Method and apparatus for reducing call setup delay

A subscriber device operating in a wireless communications network and capable of entering a power-saving mode, the subscriber device comprising:

• a memory;
• a transceiver;
• and
• a processor configured to:
• cause the subscriber device to operate in a low-power state in which at least one wireless link is disconnected from a wireless data network, via the transceiver, and in which the wireless link is periodically temporarily re-established, via the transceiver, to check for pending transmissions at a first reduced frequency before re-entering the disconnected state in response to finding no pending data transmissions;
• and
• in response to detecting an association, or change an 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, cause the subscriber device to transition to a higher-power state and transmit data messages, via the transceiver, 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.