Chicago Police DepartmentSpecial Order S03-01-01
Radio Communications
Issue Date:01 August 1997Effective Date:02 August 1997
Index Category:Field Operations
This directive provides an overview of the radio communications system. Department members will refer to the General order titled "Radio Communications" for radio communication field operating procedures.
II.Radio Communications System
The Department's Radio Communications System consists of:
  • A.thirteen (13) zone channels for district patrol use.
  • (7) City-wide channels.
  • C.a seven channel, 800 MHZ trunked radio system for specialized uses.
  • D.a Point-to-Point radio network for communications with other police agencies.
  • Illinois State Police Emergency Radio Network (ISPERN) for emergency communications with other agencies.
  • F.a 31-channel, 800 MHZ Data Radio Network for mobile data terminal (MDT) and portable data terminal (PDT) operations.
III.System Overview
  • A.Each radio has multiple channels: the primary channel, over which the unit receives assignments and normally operates; and the alternate channels.
  • B.The alternate emergency channels (City-wide 3, 5, and 6) may be used when:
    • 1.directing emergency plans.
    • 2.communicating with units assigned to a different primary channel.
    • 3.transmitting descriptions and messages if radio traffic is heavy on the primary channel.
    • 4.technical difficulties interfere with transmission on the primary channel.
    • 5.requesting support such as:
      • "R" service.
      • b.reporting "open key" situations.
      • c.notifying the Office of Emergency Management and Communications (OEMC) of a "zone malfunction."
  • C.Mobile Relay - allows units to hear other units talk on the same channel. Communication between units will be initiated by contacting the dispatcher. Units on different channels may communicate with each other by switching to a common channel, after obtaining authorization from the dispatcher.
  • D.Simulcast - is a method of dispatch that enables a dispatcher to broadcast emergency messages on selected channels simultaneously.
  • E.All Call Broadcast - is a method of dispatch that enables the Point-to-Point console dispatcher to broadcast messages on all channels simultaneously.
IV.Radio Call Numbers
  • A.Radio dispatching for all personnel is accomplished by use of radio call numbers.
  • B.All personnel operating a radio equipped unit, except those who have permanent radio call identification numbers assigned, will receive their radio call identification numbers at the beginning of their tour of duty.
  • C.A staff member will use:
    • alphabetical suffix to the unit commanding officer's radio call identification number, e.g., "700B" (7th District Commander's staff).
    • 2.a numerical suffix to the unit commanding officer's radio call identification number when that call number already has an assigned alphabetical suffix, e.g., "3D" (Director of News Affair's staff).
Matt L. Rodriguez
Superintendent of Police
95-081 BJD/PS