A base station distributed unit receives information elements (IEs) from a base station central unit. The IEs comprise: at least one bearer configuration information element indicating that PDCP packet duplication is configured for at least one first bearer of a wireless device; and at least one information element indicating activation of the PDCP packet duplication of the at least one first bearer. The base station distributed unit transmits a medium access control control element indicating the activation of the PDCP packet duplication of the at least one first bearer to the wireless device in response to the at least one information element indicating the activation of the PDCP packet duplication. Based on the medium access control control element, the base station distributed unit receives: PDCP packets of the at least one first bearer; and duplicated PDCP packets of the at least one first bearer.