A method for satellite communication over non-geosynchronous orbit (NGSO) satellites, using a terminal having a non-tracking antenna, is presented. The terminal may communicate with an NGSO satellite each time the NGSO satellite passes through the terminal's antenna beam (communication opportunity). Though the communication opportunities are short and may reoccur at relatively long intervals (e.g., minutes to tens of minutes), these communication opportunities may be sufficient for transmitting the volumes of information generated by Internet of Things (IoT) applications during the intervals between communication opportunities.

A method for synchronizing a network device includes: receiving, by the network device, a first SSM and a second SSM, where the first SSM carries a first SSM code for indicating a quality level of a first clock source and a first eSSM code for indicating the quality level of the first clock source, and the second SSM carries a second SSM code for indicating a quality level of a second clock source and a second eSSM code for indicating the quality level of the second clock source. When a value of the first SSM code is less than a value of the second SSM code, the network device calibrates a frequency of the network device based on a timing signal of the first clock source.

In one implementation, a method for a solar cell array is provided, the method includes emitting a communication message from the solar cell array by reverse biasing the solar cell array so as to cause at least a portion of the solar array to emit a detectable amount of radiation corresponding to the communication message. In one embodiment a solar cell array circuit is provided including a solar string comprising a plurality of solar cells coupled together, a charge storage device coupled to a power bus, and a bidirectional boost-buck converter having a first and second pair of MOSFETs connected in series between positive and negative rails of the power bus with an inductor coupled from between the first and second paired MOSFETs to a charging output of the solar string.

A wireless communication system includes: a first wireless communication apparatus; and a second wireless communication apparatus. First wireless communication apparatus wirelessly communicates with second wireless communication apparatus using one or more first antennas. Second wireless communication apparatus wirelessly communicates with the first wireless communication apparatus using one or more second antennas. A controller included in the wireless communication system performs control to change one or both of first antennas wirelessly communicating with the second wireless communication apparatus among the one or more first antennas of a plurality of first wireless communication apparatuses or second antennas wirelessly communicating with the first wireless communication apparatus among a plurality of second antennas of the second wireless communication apparatus for maximizing communication quality on the basis of the communication quality for each time between first antenna and second antenna calculated using a position of the one or more second antennas and movement schedule information representing a position of first wireless communication apparatus for each time.

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.

A large-scale network node simulation method based on Linux container is provided, which solves problems of low packet transmission efficiency and multi-thread creation in real-time simulation in a large-scale network scenario. The method includes: scheduling all container nodes in a scenario; managing, by a container node, a dynamic thread through an idle thread management queue, and setting a finite state machine and a function pointer for the dynamic thread; registering, by a source container node, an output queue with a next-hop container node, and informing the next-hop container node to allocate a dynamic thread for receiving and processing the output queue. Packet transmission is realized between the container nodes through data units created in a shared memory. The sending thread and the receiving thread dynamically adjust the number of dynamic threads by checking the state of the output queue.

This disclosure provides systems, devices, apparatus, and methods, including computer programs encoded on storage media, for GNSS validity reporting in NTNs. A UE may transmit, to a network entity, a report of a validity duration for GNSS tracking information. The GNSS tracking information may be associated with an NTN including the UE and the network entity. The report may include an indication of a remaining time period of the validity duration based on a threshold. The UE may switch to an RRC idle mode based on the report of the validity duration. The RRC idle mode may be switched to after an expiration of the remaining time period of the validity duration or based on an RRC release message received from the network entity.

An illustrated embodiment disclosed herein is a method for downlink scheduling. The method includes scheduling, by a satellite, one or more protocol data units (PDUs) in a slot, determining, by the satellite, whether available capacity of the slot is less than a predetermined threshold, responsive to determining that the available capacity of the slot is not less than the predetermined threshold, scheduling, by the satellite, a second one or more PDUs in the slot, and responsive to determining that the available capacity of the slot is less than that the predetermined threshold, transmitting, by the satellite, the slot to an endpoint. In some embodiments, the one or more PDUs are associated with a first spreading factor (SF). In some embodiments, the first SF is lower than a second SF. In some embodiments, the second one or more PDUs are associated with the second SF.

Methods and systems are described for providing end-to-end beamforming. For example, end-to-end beamforming systems include end-to-end relays and ground networks to provide communications to user terminals located in user beam coverage areas. The ground segment can include geographically distributed access nodes and a central processing system. Return uplink signals, transmitted from the user terminals, have multipath induced by a plurality of receive/transmit signal paths in the end to end relay and are relayed to the ground network. The ground network, using beamformers, recovers user data streams transmitted by the user terminals from return downlink signals. The ground network, using beamformers generates forward uplink signals from appropriately weighted combinations of user data streams that, after relay by the end-end-end relay, produce forward downlink signals that combine to form user beams.

User equipment (UE) access to a non-terrestrial network (NTN) via a satellite to a Fifth Generation (5G) public land mobile network (PLMN) is supported using fixed tracking areas (TAs) and fixed cells. The fixed TAs and fixed cells are defined in the NTN independently of NTN radio cells. Network elements in the NTN are provided with configuration information for the fixed TAs and fixed cells from a server (e.g., an Operations and Maintenance (O&M) server). The configuration information includes location related information for the fixed TAs and fixed cells, which may not be standardized. The network entities perform one or more services for the UE based on the location related information for the fixed TAs and fixed cells, such as determining a fixed TA or fixed serving cell for a UE, locating the UE, routing emergency calls, and supporting wireless emergency alerting (WEA).