terms used herein may be replaced by the less than or equal to ("≤") and greater than or equal to ("≥") symbols, respectively, without departing from the scope of the present specification.

[0221] When a component is described as being “configured to” perform a particular operation, such configuration can be achieved by designing electronic circuits or other hardware to perform the operation, by programming a programmable electronic circuit (e.g., a microprocessor or other suitable electronic circuit) to perform the operation, or any combination thereof.

[0222] The phrases “coupled to” or “communicatively coupled to” refer to any component that is physically connected directly or indirectly to another component, and / or any component that communicates directly or indirectly with another component (e.g., via a wired or wireless connection and / or other suitable communication interface).

[0223] Claim language or other language reciting "at least one of" a set and / or "one or more" a set indicates that one member of the set or multiple members of the set (in any combination) satisfies the claim. For example, claim language reciting "at least one of A and B" or "at least one of A or B" means A, B, or A and B. In another example, claim language reciting "at least one of A, B, and C" or "at least one of A, B, or C" means A, B, C, or A and B, or A and C, or B and C, or A, B, and C. The language "at least one of" a set and / or "one or more" a set does not limit the set to the items listed in the set. For example, claim language reciting "at least one of A and B" or "at least one of A or B" can mean A, B, or A and B, and can additionally include items not listed in the set of A and B.

[0224] Illustrative aspects of the invention include:

[0225] Aspect 1. A wireless communication device for wireless communication, the wireless communication device comprising: at least one memory; and at least one processor, coupled to the at least one memory and configured to: receive synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; determine a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of multiple wireless communication devices including the wireless communication device; and send a second set of PAs at a synchronization time based on the reference time and the first time offset, each PA in the second set of PAs comprising a constant tone extension (CTE).

[0226] Aspect 2. The wireless communication device according to aspect 1, wherein the at least one processor is configured to determine the synchronization time as a sum of a reference time and a multiple of a predetermined time offset interval.

[0227] Aspect 3. The wireless communication device of aspect 2, wherein: information associated with a predetermined time offset interval is received from a network entity; and a length of the predetermined time offset interval is the same as a length of a sub-portion of a periodic advertisement with a response (PAwR) subframe.

[0228] Aspect 4. The wireless communication device of any one of aspects 1 to 3, wherein: the first set of PAs comprises a periodic advertisement with response (PAwR) sequence associated with a network entity; and the second set of PAs comprises a PA with a CTE sequence associated with the wireless communication device.

[0229] Aspect 5. The wireless communication device according to any one of aspects 1 to 4, wherein the synchronization information is included in an access point synchronization (AP_SYNC) packet.

[0230] Aspect 6. The wireless communication device of aspect 5, wherein the reference time is a time associated with transmission of an AP_SYNC packet.

[0231] Aspect 7. A wireless communication device according to any one of aspects 3 to 6, wherein: the subframe includes multiple non-overlapping time slots, the multiple non-overlapping time slots including a subset of reserved time slots for PAwR responses and a subset of non-reserved time slots; and each PA in the second set of PAs uses a specific time slot in the subset of non-reserved time slots to transmit.

[0232] Aspect 8. The wireless communication device of aspect 7, wherein the subset of reserved time slots includes a plurality of access point synchronization (AP_SYNC) response time slots, the plurality of AP_SYNC response time slots and the reserved time slots being associated with different time durations.

[0233] Aspect 9. The wireless communication device of aspect 8, wherein the plurality of AP_SYNC response slots comprises at least three AP_SYNC response slots.

[0234] Aspect 10. A wireless communication device according to any one of Aspects 1 to 9, wherein at least one processor is configured to: determine one or more parameters associated with forming a PA sequence, the one or more parameters being based on a time slot index included in synchronization information; send the one or more parameters to a network entity; form a PA sequence using the one or more parameters; and send a second set of PAs using the PA sequence.

[0235] Aspect 11. A wireless communication device according to aspect 10, wherein: the first time slot of the PA sequence is associated with a second set of PAs including CTE; and the second time slot of the PA sequence is associated with an additional set of PAs, each PA in the additional set of PAs including CTE and transmitted on the PA sequence by the second wireless communication device.

[0236] Aspect 12. The wireless communication device according to any one of aspects 10 to 11, wherein the at least one processor is configured to determine one or more parameters associated with forming the PA sequence based on synchronization information comprising invalid values for one or more predetermined fields.

[0237] Aspect 13. The wireless communication device of aspect 12, wherein the one or more predetermined fields include one or more of a group ID field, an access address field, or an event counter field.

[0238] Aspect 14. The wireless communication device according to any one of aspects 1 to 13, wherein the network entity is an access point (AP).

[0239] Aspect 15. The wireless communication device according to any one of aspects 1 to 14, wherein the wireless communication device is an electronic shelf label (ESL).

[0240] Aspect 16. A wireless communication device for wireless communication, the wireless communication device comprising: at least one memory; and at least one processor, coupled to the at least one memory and configured to: receive synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; determine a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of multiple wireless communication devices including the wireless communication device; and receive a second set of PAs from a second wireless communication device among the multiple wireless communication devices at a synchronization time based on the first time offset and the reference time, each PA in the second set of PAs comprising a constant tone extension (CTE).

[0241] Aspect 17. The wireless communication device of aspect 16, wherein the at least one processor is configured to determine the synchronization time as a sum of the reference time and a first multiple of the predetermined time offset interval.

[0242] Aspect 18. The wireless communication device of aspect 17, wherein: information associated with a predetermined time offset interval is received from a network entity; and a length of the predetermined time offset interval is the same as a length of a sub-portion of a periodic advertisement with a response (PAwR) subframe.

[0243] Aspect 19. A wireless communication device according to any one of Aspects 17 to 18, wherein at least one processor is further configured to: determine a second time offset from a reference time based on synchronization information, the second time offset including a second multiple of a predetermined time offset interval that is different from the first multiple; and receive a PA including a CTE from a third wireless communication device among a plurality of wireless communication devices at a second synchronization time based on the reference time and the second time offset.

[0244] Aspect 20. The wireless communication device of any one of aspects 16 to 19, wherein: the first set of PAs comprises a periodic advertisement with response (PAwR) sequence associated with a network entity; and the second set of PAs comprises a PA with a CTE sequence associated with a second wireless communication device.

[0245] Aspect 21. The wireless communication device according to any one of aspects 16 to 20, wherein the synchronization information is synchronization information generated by the second wireless communication device and is associated with sending one or more PACTEs received by the wireless communication device.

[0246] Aspect 22. The wireless communication device of any one of aspects 16 to 21, wherein the synchronization information is included in an access point synchronization (AP_SYNC) packet.

[0247] Aspect 23. The wireless communication device of aspect 22, wherein the reference time is a time associated with transmission or reception of an AP_SYNC packet.

[0248] Aspect 24. The wireless communication device according to any one of aspects 21 to 23, wherein the synchronization information comprises one or more of a slot index, a group ID field, an access address field, or an event counter field associated with the wireless communication device.

[0249] Aspect 25. A wireless communication device according to any one of aspects 18 to 24, wherein: the subframe includes a plurality of non-overlapping time slots, the plurality of non-overlapping time slots including a subset of reserved time slots for PAwR responses and a subset of non-reserved time slots; and each PA in the second set of PAs is received using a particular time slot in the subset of non-reserved time slots.

[0250] Aspect 26. The wireless communication device of aspect 25, wherein the subset of reserved time slots includes a plurality of access point synchronization (AP_SYNC) response time slots, the plurality of AP_SYNC response time slots and the reserved time slots being associated with different time durations.

[0251] Aspect 27. The wireless communication device of aspect 26, wherein the plurality of AP_SYNC response slots comprises at least three AP_SYNC response slots.

[0252] Aspect 28. A wireless communication device according to any of Aspects 16 to 27, wherein the at least one processor is configured to: receive a second set of PAs from a second wireless communication device using a first time slot of a PA CTE sequence; and receive a third set of PAs from a third wireless communication device using a time slot of the PA CTE sequence that is different from the first time slot, wherein the second set of PAs and the third set of PAs each include one or more PA CTEs.

[0253] Aspect 29. The wireless communication device according to any one of aspects 16 to 28, wherein the network entity is an access point (AP).

[0254] Aspect 30. The wireless communication device according to any one of aspects 16 to 29, wherein the wireless communication device is an electronic shelf label (ESL).

[0255] Aspect 31. A wireless communication method performed at a wireless communication device, the method comprising: receiving synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; determining a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of multiple wireless communication devices including the wireless communication device; and sending a second set of PAs at a synchronization time based on the reference time and the first time offset, each PA in the second set of PAs comprising a constant tone extension (CTE).

[0256] Aspect 32. The method according to Aspect 31, further comprising: determining the synchronization time as a sum of a reference time and a multiple of a predetermined time offset interval.

[0257] Aspect 33. The method of aspect 32, wherein: information related to the predetermined time offset interval is received from the network entity; and a length of the predetermined time offset interval is the same as a length of a sub-portion of a periodic advertisement with response (PAwR) subframe.

[0258] Aspect 34. The method of any of Aspects 31 to 33, wherein: the first set of PAs comprises a periodic advertisement with response (PAwR) sequence associated with a network entity; and the second set of PAs comprises a PA with a CTE sequence associated with a wireless communication device.

[0259] Aspect 35. The method according to any one of aspects 31 to 34, wherein the synchronization information is included in an access point synchronization (AP_SYNC) packet.

[0260] Aspect 36. The method of aspect 35, wherein the reference time is a time associated with transmission of an AP_SYNC packet.

[0261] Aspect 37. A method according to any one of Aspects 33 to 36, wherein: the subframe includes multiple non-overlapping time slots, the multiple non-overlapping time slots including a subset of reserved time slots for PAwR responses and a subset of non-reserved time slots; and each PA in the second set of PAs uses a specific time slot in the subset of non-reserved time slots to transmit.

[0262] Aspect 38. The method of aspect 37, wherein the subset of reserved time slots includes a plurality of access point synchronization (AP_SYNC) response time slots, the plurality of AP_SYNC response time slots and the reserved time slots being associated with different time durations.

[0263] Aspect 39. The method of aspect 38, wherein the plurality of AP_SYNC response slots comprises at least three AP_SYNC response slots.

[0264] Aspect 40. The method according to any one of Aspects 31 to 39 further includes: determining one or more parameters associated with forming a PA sequence, the one or more parameters being based on a time slot index included in the synchronization information; sending the one or more parameters to a network entity; forming a PA sequence using the one or more parameters; and sending a second set of PAs using the PA sequence.

[0265] Aspect 41. The method of aspect 40, wherein: the first time slot of the PA sequence is associated with a second set of PAs including CTE; and the second time slot of the PA sequence is associated with an additional set of PAs, each PA in the additional set of PAs including CTE and transmitted on the PA sequence by the second wireless communication device.

[0266] Aspect 42. The method according to any one of aspects 40 to 41, further comprising determining one or more parameters associated with forming the PA sequence based on synchronization information comprising invalid values for one or more predetermined fields.

[0267] Aspect 43. The method according to aspect 42, wherein the one or more predetermined fields include one or more of a group ID field, an access address field, or an event counter field.

[0268] Aspect 44. The method according to any one of aspects 31 to 43, wherein the network entity is an access point (AP).

[0269] Aspect 45. The method according to any one of aspects 31 to 44, wherein the wireless communication device is an electronic shelf label (ESL).

[0270] Aspect 46. A wireless communication method performed at a wireless communication device, the method comprising: receiving synchronization information associated with a first set of periodic advertisements (PAs) (PAs) from a network entity; determining a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of multiple wireless communication devices including the wireless communication device; and receiving a second set of PAs from a second wireless communication device among the multiple wireless communication devices at a synchronization time based on the first time offset and the reference time, each PA in the second set of PAs comprising a constant tone extension (CTE).

[0271] Aspect 47. The method according to Aspect 46, further comprising determining the synchronization time as a sum of the reference time and a first multiple of the predetermined time offset interval.

[0272] Aspect 48. The method of aspect 47, wherein: information related to the predetermined time offset interval is received from the network entity; and a length of the predetermined time offset interval is the same as a length of a sub-portion of a periodic advertisement with response (PAwR) subframe.

[0273] Aspect 49. The method according to any one of Aspects 47 to 48 further includes: determining a second time offset from a reference time based on synchronization information, the second time offset including a second multiple of a predetermined time offset interval that is different from the first multiple; and receiving a PA including a CTE from a third wireless communication device among a plurality of wireless communication devices at a second synchronization time based on the reference time and the second time offset.

[0274] Aspect 50. The method of any one of aspects 46 to 49, wherein: the first set of PAs comprises a periodic advertisement with response (PAwR) sequence associated with a network entity; and the second set of PAs comprises a PA with a CTE sequence associated with a second wireless communication device.

[0275] Aspect 51. The method according to any one of aspects 46 to 50, wherein the synchronization information is synchronization information generated by the second wireless communication device and is associated with sending one or more PACTEs received by the wireless communication device.

[0276] Aspect 52. The method according to any one of aspects 46 to 51, wherein the synchronization information is included in an access point synchronization (AP_SYNC) packet.

[0277] Aspect 53. The method of aspect 52, wherein the reference time is a time associated with the transmission or reception of an AP_SYNC packet.

[0278] Aspect 54. The method according to any one of aspects 51 to 53, wherein the synchronization information comprises one or more of a time slot index, a group ID field, an access address field, or an event counter field associated with the wireless communication device.

[0279] Aspect 55. A method according to any one of Aspects 48 to 54, wherein: the subframe includes a plurality of non-overlapping time slots, the plurality of non-overlapping time slots including a subset of reserved time slots for PAwR responses and a subset of non-reserved time slots; and each PA in the second set of PAs is received using a particular time slot in the subset of non-reserved time slots.

[0280] Aspect 56. The method of aspect 55, wherein the subset of reserved time slots includes a plurality of access point synchronization (AP_SYNC) response time slots, the plurality of AP_SYNC response time slots and the reserved time slots being associated with different time durations.

[0281] Aspect 57. The method of aspect 56, wherein the plurality of AP_SYNC response slots comprises at least three AP_SYNC response slots.

[0282] Aspect 58. The method according to any one of aspects 46 to 57 further includes: receiving a second set of PAs from a second wireless communication device using a first time slot of a PA CTE sequence; and receiving a third set of PAs from a third wireless communication device using a time slot of a PA CTE sequence different from the first time slot, wherein the second set of PAs and the third set of PAs each include one or more PA CTEs.

[0283] Aspect 59. The method according to any one of aspects 46 to 58, wherein the network entity is an access point (AP).

[0284] Aspect 60. The method according to any one of aspects 46 to 59, wherein the wireless communication device is an electronic shelf label (ESL).

[0285] Aspect 61. A non-transitory computer-readable medium comprising instructions that, when executed by at least one processor, cause the at least one processor to perform operations according to any one of aspects 31 to 45.

[0286] Aspect 62. An apparatus for wireless communication, the apparatus comprising one or more means for performing the operations according to any one of Aspects 31 to 45.

[0287] Aspect 63. A non-transitory computer-readable medium comprising instructions that, when executed by at least one processor, cause the at least one processor to perform operations according to any one of aspects 46 to 60.

[0288] Aspect 64. An apparatus for wireless communications, the apparatus comprising one or more means for performing the operations according to any one of aspects 46 to 60.

Claims

1. A wireless communication device for wireless communication, the wireless communication device comprising: at least one memory; as well as at least one processor coupled to the at least one memory and configured to: receiving synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; determining a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of a plurality of wireless communication devices including the wireless communication device; as well as A second set of PAs is transmitted at synchronized times based on the reference time and the first time offset, each PA in the second set of PAs comprising a constant tone extension (CTE).

2. The wireless communication device according to claim 1, wherein The at least one processor is configured to: The synchronization time is determined as a sum of the reference time and a multiple of a predetermined time offset interval.

3. The wireless communication device according to claim 2, wherein: receiving information associated with the predetermined time offset interval from the network entity; and The predetermined time offset interval has a length that is the same as a length of a sub-portion of a periodic advertisement with response (PAwR) sub-frame.

4. The wireless communication device of claim 1 , wherein: said first set of PAs comprising a sequence of periodic advertisements with responses (PAwR) associated with said network entity; and The second set of PAs includes PAs having CTE sequences associated with the wireless communication device.

5. The wireless communication device according to claim 1, wherein The synchronization information is included in an access point synchronization (AP_SYNC) packet. The wireless communication device according to claim 5 , wherein: The reference time is a time associated with the transmission of the AP_SYNC packet.

7. The wireless communication device of claim 3, wherein: The subframe includes a plurality of non-overlapping time slots, the plurality of non-overlapping time slots including a subset of reserved time slots for PAwR responses and a subset of non-reserved time slots; and Each PA in the second set of PAs transmits using a particular time slot in the subset of non-reserved time slots.

8. The wireless communication device according to claim 7, wherein: The subset of reserved time slots includes a plurality of access point synchronization (AP_SYNC) response time slots, the plurality of AP_SYNC response time slots and the reserved time slots being associated with different time durations.

9. The wireless communication device according to claim 8, wherein: The plurality of AP_SYNC response time slots include at least three AP_SYNC response time slots.

10. The wireless communication device according to claim 1, wherein The at least one processor is configured to: determining one or more parameters associated with forming a PA sequence, the one or more parameters being based on a slot index included in the synchronization information; sending the one or more parameters to the network entity; forming the PA sequence using the one or more parameters; and The second set of PAs is sent using the PA sequence.

11. The wireless communication device of claim 10, wherein: a first time slot of the PA sequence is associated with the second set of PAs including the CTE; and A second time slot of the PA sequence is associated with an additional set of PAs, each PA in the additional set of PAs includes the CTE and is transmitted on the PA sequence by a second wireless communication device.

12. The wireless communication device according to claim 10, wherein: The at least one processor is configured to determine the one or more parameters associated with forming the PA sequence based on the synchronization information including invalid values for one or more predetermined fields.

13. The wireless communication device according to claim 12, wherein: The one or more predetermined fields include one or more of a group ID field, an access address field, or an event counter field.

14. The wireless communication device according to claim 1, wherein The network entity is an access point (AP).

15. The wireless communication device according to claim 1, wherein The wireless communication device is an electronic shelf label (ESL).

16. A wireless communication device for wireless communication, the wireless communication device comprising: at least one memory; as well as at least one processor coupled to the at least one memory and configured to: receiving synchronization information associated with a first set of periodic advertisements (PAs) from a network entity; determining a first time offset from a reference time based on the synchronization information, wherein the reference time is associated with synchronization of a plurality of wireless communication devices including the wireless communication device; as well as A second set of PAs is received from a second wireless communication device of the plurality of wireless communication devices at a synchronization time based on the first time offset and the reference time, each PA of the second set of PAs including a constant tone extension (CTE).

17. The wireless communication device according to claim 16, wherein: The at least one processor is configured to: The synchronization time is determined as a sum of the reference time and a first multiple of a predetermined time offset interval.

18. The wireless communication device of claim 17, wherein: receiving information associated with the predetermined time offset interval from the network entity; and The predetermined time offset interval has a length that is the same as a length of a sub-portion of a periodic advertisement with response (PAwR) sub-frame.

19. The wireless communication device according to claim 17, wherein: The at least one processor is further configured to: determining, based on the synchronization information, a second time offset from the reference time, the second time offset comprising a second multiple of the predetermined time offset interval that is different from the first multiple; as well as A PA including a CTE is received from a third wireless communication device among the plurality of wireless communication devices at a second synchronization time based on the reference time and the second time offset.

20. The wireless communication device of claim 16, wherein: said first set of PAs comprising a sequence of periodic advertisements with responses (PAwR) associated with said network entity; and The second set of PAs includes PAs having CTE sequences associated with the second wireless communication device.

21. The wireless communication device of claim 16, wherein: The synchronization information is synchronization information generated by the second wireless communication device and is associated with sending one or more PACTEs received by the wireless communication device.

22. The wireless communication device of claim 16, wherein: The synchronization information is included in an access point synchronization (AP_SYNC) packet.

23. The wireless communication device according to claim 22, wherein: The reference time is a time associated with the transmission or reception of the AP_SYNC packet.

24. The wireless communication device of claim 21, wherein: The synchronization information includes one or more of a time slot index, a group ID field, an access address field, or an event counter field associated with the wireless communication device.

25. The wireless communication device of claim 18, wherein: The subframe includes a plurality of non-overlapping time slots, the plurality of non-overlapping time slots including a subset of reserved time slots for PAwR responses and a subset of non-reserved time slots; and Each PA in the second set of PAs receives using a particular time slot in the subset of non-reserved time slots.

26. The wireless communication device of claim 25, wherein: The subset of reserved time slots includes a plurality of access point synchronization (AP_SYNC) response time slots, the plurality of AP_SYNC response time slots and the reserved time slots being associated with different time durations.

27. The wireless communication device of claim 26, wherein: The plurality of AP_SYNC response time slots include at least three AP_SYNC response time slots.

28. The wireless communication device of claim 16, wherein: The at least one processor is configured to: receiving the second set of PAs from the second wireless communication device using a first time slot of a PA CTE sequence; and A third set of PAs is received from a third wireless communication device using a time slot having a different PA CTE sequence than the first time slot, wherein the second set of PAs and the third set of PAs each include one or more PA CTEs.

29. The wireless communication device of claim 16, wherein: The network entity is an access point (AP).

30. The wireless communication device of claim 16, wherein: The wireless communication device is an electronic shelf label (ESL).

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