A network device and UE determine that the UE is handed over from a first network device to a second network device, and in a handover process, the first network device or the second network device sends a feedback control message to the UE to query for a quantity of fountain codes that are needed to continue to send, and the second network device continues to perform encoding according to the quantity of fountain codes that are needed to continue to send, and sends encoded data to the UE. In an uplink process, the UE sends a feedback control to the second network device and obtains a quantity of data packets that are needed to continue to encode, and sends a first data packet to the second network device. A receive end performs decoding according to the received first data packet to obtain an original data packet.