BASIC RADIOTELEPHONE MESSAGE FORMAT

Radiotelephone uses a 16-line message format (table 2-4) that is comparable to formats in teleprinter communications. Radiotelephone messages also have the same three military message forms: plaindress, abbreviated plaindress, and codress.

By far, the most common message form in R/T traffic is the abbreviated plaindress. In fact, the abbreviated plaindress message is sometimes so abbreviated that it closely resembles the basic message format. The three major message parts-heading, text, and ending-are there, however. Each of these major parts is reduced to components and elements.

All format lines do not necessarily appear in every message. When a line is used, it must be placed in the message in the order shown in table 2-4. An abbreviated plaindress message may omit any or all of the following: precedence, date, date-time group (DTG), and/or group count. A codress message is one in which the entire address is encrypted within the text. The heading of a codress message contains only information necessary to enable communications personnel to handle it properly.

Notice that prowords, not prosigns, are used in voice communications. Because prowords are spoken, it is important that you, as the operator, be completely familiar with them. Refer to table 2-2 for a list of many of the commonly used prowords, their explanations, and their equivalent prosigns. Throughout this chapter, prowords are shown in all capital letters.

Table 2-4.-Radiotelephone Message Format

In the following paragraphs, we will discuss the format lines used in the R/T message format. Refer to table 2-4.

FORMAT LINES 1, 2, 3, AND 4

Format line 1 is not used in R/T procedures. Format lines 2 and 3 contain the call sign, the proword MESSAGE, and the transmission identification.

The call may take one of the following forms:

Full Call

"Kamehameha (station called),

THIS IS

Vallejo" (station calling)

Abbreviated Call

"THIS IS

Vallejo" (station calling).

Normally, a full call is used when first establishing a net and when reporting into a previously established net. A full call is also used in the transmission instructions and address components when a message is required to be relayed to a station on a different net.

Once communications are established and no confusion will result, an abbreviated call may be used. To further expedite voice communications, the receiving station may omit the proword THIS IS when the station is responding to a call and communications are good. Additionally, the call may be omitted entirely when two stations are in continuous communication or the net is not shared by a third station.

When a collective call sign is used and some of the addressees are to be exempted, you do so in the call by using the proword EXEMPT, followed by the call sign(s) of the station(s) exempted. For example:

"Edison (collective call)

EXEMPT

Tecumseh (station exempted),

THIS IS

Vallejo" (station calling).

Notice that only one station is exempted in this call-up. If there had been more than one station, each station would have been spoken before the proword THIS IS.

After the call, transmit the proword MESSAGE if you wish to indicate that a message you are about to transmit requires recording. For example:

"Vallejo (station called),

THIS IS

Kamehameha (station calling)

MESSAGE" (message is to follow).

The transmission identification is normally a station serial number used mostly in teleprinter procedures. When used in voice communications, the transmission identification is the last element of format lines 2 and 3, consisting of the station serial number preceded by the proword NUMBER.

Format line 4 contains the transmission instructions, which may consist of the prowords RELAY TO, WORDS TWICE, DO NOT ANSWER, or READ BACK. The use of these prowords is explained later.

FORMAT LINE 5

Format line 5 contains the precedence, DTG, and any necessary message instructions. The precedence is the first element of format line 5. In the case of a dual-precedence message, the higher precedence is transmitted first; for example, "PRIORITY ROUTINE." The DTG is preceded by the proword TIME. An example of this format line is as follows:

"Vallejo, THIS IS Polk, RELAY TO Key, PRIORITY, TIME, Tree Zero Wun Fower Fower Fife Zulu."

Message instructions are not normally required in R/T messages. When included, they consist of short and concise instructions that indicate the status of the message. Message instructions remain with the message until the message reaches its destined station. For example, if the message is a suspected duplicate, the phrase "This Message Is A Suspected Duplicate" immediately follows the DTG.

FORMAT LINES 6, 7, 8, AND 9

Format lines 6, 7, 8, and 9 form the address of the message and are recognized by the prowords FROM, TO, INFO, and EXEMPT, respectively. When the originator and the addressee are in direct communication, the call may serve as the address. Table 2-5 is an example of an R/T transmission showing elements of the heading components (format lines 2 through 9).

Table 2-5.-R/T Message Showing All Possible Elements of the Address Components.

FORMAT LINE 10

Format line 10 is identified by the proword GROUPS, followed by the number of groups, or "GROUP NO COUNT." This line may contain an accounting symbol in addition to the group designation. Accounting symbols are seldom used on R/T circuits. However, they may appear on messages received for relay from circuits using other procedures. Accounting symbols are a combination of letters used to indicate the agency, service, or activity that assumes financial responsibility for the message.

Since R/T messages are usually short, a group count is seldom used. However, if a group count is sent, the number of groups is preceded by the proword GROUPS and appears in the message prefix. When a message is transmitted before the group count is determined, the proword GROUP NO COUNT is used in lieu of the group count. The actual group count may then be transmitted in the final instructions and be inserted in the message prefix by the receiving operator. The proword GROUP NO COUNT is included in messages bearing an accounting symbol when groups are not counted.

FORMAT LINES 11 THROUGH 16

Format line 11 contains the proword BREAK. This line separates the heading from the text. The use of this proword is not required except where confusion may be possible between the heading and text.

Format line 12 is the text of the message and expresses the idea of the originator. The primary difference between R/T text and other types of communication is that R/T text must be spoken. Therefore, it is important that new operators thoroughly familiarize themselves with the proper phrases and prowords that are commonly used in communications texts.

Format line 13 contains the proword BREAK. This line separates the text from the ending. Like format line 11, this proword should be used when confusion may occur between the text and the ending.

Format line 14 is used only in abbreviated plaindress messages when a time group is transmitted here. When used, it takes the place of a DTG in format line 5. For example, a DTG may not be determined prior to transmission. In such cases, it may be omitted in format line 5 and be sent as a time group in format line 14. When used, format line 14 consists of the proword TIME, followed by the time group plus the zone suffix. For example, you are in time zone B and you are sending a time group of 310850 in format line 14. You would transmit the time group as:

"TIME Three One Zero Eight Five Zero Bravo."

Format line 15 contains any final instructions. When used, this line may contain prowords (such as WAIT, CORRECTION, MORE TO FOLLOW, AUTHENTICATION IS), operating signals, address groups, call signs, and plain language designators.

Format line 16 is identified by the proword OVER or OUT. Every transmission ends with either OVER or OUT. However, the proword OVER may be omitted when two stations are in continuous communication with each other on a circuit not shared with a third station. In transmissions where the proword DO NOT ANSWER is used, the transmissions must end with the Proword OUT.