3-07/010.30 - Radio Channel Usage

The Department's radio system operates under the command and control of the Communication and Fleet Management Bureau (CFMB).  Users must follow Department operating procedures and FCC rules.

Department radio channels are a shared resource.  Any unit may request that a non-dispatch channel be temporarily restricted for its use as the situation warrants.  Most channels are available only in specific geographical areas; therefore, their assignment must be closely coordinated to ensure effective use.  The Sheriff’s Communication Center (SCC) watch commander may restrict or alter channel assignments based upon type of operation, other concurrent operations, area of required coverage, and priority.

The following information describes general channel usage:

Dispatch Channels:  Stations are assigned to specific dispatch channels.  These channels will be used for dispatching and communicating with station units.  Dispatch channels shall be used only in the "repeat mode."

Local Tactical (L-TAC) Channels:  Stations are assigned to specific local tactical channels.  L-TAC channels will be used for tactical coordination within a station area. Should the need for an additional tactical channel arise, one may be requested through the SCC watch commander.

Area Tactical (A-TAC) Channels:  Tactical/special operation channels which provide wide geographic area coverage.  Use of these channels are restricted and requires concurrence from the SCC watch commander prior to their use.

Countywide Tactical (C-TAC) Channels:  There is one tactical/special operation channels (C-Tac-1) which provides countywide coverage. Use of this channels is restricted and requires concurrence from the SCC watch commander prior to its use.

RTC-Mutual Aid (MA) Channels:  Provide a radio communications link to participating outside agencies.  These channels are restricted and may be used only with the prior approval of the SCC watch commander.

Custody Channels (13 Repeat/Direct Channels):  Reserved for use by custody divisions.

Court Services Channels (Four Repeat and four Simplex Channels):  Reserved for use by Court Services Division.

Countywide SCC Access Channel:  Provides access to SCC for database inquiries and relaying of information.  The SCC Access channel is also the home dispatch channel to Transportation Bureau, District Attorney investigators, County Services Bureau, Parks Bureau, Court Services Division units, and the Parole Compliance Bureau.

Countywide Simplex (SIMPLEX 1):  Unrestricted Simplex channel for unit-to-unit short range communication.

Emergency Channel:  Countywide channel restricted solely to request emergency assistance.

Special Unit Dispatch (SUD) Channel:  Countywide channel for use by units that are not dispatched through SCC.

Star Tac (S-Tac) Channels:  Used by assigned Department investigative and special operations units.  The available channels are: S-Tac 2R, 3R, 4R, 9R, 14R, and 19R.  These channels are restricted and may be used only with the prior approval of the SCC watch commander.

Portable Repeater Channels:  Reserved for special events and operations.  These channels will only function when used with a portable repeater and shall not be used without prior approval of the SCC watch commander.  The channels available are: Port Rpt (PR-3) in service as well as SPL Rpt 1 and 2.

The following list describes the channel plan for the Department.  Channels marked with an asterisk (*) are monitored on a full-time basis by SCC.

480 MHZ Voice Radio System

                                               
470 MHZ        DIGITAL RADIO SYSTEM