A position estimation unit (2) comprising a first transceiver device (3) and a processing unit (10) that is arranged to repeatedly calculate time-of-flight (TOF) for radio signals (x.sub.1, x.sub.2, x.sub.3, x.sub.4, x.sub.5, x.sub.6) sent pair-wise between two transceivers among the first transceiver device (3) and at least two other transceiver devices (7, 8, 9); calculate possible positions for the transceiver devices (3, 7, 8, 9), which results in possible positions for each transceiver device (3, 7, 8, 9); and perform Multidimensional scaling (MDS) calculation in order to obtain relative positions of the transceiver devices (3, 7, 8, 9) in a present coordinate system. After two initial MDS calculations, between every two consecutive MDS calculations, the processing unit (10) is arranged to repeatedly perform a processing procedure comprising translation, scaling and rotation of present coordinate system such that a corrected present coordinate system is acquired. The processing procedure is arranged to determine the corrected present coordinate system such that a smallest change for the relative positions of the transceiver devices (3, 7, 8, 9) between the consecutive MDS calculations is obtained.

Provided is a system for time synchronization between a server and an Internet-of-Things (IoT) device. The system may include a server configured to broadcast a time-point synchronization signal including absolute time point information; and an IoT device configured to receive the broadcast time-point synchronization signal and calculate absolute time point information by using the absolute time point information included in the time-point synchronization signal, computation time information according to an internal computation operation, and transmission time information required to receive the time-point synchronization signal.

A range is determined between two unsynchronized communications terminals in which a first terminal transmits a range request to a second terminal. The first terminal stores a first timestamp in memory corresponding to a time at which the range request message was transmitted. A range response is later received by the first terminal from the second terminal. The range response includes a residence time that characterizes an amount of time the second terminal required to send the range response after receiving the range request. The first terminal later stores a second timestamp in memory corresponding to a time at which the range response was received. Based on the second timestamp minus the first timestamp and the residence time, a roundtrip time for the range request is calculated. This roundtrip time can be used to calculate a distance between the first terminal and the second terminal based on the roundtrip time.

In performing wireless communication between terminals to perform time difference measurement and propagation time measurement, first and second terminals that transmit a signal at least once in attempting space-time synchronization are included. The first terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the second terminal, adds a positive or negative phase to the measured reception phase, and makes a report to the second terminal. The second terminal measures a reception phase of a locally transmitted signal, and a reception phase of a signal transmitted by the first terminal, and makes a report to the first terminal. The first and second terminals obtain a time difference or propagation time according to a reception phase measured by a local device and reported from a counterpart, and obtain additional information based on a phase reflected in the time difference or propagation time.

In various embodiments, crowd sourcing techniques are provided to enable RTT-based positioning of UE. To address issues of discovering which beacons (e.g., Wi-Fi APs, cellular base stations, BLE transmitters, etc.) support measurement of RTT (e.g., according to IEEE 802.11mc, 3GPP Release 16, etc.), beacon RTT capabilities may be crowd-sourced from UE and maintained by a cloud-based location platform in a beacon database (or more specifically, a RTT database portion thereof). To address the issue of determining physical antenna positions, RTT measurements may be crowd-sourced from UE for those beacons that am RTT capable, and used by a trilateration algorithm (e.g., a WLS multilateration algorithm) to determine physical antenna positions, which also may be maintained in the beacon database. Accuracy of the trilateration may be enhanced by obtaining raw GNSS measurements (e.g., psuedoranges) from the UE, and performing a cloud-based RTK GNSS position fix for the UE.

Components, systems, and methods for determining propagation delay of communications in distributed antenna systems are disclosed. The propagation delay of communications signals distributed in the distributed antenna systems is determined. If desired, the propagation delay(s) can be determined on a per remote antenna unit basis for the distributed antenna systems. The propagation delay(s) can provided by the distributed antenna systems to a network or other system to be taken into consideration for communications services or operations that are based on communications signal delay. As another non-limiting example, propagation delay can be determined and controlled for each remote antenna unit to uniquely distinguish the remote antenna units. In this manner, the location of a client device communicating with a remote antenna unit can be determined within the communication range of the remote antenna unit.

In embodiments of distributed coordination of mesh network configuration updates, pending commissioning datasets are managed and distributed to coordinate configuration changes of parameters that control participation in, and secure communication over, a mesh network. Pending network commissioning datasets are managed across fragmentation of the mesh network into multiple partitions and subsequent merging of the fragments to ensure that the most recent updates to pending commissioning datasets are propagated to mesh network devices and that all mesh network devices will receive pending commissioning datasets before the time that the pending commissioning dataset becomes the active commissioning dataset for the mesh network.

A first communication device generates a range measurement packet (or a packet that includes a probe response frame, a TIM frame, etc.) associated with a range measurement signal exchange session between the first communication device and a second communication device. The first communication device records a time value of a first timer corresponding to a time of transmission of the packet, and includes timing information corresponding to the recorded time value in the packet. The first communication device transmits the packet to the second communication device. The timing information in the packet is useable by a third communication device to adjust time values corresponding to a second timer, which the third communication device includes.

Disclosed embodiments pertain to a first STA may broadcast a first Null Data Packet Announcement (NDPA) frame with an indication of one or more second STAs being polled. Subsequent to the first NDPA frame, a Null Data Packet (NDP) frame may be broadcast from a plurality of antennas on the first STA and one or more corresponding first Fine Timing Measurement (FTM) frames may be received in response. Each corresponding first FTM frame may be received from a distinct corresponding second STA and may comprise corresponding ranging measurements between the first STA and the corresponding second STA as determined by the corresponding second STA based on the NDP frame. In some embodiments, the one or more corresponding first FTM frames may be: received in response to a previously broadcast trigger frame, and encoded using Orthogonal Frequency Division Multiple Access. The trigger frame may be broadcast subsequent to the NDP frame.

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may identify a set of carriers configured for communications between the UE and one or more transmission reception points (e.g., a set of transmission points). The UE may receive multiple communications over different carriers and determine a time difference or delay between two of the carriers (e.g., a first carrier and a second carrier). Based on the time difference and a time difference threshold, the UE may perform a throughput degradation procedure such as transmitting a report indicating the time difference, transmitting a feedback report with channel quality information determined based on the time difference, etc.