摘要 |
A base station configures a primary cell group and at least one secondary cell group in a wireless device. The wireless device transmits first uplink signals in the secondary cell group employing a reference secondary cell in the secondary cell group as a timing reference. The wireless device autonomously selects a new activated secondary cell in the secondary cell group as the timing reference. The new activated secondary cell is different from the reference secondary cell. The wireless device transmits second uplink signals in the secondary cell group employing the new activated secondary cell as the timing reference.
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