B when a radio is turned on it tries to affiliate with a site that it can receive. If it is programmed to use that site it can talk to the groups that it is authorized to use. The Elba site, the Enterprise Highschool site and the Enterprise downtown site are neighbors meaning that any radio talking to one will be heard on all three. So I guess the term roaming can be used here. I assume that Talk Group 5300, which is the NB vol fire group, is programmed to use all three. Each radio can be programmed to talk to different groups depending on need. I am not a trained technician but common sense tells me this should be right.
Mil