Division of Technology

Conventional Mutual Aid 800 MHz Repeater Plan

Purpose

To provide a plan for the implementation of shared public safety Mutual Aid Conventional 800MHz radio repeaters in South Carolina.
 

Objectives

  • Maximize the use of existing facilities.
  • Maximize the use of available frequencies.
  • Minimize frequency interference.
  • Provide for the sharing of equipment and sites.

Benefits

  • Provides for improved inter-agency communications.
  • Provides backup for 800MHz trunked radio systems.
  • Provides alternate 800MHz service for special events and emergencies.
All eligible local, state and federal public safety authorities shall have access to the shared public safety conventional 800MHz radio repeaters. Public safety authorities are defined as entities licensed in the Public Safety Radio Services and the Special Emergency Radio Service and their Federal counterparts.
 
Operation of fixed stations (base, mobile relay, RF control) on the Mutual Aid Channels requires coordination with the 800 MHz Advisory Committee, South Carolina Region 37 Committee approval and FCC licensing.
 
Use of the Mutual Aid Channels in mobile and portable radios does not require explicit South Carolina Region 37 Committee approval or FCC licensing, but all usage must be in accordance with FCC rules, the South Carolina Regional Plan and all state and local agreements for use of the channels.
 
There should be sufficient State provided and licensed shared public safety conventional 800MHz radio repeaters installed to provide statewide mobile coverage.
 
Where feasible and in coordination with existing 800 MHz systems, the State licensed shared public safety Mutual Aid Conventional 800MHz radio repeaters should utilize one of the five South Carolina Tactical 800MHz frequencies or National Public Safety Tactical frequencies.
 
The South Carolina Tactical (8SCTAC) frequencies are uniformly referred to by the following names:
 

BASE--Mobile
 NAME
TRANSMIT FREQUENCY
8SCTAC1 806.2250 851.2250
8SCTAC2 806.6875 851.6875
8SCTAC3 807.7750 852.7750
8SCTAC4 808.6375 853.6375
8SCTAC5 808.9750 853.9750

 

These National Public Safety Tactical frequencies are uniformly referred to by the following names:
 

BASE-Mobile
NAME
TRANSMIT FREQUENCY
8CALL90 806.0125 851.0125
8TAC91 806.5125 851.5125
8TAC92 807.0125 852.0125
8TAC93 807.5125 852.5125
8TAC94 808.0125 853.0125

 

In major population areas, coastal counties and those counties where both the State and Local Government utilizes 800MHz, additional repeaters should be installed so as to provide multi-channel repeater service. One of these repeaters should be on the 8CALL90 frequency of 806.0125. This channel should be monitored by a public safety dispatch center.
 
There should be at least one Local Government provided and licensed shared public safety conventional 800MHz radio repeater in each county of the state where 800MHz is the primary communications system for that local government. Where possible, county wide mobile coverage should be provided. Where multiple repeaters are installed in a county, one should be on the 8CALL90 frequency. This channel should be monitored by a public safety dispatch center.
 
The Local Government licensed shared public safety Mutual Aid Conventional 800MHz radio repeaters should utilize one of the five National Public Safety Tactical 800MHz frequencies or South Carolina Tactical frequencies.
 
Frequencies shall be assigned so as to prevent or reduce co-channel interference.
 
Where possible, the State and Local Government repeaters should not be co-located.
 
The shared public safety Mutual Aid Conventional 800MHz radio repeaters shall have an output power of at least 100 watts.
 
All shared public safety conventional 800 MHz radio repeaters shall use a CCTSS tone of 156.7 Hz for decode and encode. A second tone may be utilized for local communications. The second tone should be coordinated with the state frequency coordinator.
 
The Calling Channel shall not use any means of encryption or other selective signaling techniques.
 
Where possible, the shared public safety conventional 800 MHz radio repeaters should be operated from a DC Power system equipped with a backup system and/or emergency generator backup for power failures.
 
Where the State or Local Government has available antenna space, antenna systems, building space or power, this may be made available to the other through a shared use agreement.
 
Where the State or Local Government has available 800 MHz conventional radio repeaters that use channels other than the Mutual Aid Channels listed, they may be made available through a shared use agreement.
 
The licensee of a public safety conventional 800 MHz Non-Mutual Aid Channel radio repeater, as listed in item 15, is responsible for monitoring and controlling the use of that repeater.
 
The conventional Mutual Aid repeaters shall not be used for routine daily operations or as ongoing working channels by any agency. These channels shall be reserved for inter-agency communications, incidents requiring multi-agency participation and emergencies. These shall not be used for administrative or intra-agency communications unless so directed during a major emergency or disaster situation.
 
Examples of Proper Use of Mutual Aid Channels:
  • As working channels for multiple fire departments fighting a fire together.
  • For coordination during a police chase through multiple jurisdictions where the agencies have no other communications link with each other.
  • For communications during extended joint operations between multiple police agencies such as drug operations, riots, etc.
  • For coordination during recovery operations after a disaster such as a hurricane or earthquake when local, state, and federal offices require a common communication link.
Examples of Improper Use of Mutual Aid Channels:
  • To support the administrative functions of a fire department which has a mutual aid agreement with an adjacent fire department to provide “move up” capability when a fire unit leaves its own coverage area.
  • To provide an extra working channel for a public safety agency supporting a special event.
  • To provide a surveillance channel for use between members of the same public safety agency.       
A Public Safety Dispatch Center or Communications Agency in the geographic coverage area of each system (normally the County Sheriff’s Office or County Communications Center) is designated by the South Carolina Region 37 Committee and the 800 MHz Advisory Committee to:
  • Have direct control of the Mutual Aid Channels mobile relay station(s).
  • Provide 24 hours/day, 7 days/week monitoring of the Mutual Aid Channel(s).
  • Assign the use of Mutual Aid TAC channels upon request on a per incident basis.
  • Coordinate the most effective and efficient assignment and use of Mutual Aid Channel(s). During emergency or disaster situations, the State of South Carolina may assume control over one or more Mutual Aid Channels.
All scheduled special event use of a shared 800MHz conventional repeater(s) is limited to the 8SCTAC frequencies ONLY. Special event use should be coordinated with the agency providing direct control of the Mutual Aid channel. Use of the channel shall not interfere with emergency or disaster situations. If an emergency or disaster situation develops the agency providing direct control of the of the Mutual Aid channel(s) under its authority may terminate the Special Event Use of the Mutual Aid channel.
 
During a period of high traffic, communications on a shared 800MHz conventional repeater should be essential and brief.
 
Inter-agency communications should utilize the agency name and radio call sign.
 
Fixed Base, Mobile Relay and RF Control Stations must be FCC type-accepted for use in the 806-809/851-854 MHz band and must additionally have at least 20 dB selectivity at 12.5 KHz offset.
 
Mobile and portable radios operating on these channels are not required to meet the requirements in 22 above.
 
All mobile and portable equipment operating in the 806-808 MHz band shall be equipped to operate on all ten (10) of the Mutual Aid Channels
 
Plain ENGLISH will be used at all times on all Mutual Aid Channels. The use of unfamiliar terms, codes or signals in not allowed.
 
The use of ric switches or console cross-patching is not allowed on any of the Mutual Aid Channels .
 
Telephone interconnect (i.e.. telephone patching) is prohibited on any of the Mutual Aid Channels.