A method, system and apparatus are disclosed. According to one or more embodiments, a method is performed by a wireless device The method includes: determining an activation or a deactivation of a first serving cell associated with a first physical channel; sending a corresponding Hybrid Automatic Repeat reQuest, HARQ, acknowledgment, ACK, in a second physical channel, a subcarrier spacing configuration of the first physical channel being different from a subcarrier spacing of the second physical channel; and performing a procedure related to the first serving cell based at least in part on a time offset, k, the time offset, k, being based at least in part on a reference physical channel.