Abstract: A semiconductor package includes electrically connected first to third semiconductor chips, stacked in a vertical direction; an encapsulant on the first semiconductor chip and encapsulating a portion of each of the semiconductor chips; and external connection bumps below the first semiconductor chip and being electrically connected to the semiconductor chips, wherein the semiconductor chips each include a plurality of lower pads, the first and second semiconductor chips each include a plurality of upper pads including a first group of upper pads and a second group of upper pads, and through-electrodes electrically respectively connecting the upper pads and the lower pads, and the through-electrodes include a first group of through-electrodes respectively connected to the first group of upper pads, and a second group of through-electrodes connected to upper pads that are electrically connected to each other of the second group of upper pads.

Abstract: Disclosed is a communication method performed between a satellite and a ground station and apparatuses performing the communication method. The communication method includes transmitting a plurality of frames based on a beam allocation time schedule (BATS) between a satellite and a ground station, and synchronizing the BATS based on a reception time and a detection time of one or more frames among the plurality of frames to be received through a beam open window (BOW) allocated to the ground station.

Abstract: Disclosed is a communication method performed between a satellite and a ground station and apparatuses performing the communication method. The communication method includes transmitting a plurality of frames based on a beam allocation time schedule (BATS) between a satellite and a ground station, and synchronizing the BATS based on a reception time and a detection time of one or more frames among the plurality of frames to be received through a beam open window (BOW) allocated to the ground station.

Abstract: Disclosed is a network synchronization apparatus and method of a time division multiple access (TDMA)-based mesh network satellite communication system, the network synchronization method of a terminal in a satellite communication system including receiving timing error information from a central station, generating a mesh superframe start time (SST?) by reversing a sign of the timing error information, and receiving traffic information transmitted by a transmission terminal using the mesh SST?.

Abstract: Disclosed is a network synchronization apparatus and method of a time division multiple access (TDMA)-based mesh network satellite communication system, the network synchronization method of a terminal in a satellite communication system including receiving timing error information from a central station, generating a mesh superframe start time (SST?) by reversing a sign of the timing error information, and receiving traffic information transmitted by a transmission terminal using the mesh SST?.