In the embodiments of the present invention, UE can complete, by using only two interaction steps instead of six steps in the prior art, a process of sending a data packet to an eNodeB. Even a random access process in the six steps in the prior art includes four interaction steps, and by contrast, in the embodiments, signaling that needs to be consumed on an eNodeB when the UE sends data can be significantly reduced. This is relatively suitable for a scenario in which small data or occasional data is sent.