Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may receive, from a serving node associated with a non-terrestrial network (NTN), one or more timing advance (TA) values. The UE may transmit, to the serving node of the NTN, uplink signaling based at least in part on a reference timing for the uplink signaling, wherein the reference timing for the uplink signaling is based at least in part on a reference timing of a downlink signaling and the one or more TA values, wherein the one or more TA values include a UE-specific TA value, and wherein a reference timing of the UE-specific TA value is for: a first propagation delay on a service link between the UE and a satellite associated with the NTN, and a second propagation delay on the service link. Numerous other aspects are described.

Systems and methods for facilitating handover reduction in satellite systems are disclosed. A system may include a processor and a memory storing instructions, which when executed by the processor, may cause the processor to detect a user terminal that is selected for a handover procedure. The handover procedure may facilitate a switch from a source beam to a target beam. Based on input data, the processor may evaluate an ideal time value pertaining to a pre-defined time instance at which a scheduled handover is to be performed. The scheduled handover may correspond to at least one of a scheduled change in operating frequency within same beam or a scheduled feeder link handover due to a change in gateway communicating with the satellite. Based on the evaluation and the input data, the processor may estimate an optimized time value that pertains to an optimized time instance associated with an expected handover reduction.

Embodiments relate to systems and methods for modifying the playback rate of media data in order to improve craft-based media playback system performance during handover events in a communication system.

A method for beam tracking and refinement in a 5G network includes determining, by a beam steering station, a first plurality of angular directions based on a first starting angular direction, a first ending angular direction and a first angular step; determining a first angular direction based on a first plurality of antenna gains associated with the first plurality of angular directions; determining a second plurality of angular directions based on a second starting angular direction, a second ending angular direction and a second angular step, wherein the first angular direction is in the middle of the second plurality of angular directions; determining a second angular direction based on a second plurality of antenna gains associated with the second plurality of angular directions; and in response to a change between the first and second angular direction being below a threshold, performing beam steering based on the second angular direction.

In a wireless communication system in which a relay device provided on a mobile object communicates wirelessly with a plurality of communication devices present in places different from each other, each of the communication devices includes a communication device transmission unit which transmits test signals at a plurality of timings during a time frame when communication with the relay device is possible, a communication device reception unit which receives, from the relay device, communication situation information indicating communication situations at the plurality of timings, and a communication device control unit which controls the communication device transmission unit such that the communication device transmission unit communicates with the relay device at one of the plurality of timings, the communication situation of which is good and which is identified on the basis of the communication situation information, and the relay device includes a relay device reception unit which receives the respective test signals at the plurality of timings, a measurement unit which measures the respective communication situations at the time of reception of the test signals at the plurality of timings, a relay device control unit which generates the communication situation information on the basis of the communication situations, and a relay device transmission unit which transmits the communication situation information to the communication device during a time frame when communication with the communication device is possible.

Apparatuses and methods for communication in non-terrestrial networks are provided. Downlink transmission from a satellite node is received (300). Pathloss of uplink transmission to the satellite node is estimated (302). Based on the path loss, it is determined (304) whether uplink transmission of the apparatus can reach the satellite node and uplink transmission suspended (306) if determination indicates that the transmission will not reach the node.

This application provides a polarization reconfiguration method and a communication apparatus. A network device may send polarization pre-switching indication information to appropriately schedule and adjust user polarization within a base station or between base stations. A terminal device may switch a polarization mode in advance based on the polarization pre-switching indication information sent by the network device.

Systems and methods are disclosed herein for uplink power control in a cellular communications network that are particularly well-suited for flying wireless devices (e.g., aerial User Equipments (UEs)). In some embodiments, a method performed by a wireless device for uplink power control comprises receiving, from a base station, reference altitude information comprising one or more height thresholds and detecting that a height of the wireless device is above a height threshold. The method further comprises triggering and sending a measurement report to the base station upon detecting that the height of the wireless device is above the height threshold, and receiving, from the base station, an indication to use a particular one of two or more fractional pathloss compensation factors for uplink power control. The two or more fractional pathloss compensation factors for uplink power control comprise one or more wireless device specific fractional pathloss compensation factors.

A method and system for finding the true geolocation coordinates of User Equipment (UE) using a communication network and system based on Non-Terrestrial Network (NTN). The system uses precision clock signals of a UE and satellites in an NTN. Using the time of arrival method disclosed in the invention, a trusted satellite can compute the location of a UE by processing positioning signals. Consequently, satellites accurately compute the true location of UE and store it on satellites in the space and/or database server connected with the ground station. The invention enables accurate delivery of shipments in a logistic network.

The present disclosure relates to a communication method and system for converging a 5.sup.th-Generation (5G) communication system for supporting higher data rates beyond a 4.sup.th-Generation (4G) system with a technology for Internet of Things (IoT). The present disclosure may be applied to intelligent services based on the 5G communication technology and the IoT-related technology, such as smart home, smart building, smart city, smart car, connected car, health care, digital education, smart retail, security and safety services. Accordingly, the embodiments herein provides a method and system method for handling a random access procedure in a Non-Terrestrial communication system (300). The method includes obtaining, by a UE (100), a default TA, a RACH resource, and a RACH configuration list. Further, the method includes selecting, by the UE (100), the default TA and the RACH resource. Further, the method includes applying, by the UE (100), the selected default TA to the random access procedure. Further, the method includes performing, by the UE (100), the random access procedure based on the selected RACH resource and the selected default TA. The proposed method can be used to reduce the CP and GT in the RACH preambles, so as to optimize the random access procedure using the default TA.