We understand that. What were are seeing are not necessarily calls at or close to the county lines. They are totally different TGs on the Loudoun system. I think maybe what you're thinking about is for example Loudoun is responding to FFX for mutual aid that will switch their radios over to the TG on the FFX sysyem.
See the other posts about this too. Might be a little clearer expmination.
Sent from my SM-G930V using Tapatalk