What To Do When in Site Trunking

From the Dispatcher perspective:

  1. If you are utilizing a Wire Line console, you should have at least one (1) portable or mobile radio as a backup to your console and as an indicator of Site Trunking conditions at a site in your immediate area.  Even with a stand-alone radio in the dispatch center however, you still may not be aware of a site being in Site Trunking if that site is some distance from your location.
  2. If you are utilizing an RF console configuration, you should have at least two (2) radios on separate external antennas, pointed toward different sites.  Each of these radios should be “dumbed down” to a SmartNet configuration to keep it from being able to find another site and then locked on to that single, different site.  One of the sites selected should be the closest site.  The other site can be one of multiple sites available at farther distance.  The common feeling is that console radios should be able to access different sites, as needed, as appropriate.  This is not the configuration you want to utilize to minimize the impact of Site Trunking!  

The dispatcher should now be equipped with the ability to talk to both the users who are affiliated with Wide Area sites and the few who may remain affiliated with the local site when it is in Site Trunking.  This configuration may need to be duplicated depending on the number of console locations, the number of radios linked to the console(s) and the number of talkgroups that need to be monitored in your dispatch center.

From this configuration (dependent upon the console resources available), it may be possible for a dispatcher(s) to create a temporary console patch between both the Wide Area and the Site Trunking sides of the conversations.

Available resources may also allow the dispatcher to SimulSelect both radios to dispatch to both scenarios at once.

From the field user perspective:

  1. If your normal jurisdictional area precludes that most of your users will normally be affiliated with the same site as your RF dispatch consoles, you may want to consider having your radios programmed with a SITE LOCK button.  When activated, this feature keeps the radio affiliated with the site the user is affiliated with at the time of activation even if that site is in Site Trunking.  If our communications plan so dictates, users could lock on to the Site Trunking site along with the dispatch console and normal communications can occur without the user radios wandering to another site.  
  2. Should you elect to program this feature, users must also be trained to not LOCK their radio under normal operation or their radio will remain on a single site and will not roam from site to site as normal.  

From the system perspective:

There are several system adjustments that IPSC can make to profiles of identified, local talkgroups that could potentially lessen the impact of Site Trunking to the local user community.  However, to make this remedy effective, it is imperative that agencies work with IPSC to determine:

  1. The IPSC site which provides the best overall coverage within the designated agency’s service area, and
  2. One or more agency designated talkgroups to which IPSC will apply a profile that will make those talkgroups only active on the site designated in (1) above.
  3. Policies are developed within the agency to move users to the designated talkgroup(s) for the duration of the Site Trunking event.