A method for synchronization comprising: determining, by a network equipment, that a first terminal is not able to be synchronized with a satellite system; determining, by the network equipment, a present position of the first terminal; selecting, by the network equipment, a second terminal according to the present position of the first terminal; and indicating (120, 220), by the network equipment, the second terminal to send a satellite-system-based synchronization signal by which the first terminal is synchronized with the satellite system; wherein determining, by the network equipment, that the first terminal is not able to be synchronized with the satellite system by: receiving, by the network equipment, a first message sent by the first terminal, the first message indicating that the first terminal is not able to be synchronized with the satellite system; and determining, by the network equipment, that the first terminal is not able to be synchronized with the satellite system according to the first message; wherein indicating, by the network equipment, the second terminal to send the satellite-system-based synchronization signal comprises: indicating the second terminal through a broadcast channel to send the satellite-system-based synchronization signal, wherein the second terminal is a terminal which is located within a second region and which detects a satellite signal having strength equal to or greater than a strength threshold, and a distance between a position within the second region and the present position of the first terminal is equal to or shorter than a second predetermined distance. determining, by a network equipment, that a first terminal is not able to be synchronized with a satellite system; determining, by the network equipment, a present position of the first terminal; selecting, by the network equipment, a second terminal according to the present position of the first terminal; and indicating (120, 220), by the network equipment, the second terminal to send a satellite-system-based synchronization signal by which the first terminal is synchronized with the satellite system; wherein determining, by the network equipment, that the first terminal is not able to be synchronized with the satellite system by: receiving, by the network equipment, a first message sent by the first terminal, the first message indicating that the first terminal is not able to be synchronized with the satellite system; and determining, by the network equipment, that the first terminal is not able to be synchronized with the satellite system according to the first message; wherein indicating, by the network equipment, the second terminal to send the satellite-system-based synchronization signal comprises: indicating the second terminal through a broadcast channel to send the satellite-system-based synchronization signal, wherein the second terminal is a terminal which is located within a second region and which detects a satellite signal having strength equal to or greater than a strength threshold, and a distance between a position within the second region and the present position of the first terminal is equal to or shorter than a second predetermined distance. receiving, by the network equipment, a first message sent by the first terminal, the first message indicating that the first terminal is not able to be synchronized with the satellite system; and determining, by the network equipment, that the first terminal is not able to be synchronized with the satellite system according to the first message; wherein indicating, by the network equipment, the second terminal to send the satellite-system-based synchronization signal comprises: indicating the second terminal through a broadcast channel to send the satellite-system-based synchronization signal, wherein the second terminal is a terminal which is located within a second region and which detects a satellite signal having strength equal to or greater than a strength threshold, and a distance between a position within the second region and the present position of the first terminal is equal to or shorter than a second predetermined distance.