Rangecast FAQ
[FAQ-1256] Trunk system patch channels



Trunked systems can operate patches (temporarily connecting users across multiple talkgroups). Unlike normal communications, patches are not associated with any single specific talkgroup, so patch transmissions are not indexed to a specific channel in Rangecast. Instead, patches are associated with a pseudo-channel corresponding to the trunking broadcast tower carrying the patch. The channel ID format for patch traffic is like TL12345 where the number is a tower ID.


In Rangecast, all transmissions are associated with a single channel. In the special case of patch traffic (which on a trunked radio system activates radios on multiple talkgroups) there is no specific single channel to which transmissions can be tied.

Therefore patch traffic is assigned to a special channel ID corresponding to the trunking system broadcast tower where the recorded traffic originated. The patch channel has an ID that beings with TL followed by the five-digit tower ID from the Radio Reference database. All patch traffic originating on that tower will be carried on the same Rangecast channel ID, regardless of which specific talkgroups participate in each patch.

These patch channels are not listed in the Rangecast channel database. The programming determines which towers are monitored, and any patch traffic on a monitored tower will be automatically routed to the appropriate patch channel based on the tower ID.


Patch transmissions are detected and recorded by Rangecast feed site scanners when at least one participating talkgroup is in the scan list. However, when the scanner reports the transmission to the PC, it may show the talkgroup code of any participating channel (not necessarily one in the scan list.) All transmissions of this type are categorized as patches on the tower, with no attempt to further narrow the talkgroup list, because the transmission patch may include multiple talkgroups from among those selected for reception, without the scanner providing the PC with information to identify these specific talkgroups.



Rangecast FAQ - ID 1256 - last updated 26 March 2019     Images shown - [block]