A power-saving enabled subscriber device operates in a low-power state in which at least one wireless link is disconnected from a wireless data network and in which the wireless link is periodically temporarily re-established to check for pending transmissions at a first reduced frequency before re-entering the disconnected state in response to finding no pending data transmissions. To reduce delays in setting up a new call to the subscriber device, and responsive to detecting an association, or change in association, of the subscriber device with one of (i) a particular geographic region, (ii) a particular role at a particular geographic region, and (iii) a particular talk group, the subscriber device transitioning the subscriber device to a higher-power state and transmitting data messages over the wireless link at a second increased frequency to cause the subscriber device to remain in a connected state more often compared to the low-power state.