A scheduling offset between an uplink and downlink radio frame timing structure of a user equipment (UE) may be updated to provide for more efficient utilization of hybrid automatic repeat request (HARQ) processes in a non-terrestrial network. For instance, different UEs may experience different round trip delays (RTDs) with a non-terrestrial cell. Different UEs may be configured with different scheduling offsets such that scheduling delays may be reduced and HARQ processes identifiers may be reused more rapidly. Additionally or alternatively, wireless communications systems may define one or more separation distances (or timing thresholds) for timing between communications and HARQ processes may be reused based on the separation distance threshold (e.g., such that a satellite may reuse a HARQ process ID for two scheduled communications that have not yet been performed by the UE).

The present disclosure provides a method for transmitting and receiving a synchronization signal block in a 5G system, and a device for transmitting and receiving a synchronization signal block in a 5G system. The method includes: determining a time-domain position of a synchronization subframe, the synchronization subframe being configured to transmit the synchronization signal block, and the synchronization signal block at least comprising a signal for measurement; and transmitting the synchronization signal block according to the position of the synchronization subframe within 5 milliseconds; wherein determining a time-domain position of a synchronization subframe includes: determining a first subframe as the synchronization subframe within 5 milliseconds; or determining first two subframes within 5 milliseconds in a radio frame as the synchronization subframe, wherein the first two subframes comprise a first subframe and a second subframe.

This technology allows time synchronization in wireless networks with mobile stations. A wireless network controller transmits instructions to access points (“APs”) within the wireless network to monitor transmissions for time synchronization. One or more second APs observe fine time measurement (“FTM”) exchanges between a first AP and a mobile station. A particular second AP determines whether to perform a time synchronization with the first AP based on the detection of the FTM exchange or a determination that the station is moving toward the second AP. For time synchronization, the second AP determines the time that the first AP transmitted the FTM exchange and the time of transmission from the first AP to the second AP. The second AP synchronizes a second AP clock to the summation of the time of the transmission of the FTM exchange and the time of transmission from the first AP to the second AP.

A first UL or SL signal received by one UE from another UE is utilized to determine: a time of arrival for the first UL or SL signal relative to a reference time for the first UL or SL signal; a propagation time for the first UL or SL signal; a distance between the UE and the other UE determined based on at least the time of arrival for the first UL or SL signal, a first round trip time for transmissions between a base station and the other UE, and a second round trip time for transmissions between the base station and the UE; and an angle of arrival relative to a coordinate system of the UE for one of a second UL signal or a second SL signal from the other UE.

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a first wireless node may receive, from a second wireless node, a round-trip time timing advance indicator, wherein the round-trip time timing advance indicator is different from a timing advance indicator used for an uplink transmission timing advance message. In some aspects, the first wireless node may synchronize a timing configuration of the first wireless node to at least one of the second wireless node or a third wireless node based at least in part on the round-trip time timing advance indicator. Numerous other aspects are provided.

This application provides methods and apparatuses for uplink timing synchronization. The method includes: determining, based on beam information of a first beam and ephemeris information of the satellite base station, an uplink timing frame number of a first cell corresponding to the first beam; determining timing information of a first terminal device in the first cell based on the uplink timing frame number of the first cell, where the timing information is used to indicate a timing advance or a timing lag; and outputting the timing information.

Disclosed are techniques for handling of radio frequency front-end group delays (GDs) for round trip time (RTT) estimation. In an aspect, a network entity determines information indicating a network total GD and a user equipment (UE) determines information indicating a UE total GD. The network entity transmits one or more RTT measurement (RTTM) signals to the UE, each including a RTTM waveform. The UE determines one or more one or more RTT response (RTTR) payloads for one or more RTTR signals, each including a RTTR waveform. The UE transmits the RTTR signal(s) to the network entity. For each RTTR signal, a transmission time of the RTTR waveform and/or the RTTR payload is/are determined based on the UE total GD. The network entity determines a RTT between the UE and the network entity based on the RTTM signal(s), the RTTR signal(s), and the information indicating the network total GD.

In an aspect, a communications node (e.g., TRP or UE) obtains (e.g., measures) timing group delays associated with different positioning procedures to determine time drift information, and reports the time drift information to an external entity for position estimation.

A method comprising: accessing a response mapping defining a set of safety-critical functions associated with a safety-critical latency threshold and a set of safety responses, each safety response corresponding to a safety-critical function; executing a time-synchronization protocol with a transmitting system to calculate a clock reference; accessing a safety message schedule indicating an expected arrival time for each safety message in a series of safety messages based on the clock reference; for each safety message in the series of safety messages, calculating a latency of the safety message based on an arrival time of the safety message and the expected arrival time; and in response to a latency of a current safety message in the series of safety messages exceeding the safety-critical latency threshold, initiating the safety response corresponding to the safety-critical function for each safety-critical function in the set of safety-critical functions.

The present disclosure relates to a pre-5.sup.th-Generation (5G) or 5G communication system to be provided for supporting higher data rates Beyond 4.sup.th-Generation (4G) communication system such as Long Term Evolution (LTE). The communication method of a base station in a wireless communication system, according to one embodiment of the disclosure, can comprise the steps of: setting a transmission period of a poll bit for indicating the transmission of information on whether a packet has been successfully received; generating a packet including the poll bit set on the basis of the transmission period; and transmitting the generated packet to a terminal.