There seems to be quite a bit of confusion about what has taken place. These are two
separate systems that share a single Smartzone master controller via a microwave hop.
The Forsyth talkgroups will be rarely heard on Cobb sites once the testing and massive reprogramming of subscriber radios on the Forsyth leg are complete, and you will rarely hear any Cobb TG's active on the Forsyth zone, as Cobb officers rarely move out of coverage of their home system into the coverage of Sawnee mountain.
The whole reason Forsyth talkgroups had to be changed was to prevent duplicates that were already in use on the Cobb zone. The UID's also had to be changed because of this, and to enable wide area roaming.
I think it is important (for scanner users) not to be confused when programming their scanners, and thus, the Forsyth and Cobb systems should be listed separately. They do after all, have different RFSS ID's, only the same WACN (as do most Astro 25 networks installed by Motorola in the Atlanta area, for future use of course).
For those unfamiliar, read up on how Smartzone OmniLink roaming works in an Astro 25 system, while this document was prepared for UCAN statewide DTRS in Utah, it's basic principles can be applied here:
http://siec.utah.gov/omnilink/documents/OmniLinkTraining.pdf
The key concept is DSA, Dynamic Site Assignment of talkgroups, which is what you experience as a scanner user when you start hearing Forsyth county talkgroups on "Cobb's" system and vice versa. This is the "roaming" between home zones function in action.
You will only hear Cobb talkgroups on FSY sites when the following conditions occur:
1)-a Cobb user who's radio is authorized for wide area roaming enters the coverage area of a Forsyth site, and either manually (from his/her radio) or automatically (if his/her radio is programmed) registers with the network on that roaming site.
2)-DSA will then occur, and the desired talkgroup that wide area user is using will be directed to the roaming zone, so if you are listening on a scanner in that zone, that talkgroup would then become active with that users "home" zone traffic.
3)-DSA will stay in place so long as: the roamer stays registered on the distant site, or if the system is placed into multi-zone simulcast by the system management. DSA will end when the roaming user de-registers, or after a set period of time by the system manager (usually 12-24 hours).
The same is true of Cobb talkgroups on the Forsyth sites. Only when a user requests, or system management institutes this, will you hear Cobb traffic.
This is to conserve RF channel resources on all zones (why bother sending it if no one is listening?)
I hope this clears up the confusion. You Forsyth folks should keep your Forsyth system in a separate bank, and only add the Cobb talkgroups if you're curious when a Cobb user roams onto your sub system and vice versa.
Again, these are two
separate sub systems that share a zone controller that enables roaming between the two. In the future, it is possible that other systems become sub systems and join in. (Easier said than done...herding cats anyone?)