Communications via 2-way radio
June 1, 2007
“Can you believe the hat she was wearing?”
“Negative. The last time I saw anything like that it was being chased by a cat.”
The above 2-way radio transmissions were the first such comments overheard during what would have (should have) been a regular day; a day made all the more interesting because additional comments were overheard by the woman who was wearing the hat.
As interest grew in “The Hat,” additional personnel began to ask about it, thus further descriptions made it possible for the woman to overhear subsequent radio transmissions received by personnel quite distant from the original contact with “The Hat,” and impossible for her to ignore because subsequent comments branched off into the remainder of her ensemble.
Needless to say this caused some very unnecessary embarrassment to the innocent passenger, and attention to organization management for the lack of control of the employee population where radio communications were concerned. But not unlike far too many corrective actions taken by management teams, something has to “go south” before action is taken.
Our basic philosophy is L.E.S.S. is more by confining transmissions to: Location, Extension, Situation, Status.
What follows are some simple yet important considerations that should be made part of any organizations’ 2-way radio communications requirements.
1 â€” Call signs
Use of personal names over the radio should be avoided whenever possible.
Call signs function as on-air names, thereby helping to avoid the confusion that can arise when two or more employees have the same (or similar-sounding) names (we also use call signs in reports instead of having to write out the employees’ names). Additionally, these call signs allow for anonymity when out amidst the general public rather than drawing attention to the workers.
2 â€” Assigning call signs
Most of our call signs consist of a three-digit number. Managers are given a four-digit call sign with the first two digits always being 15 (spoken as “fifteen”), and the third digit designating the manager’s department. (Ex: 1521, spoken as “fifteen-two-one,” designates the safety manager. The following numerical sequences are used in assigning call signs:
200 Safety & Facilities Maintenance
400 Maintenance; Electronics (420 – 439) & Electromechanical (440 – 459)
500 Maintenance; Stores, Maintenance Control, Vehicles (540 – 570)
600 Systems/Software Support & Document Control
900 Senior Management
Supervisory personnel are assigned three-digit call signs ending in a zero. The first and second digits represent the employee’s department and section (Ex: 440. Spoken as “four-four-zero,” designates a supervisor in maintenance, specifically the electromechanical department).
3 â€” Operating the radio
• Listen to make sure the channel is open before attempting to transmit.
• Press and hold the PUSH-TO-TALK button for one full second before speaking (this avoids losing the beginning portions of communications).
• Speak in a normal voice, holding the radio to the side of your mouth, about 3 to 5 inches away. Holding the radio too close to your mouth will make it difficult for others to understand your transmission.
• Allow enough time for the intended receiver to respond before repeating a call. (It takes a second or two for the radio to switch from TRANSMIT to RECEIVE, so allow a little time after the speaker finishes talking before giving your reply.)
• Keep your message concise and to the point; do not use the radio for personal conversations.
• Never transmit any false information or use obscene language on the radios.
• Indicate the end of a transmission by saying the word OUT. This lets others know that the radio frequency is
•If you want to end one conversation and immediately begin talking with another party, you must use the word BREAK.
4 â€” Radio protocol
Initiating/Responding to a Call
First we identify the person we want/need to communicate with, followed by our own call sign:
461 (person being called)
247 (person initiating the call)
The receiver then responds by stating his/her call sign and location:
Example: This is 461 at Station 3.
5 â€” Words & phrases
In everyday speech, certain words and phrases have more than one meaning. Because lives may depend on communicating a complex message quickly and clearly, special words and phrases are used on the radio system. Some of the special words we use include:
Acknowledge: Tell me if you have received and understood my message.
Affirmative: “Yes” or “That is correct.”
Break: Indicates that a person is ending a conversation with one party and immediately initiating a conversation with another during the same transmission.
Central: Radio Base Station.
Confirm: Indicates that the previous information/message must be clarified â€” there is a possible misunderstanding or on- scene verification must be made (e.g. switch position).
Copy: I have received and understood your message.
Gulliver: Used by an employee who requires immediate police assistance and is unable to speak freely for fear of physical harm. Must be used only in emergency situations to secure an employee’s personal safety. Be sure to indicate location where police are needed. This should be worked into a normal sentence, if possible, if you want to avoid tipping off any listener. For example: “This is Gulliver at Station 3.”
Negative: “No,” “permission not granted,” “that is not correct,” or “I do not agree.”
Over: Indicates that the conversation is to continue and a reply is expected.
Out: Indicates that the conversation is ended and no reply is expected.
Priority Call: Do not transmit. All other radio communications must stop while Central handles a priority call.
Proceed: You may continue with the action for which you just requested permission.
Repeat: Please repeat last transmission.
Roger: I have received and understood your message.
Roger Wilco: I have received and understood your message and will comply with your instructions.
Say Again: Please repeat the last transmission.
Stand By: Please wait and continue to monitor the radio.
Understood: I have heard and understand your message.
Verify: Confirm the following information.
6 â€” Conveying time
Time is communicated using the 24-hour clock (military system) because we operate 24 hours a day (this helps to avoid confusion over AM or PM), as midnight is 0000 or “zero hours,” noon is 1200 or “twelve hundred hours,” nine o’clock in the morning is “zero nine hundred hours,” and nine in the evening is “twenty-one hundred hours.”
7 â€” Letters & numbers
Reference to letters are made using the standard phonetic alphabet:
Multiple digit numbers are pronounced digit-by-digit (avoiding the use of the word “oh” for numbers containing a zero); decimals are expressed by the word “point.”
For example: Vehicle 15 = one-five, Block 2113 = two-one-one-three, Switch 15-1 = one-five dash one, 75.4 = seven-five-point-four
Note: We do not use the digit-by-digit pronunciation when referring to time or four-digit call signs.
Overall, our radio communications have evolved and matured over the last 15 years. Any suggestions?