Trunked Radio Systems

1
Trunked Radio Systems

• Austin Stanhope

2
Overview

• Conventional Radio Systems
• - How Repeaters Work
• - Channel Assignments
• Migration to Trunked Radio
• - Channel Assignments
• Pros/Cons of Trunked Radio
• Trunked Radio Audio Sample

3
Conventional Radio Systems

• How Repeaters Work
• Extend range of radio communications
• Allow distant weak radio signals to be
  repeated as stronger signals
• Transmit on frequency A
• Receive on frequency B
• Each channel takes up two frequencies

4
Conventional Radio Systems

• Channel Assignments
• Each agency needs multiple channels (Police,
  Fire, Sheriff, etc)
• RPD North
• RPD South
• RPD Records
• RPD Swat
• A few more Tac channels
• Washoe County public safety/services agencies
  require about 200 channels

5
Migration to Trunked Radio

• Not all 200 channels have simultaneous traffic
  (max 10-15).
• TRS dynamically assigns frequencies to be used
  upon request.
• Control channel transmits frequency and talkgroup
  data to radios.
• 200 conventional frequencies 15 TRS frequencies

6
Migration to Trunked Radio

• Channel Assignments
• A channel in a TRS is called a talkgroup
• More talkgroups may be added without reserving
  more frequencies
• Each agency still has their own talkgroup(s)

7
Pros/Cons of Trunked Radio

• Pros
• Less frequencies used
• Easy interagency communication
• All agencies on one convenient system

• Cons
• Weaker signals, less range (800MHz)
• Maintenance required (system downtime)
• High talkgroup traffic ties up the system
  (natural disasters)

8
Conclusion

• Conventional Radio Systems
• - How Repeaters Work
• - Channel Assignments
• Migration to Trunked Radio
• - Channel Assignments
• Pros/Cons of Trunked Radio
• Trunked Radio Audio Sample

9
Trunked Radio Audio Sample

• Reno Fire emergency service call page/tone-out.
• Presentation posted at www.cse.unr.edu/stanhope
• For more information www.radioreference.com