An approach for inter-gateway interference estimation and admission control is provided. A gateway receives return link signals, each being received via a satellite from a respective user terminal (UT) located within a satellite beam serviced by the gateway. A transmit power factor and an interference factor are determined for each UT based on the respective return link signal. A total interference factor is determined for the UTs based on the transmit power factors and the interference factors. A residual capacity level for the satellite beam is determined based on the total interference factor and a noise power factor. The gateway receives an admission request from a further UT requesting admission for transmission of a return link signal. The gateway determines whether to grant the admission request based on a required capacity level for the return link signal of the further UT relative to the residual capacity level.

A terminal apparatus is provided. The terminal apparatus obtains synchronization signal and physical broadcast channel (PBCH) blocks (SSBs) in a plurality of beams; then determines a target beam in the plurality of beams based on an association relationship between an SSB index and a first random access preamble, where the first random access preamble is determined based on a cyclic shift and/or an order of symbols; and finally sends the random access preamble by using the target beam to initiate a random access request. A communication device receives the first random access preamble in the random access request sent by the terminal apparatus, and then, determines, based on the association relationship, the target beam accessed by the terminal apparatus. The first random access preamble is determined based on the cyclic shift and/or the order of symbols.

One disclosure of the specification provides a method performed by UE. The method comprises the steps of: receiving a synchronization signal from a network; on the basis of the UE being connected to a base station via an NTN satellite, receiving, from the network, system information related to an NTN; transmitting a RACH to the network; receiving a RA response message from the network; receiving measurement information from the network, wherein the measurement information includes information regarding a measurement point in time for measurement by the UE; determining, on the basis of orbit information of a target satellite, a measurable point in time when an elevation angle of the target satellite exceeds a threshold value; on the basis of the measurement point in time being earlier than the measurable point in time, transmitting a failure message to the network; and carrying out measurement at the measurable point in time.

Systems, devices, and methods for determining and establishing frequency-dependent gain compensation in wide bandwidth communication systems are disclosed. Variable frequency-dependent gain compensation circuits, or variable equalizers, have settings that configure them to establish discrete frequency-dependent gain compensation. The frequency-dependent gain compensation can include various types and levels of gain slope and/or ripple. The settings of the variable equalizers can be set by control signals established a control circuit in response to signals from an external computer. The variable equalizers are coupled to other circuits or devices and the frequency-dependent gain of the combined circuit are measured. The settings of the variable equalizer are then changed to establish an optimal frequency-dependent gain profile or frequency-dependent gain that is closest to a predetermined frequency-dependent target gain profile. The settings can then be saved in a memory or register.

A mobile satellite radio equipped with a phased array antenna configures the phased array antenna in one or more non-directional operating modes in order to initially detect a signal from a communication satellite. Once a signal has been received from the satellite, frequency information determined in the course of operating in the one or more non-directional modes is used to configure the mobile satellite radio for operation in a subsequent stage when the phased array antenna is configured in a directional mode. In the subsequent stage the phased array antenna is used to scan a solid angle space to determine the direction of the satellite. Thereafter the antenna is used in the directional mode for satellite communication.

A method of operating a communications device for transmitting signals to and/or receiving signals from a non-terrestrial network (NTN) apparatus of a wireless communications network. The communications device acquires information for synchronising a transmission with the NTN apparatus. The communications device estimates a time remaining until an expiry time at which the information for synchronising the transmission with the apparatus will become invalid. The communications device receives, from the NTN apparatus, a biasing signal providing an indication to the communications device to bias an estimate of a time required to communicate the transmission with the NTN apparatus. The communications device determines, based at least in part on the indication provided by the biasing signal, the biased estimate of the time required to communicate the transmission with the NTN apparatus.

Various example embodiments relate to devices and methods for refining a coverage window for discontinuous coverage. A terminal device may comprise at least one processor and at least one memory including computer program code. The at least one memory and the computer program code may be configured to, with the at least one processor, cause the terminal device to perform actions including determining a coverage window for receiving transmission from a network device, monitoring radio coverage of the network device at least during the coverage window, and updating the coverage window based on when the radio coverage is available for the terminal device.

This application provides a satellite communication method and apparatus. A terminal obtains a level-1 broadcast signal from a satellite, where a beam status corresponding to the level-1 broadcast signal is an energy saving state, and the level-1 broadcast signal includes synchronization information. The terminal obtains a level-2 broadcast signal from the satellite, where a beam status corresponding to the level-2 broadcast signal is a broadband communication state. The terminal communicates with the satellite based on the level-2 broadcast signal.

Systems, devices, and methods for determining and establishing frequency-dependent gain compensation in wide bandwidth communication systems are disclosed. Variable frequency-dependent gain compensation circuits, or variable equalizers, have settings that configure them to establish discrete frequency-dependent gain compensation. The frequency-dependent gain compensation can include various types and levels of gain slope and/or ripple. The settings of the variable equalizers can be set by control signals established a control circuit in response to signals from an external computer. The variable equalizers are coupled to other circuits or devices and the frequency-dependent gain of the combined circuit are measured. The settings of the variable equalizer are then changed to establish an optimal frequency-dependent gain profile or frequency-dependent gain that is closest to a predetermined frequency-dependent target gain profile. The settings can then be saved in a memory or register.

A satellite communications system for communicating at a first frequency slot with first and second pairs of satellite transponders in linear polarization format. The system comprises a first terminal, a second terminal and a station. The first terminal receives at least one first input signal and concurrently radiates a first output signal at the first frequency slot to the first and second pairs of satellite transponders via a first beam and a second beam, respectively, in right-hand circularly polarized format. The second terminal receives at least one second input signal and concurrently radiates a second output signal at the first frequency slot to the first and second pairs of satellite transponders via a third beam and a fourth beam, respectively, in left-hand circularly polarized format. The station receives four satellite signals from the first and second pairs of transponders and recovers the at least one first input signal and the at least one second input signal using wavefront multiplexing technique.