The present invention relates to a method and an apparatus used for communication, including: when a base station receives downlink data through a first system bearer of a first user equipment, detecting, by the base station, according to a context of the first user equipment stored by the base station itself, whether a radio bearer which is of other user equipment except the first user equipment and assists the first user equipment or the first system bearer in transmitting data exists in the base station; if the radio bearer exists, selecting, by the base station, from the first user equipment and the other user equipment except the first user equipment, at least one user equipment that transmits the downlink data; and sending, by the base station, the downlink data through a specified radio bearer corresponding to the at least one user equipment.