Scanning talkgroups

1. A method, comprising:

receiving, at a communication device, an instruction to enter a scanning mode, the communication device permitted to participate in a plurality of talkgroups;

receiving, at the communication device, control channel information;

wherein the control channel information includes respective aggregate lengths of time that a plurality of other communication devices have been in a dedicated transmission mode;

in response to receiving the instruction to enter the scanning mode, determining that at least a first one of the plurality of talkgroups is active, using the control channel information;

in response to determining that at least one of the plurality of talkgroups is active, setting the communication device to a first active talkgroup of the plurality of talkgroups;

determining that a predetermined time has passed since the communication device was set to the first active talkgroup;

in response to determining that the predetermined time has passed since the communication device was set to the first active talkgroup, determining that at least a second one of the plurality of talkgroups, other than the first active talkgroup, is active; and

in response to determining that the second talkgroup is active, setting the communication device to the second active talkgroup of the plurality of talkgroups.

2. The method of claim 1 , wherein:

determining that at least one of the plurality of talkgroups is active comprises determining that a particular talkgroup is active based on the information from the control channel indicating that the particular talkgroup is active; and

setting the communication device to the first active talkgroup of the plurality of talkgroups comprises setting the communication device to the particular talkgroup, as the first active talkgroup, in response to determining that the particular talkgroup is active.

3. The method of claim 1 , further comprising:

displaying, on the communication device, a list of at least some of the plurality of talkgroups including, for each active talkgroup of the plurality of talkgroups that is displayed in the list, an indicator identifying the active talkgroup as an active talkgroup.

4. The method of claim 3 , further comprising:

receiving, at the communication device, a selection of a selected one of the plurality of talkgroups from the list displayed on the communication device, the selected one of the plurality of talkgroups being identified as an active talkgroup by an indicator included in the list; and

setting the communication device to the selected one of the plurality of talkgroups in response to receiving the selection of the selected one of the plurality of talkgroups.

5. The method of claim 1 , further comprising:

determining, while the communication device is set to the second active talkgroup, that the second active talkgroup has become inactive;

in response to determining that the second active talkgroup has become inactive, determining that none of the plurality of talkgroups is active; and

in response to determining that none of the plurality of talkgroups is active, providing a notification that none of the plurality of talkgroups is active.

6. The method of claim 1 ,

wherein, in the process of determining that the predetermined time has passed since the communication device was set to the first active talkgroup, the predetermined time is based on a priority level associated with the first active talkgroup.

7. A communication device permitted to participate in a plurality of talkgroups, the communication device comprising:

one or more processors, wherein the one or more processors are configured to:

receive an instruction for the communication device to enter a scanning mode;

receive control channel information;

wherein the control channel information includes respective aggregate lengths of time that a plurality of other communication devices have been in a dedicated transmission mode;

in response to receiving the instruction to enter the scanning mode, determine that at least one of the plurality of talkgroups is active using the control channel information;

in response to determining that at least one of the plurality of talkgroups is active, set the communication device to a first active talkgroup of the plurality of talkgroups;

determine that a predetermined time has passed since the communication device was set to the first active talkgroup;

in response to determining that the predetermined time has passed since the communication device was set to the first active talkgroup, determine that at least a second one of the plurality of talkgroups, other than the first active talkgroup, is active; and

in response to determining that the second talkgroup is active, set the communication device to the second active talkgroup of the plurality of talkgroups.

8. The communication device of claim 7 ,

wherein the one or more processors, when determining that at least one of the plurality of talkgroups is active, are configured to determine that a particular talkgroup is active based on the information from the control channel indicating that the particular talkgroup is active; and

wherein the one or more processors, when setting the communication device to the first active talkgroup of the plurality of talkgroups, are configured to set the communication device to the particular talkgroup, as the first active talkgroup, in response to determining that the particular talkgroup is active.

9. The communication device of claim 7 , further comprising:

a display device,

wherein the one or more processors are configured to control the display device to display a list of at least some of the plurality of talkgroups including, for each active talkgroup of the plurality of talkgroups that is displayed in the list, an indicator identifying the active talkgroup as an active talkgroup.

10. The communication device of claim 9 ,

wherein the communication device is configured to receive a selection of a selected one of the plurality of talkgroups from the list displayed by the display device, the selected one of the plurality of talkgroups being identified as an active talkgroup by an indicator included in the list, and

wherein the one or more processors are configured to set the communication device to the selected one of the plurality of talkgroups in response to receiving the selection of the selected one of the plurality of talkgroups.

11. The communication device of claim 7 , wherein the one or more processors are configured to:

determine, while the communication device is set to the second active talkgroup, that the second active talkgroup has become inactive;

in response to determining that the second active talkgroup has become inactive, determine that none of the plurality of talkgroups is active; and

in response to determining that none of the plurality of talkgroups is active, provide a notification that none of the plurality of talkgroups is active.

12. The communication device of claim 7 ,

wherein, when the one or more processors determine that the predetermined time has passed since the communication device was set to the first active talkgroup, the predetermined time is based on a priority level associated with the first active talkgroup.

13. The communication device of claim 7 , wherein the communication device is a satellite communication device permitted to participate in a plurality of Push-to-Talk over satellite talkgroups.

14. The communication device of claim 7 , wherein the communication device is a cellular communication device permitted to participate in a plurality of Push-to-Talk over cellular talkgroups.

15. The communication device of claim 7 , wherein the communication device is a land mobile radio permitted to participate in a plurality of Push-to-Talk over land mobile radio talkgroups.

16. A non-transitory, computer-readable medium configured to store computer-readable instructions that, when executed by a processing device, instruct the processing device to perform a method comprising:

receiving, at a communication device, an instruction to enter a scanning mode, the communication device permitted to participate in a plurality of talkgroups;

receiving, at the communication device, control channel information;

wherein the control channel information includes respective aggregate lengths of time that a plurality of other communication devices have been in a dedicated transmission mode;

in response to receiving the instruction to enter the scanning mode, determining that at least one of the plurality of talkgroups is active using the control channel information;

in response to determining that at least one of the plurality of talkgroups is active, setting the communication device to a first active talkgroup of the plurality of talkgroups;

determining that a predetermined time has passed since the communication device was set to the first active talkgroup;

in response to determining that the predetermined time has passed since the communication device was set to the first active talkgroup, determining that at least a second one of the plurality of talkgroups, other than the first active talkgroup, is active; and

in response to determining that the second talkgroup is active, setting the communication device to the second active talkgroup of the plurality of talkgroups.

17. The non-transitory, computer-readable medium according to claim 16 , wherein

determining that at least one of the plurality of talkgroups is active comprises determining that a particular talkgroup is active based on the information from the control channel indicating that the particular talkgroup is active, and

setting the communication device to the first active talkgroup of the plurality of talkgroups comprises setting the communication device to the particular talkgroup, as the first active talkgroup, in response to determining that the particular talkgroup is active.

18. The non-transitory, computer-readable medium according to claim 16 , wherein the computer-readable instructions, when executed by the processing device, instruct the processing device to perform the method further comprising:

displaying, on the communication device, a list of at least some of the plurality of talkgroups including, for each active talkgroup of the plurality of talkgroups that is displayed in the list, an indicator identifying the active talkgroup as an active talkgroup.

19. The non-transitory, computer-readable medium according to claim 16 , wherein the computer-readable instructions, when executed by the processing device, instruct the processing device to perform the method further comprising:

determining, while the communication device is set to the second active talkgroup, that the second active talkgroup has become inactive;

in response to determining that the second active talkgroup has become inactive, determining that none of the plurality of talkgroups is active; and

in response to determining that none of the plurality of talkgroups is active, providing a notification that none of the plurality of talkgroups is active.

20. The non-transitory, computer-readable medium according to claim 16 ,

wherein, in the process of determining that the predetermined time has passed since the communication device was set to the first active talkgroup, the predetermined time is based on a priority level associated with the first active talkgroup.