FIG. 22 is a schematic structural diagram 4 of an apparatus embodiment for adding a secondary serving cell according to the present invention. As shown in FIG. 22, the terminal includes an eleventh unit 211A, a twelfth unit 212A, a thirteenth unit 213A, and a fourteenth unit 214A. The eleventh unit 211A is configured to receive a notification message sent by a primary base station, where the notification message includes a serial number of a random access preamble code and a serial number of a physical random access channel mask code. The twelfth unit 212A is configured to send a random access request message to a secondary base station by using a sending resource that is determined according to the serial number of the physical random access channel mask code, where the random access request message includes the random access preamble code that is determined according to the serial number of the random access preamble code. The thirteenth unit 213A is configured to receive a random access response message sent by the secondary base station, where the random access response message includes a time advance command TAC that is determined by the secondary base station according to the random access request message. The fourteenth unit 214A is configured to adjust, according to the TAC, time advance TA of the terminal on a secondary serving cell corresponding to the secondary base station.
