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The Regional Advisory Committee (RAC), Owners and Operators Committee, and Users Group are all meeting on Thursday May 20th.

 
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A radio topography that dynamically allocated resources to users. It is a group of repeaters that can be used by several different and separate agencies. These agencies all have their own separate groupings (called "talkgroups") where they communicate only with users in their own agency. There are also talkgroups where users from different agencies/disciplines can interoperate when the need arises. This interoperability is one of the key strengths of the trunked system.

Advantages:

  1. Users have all of the benefits of a repeated radio system.
  2. Dozens or hundreds of talk group are available to groups of users that currently don't have their own channel.
  3. Talkgroups are prioritized. If there is a shortage of repeaters. Users of a lower priority have to wait until communications of a higher priority are complete.
  4. No doubling is possible. The system allocates a repeater for a talkgroup, and if someone else is talking when another user attempts to transmit, the second user is given a warning tone on their radio, indicating they cannot transmit.
  5. Emergency priority. If a user has an emergency and presses their emergency button. The system immediately gives that user priority on their "main" channel. Any conversation that was in progress at the time of the emergency is preempted.

Disadvantages:

  1. Requires an infrastructure. Some areas may not be serviced, due to distance to the trunking site(s).
  2. System delays: Since the system dynamically allocates resources, and checks for other transmissions in progress on the requested talkgroup, there is a brief delay as the system allocates resources and assigns users in a talkgroup to a repeater channel. This delay is approximately 0.3 - 0.5 seconds. This delay is similar to delays found in conventional repeaters.
  3. If the system, or supporting infrastructure (microwave, leased phone lines, other radio links) fail, some or all of the users will lose some level of service. This service impairment may include reduced service area, reduced system resources (channels), limited/loss of communications with other users, limited/loss of communications with dispatchers, or a total loss of communications. In a distributed trunked radio system, such as in the Minneapolis/St. Paul metro area, St. Cloud/Stearns, or Rochester/Olmsted a total system failure is extremely unlikely. There are several levels of redundancy, and several "fallback" modes in the event of system degradation.
 
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