A coexistence mechanism for arbitrating between performing operations associated with a first network device and performing operations associated with a second network device coupled to the first network device. The start time of a scheduled operation associated with a second network device is determined based, at least in part, on an activity report message received at a first network device from the second network device. A scheduled operation associated with the first network device is performed if the scheduled operation associated with the first network device can be performed prior to the start time of the scheduled operation associated with the second network device. Otherwise, the priority of the scheduled operation associated with the first network device is compared to the priority of the scheduled operation associated with the second network device to determine whether to grant control of the transmission channel to the first or second network device.