| 主权项 |
1. A base station comprising:
one or more processors; and memory storing instructions that, when executed, cause the base station to:
receive a buffer status report indicating an amount of data available for transmission in at least one uplink buffer of a wireless device;transmit, to the wireless device, a control command for transmission of a random access preamble on a secondary cell in a plurality of cells if the base station determines:
based on the buffer status report, that radio resources of the secondary cell are required for transmission of a portion of the data in addition to radio resources on a primary cell group; andthat the secondary cell requires a different uplink timing from currently activated and synchronized cells of the wireless device;receive, from the wireless device, the random access preamble on the secondary cell, the secondary cell being assigned to a secondary cell group, wherein transmission timing of the random access preamble is derived based, at least in part, on a first synchronization signal transmitted by the base station on the secondary cell group;transmit, to the wireless device, a random access response comprising a timing advance command for the secondary cell group; andtransmit at least one control packet comprising transport format information and resource allocation information for transmission of a plurality of packets of the data on the secondary cell. |
