Radiogram (message)

For other uses, see Radiogram.

A radiogram is a formal written message transmitted by radio. Also known as a radio telegram or radio telegraphic message, radiograms use a standardized message format, form and radiotelephone and/or radiotelegraph transmission procedures. These procedures typically provide a means of transmitting the content of the messages without including the names of the various headers and message sections, so as to minimize the time needed to transmit messages over limited and/or congested radio channels. Various formats have been used historically by maritime radio services, military organizations, and Amateur Radio organizations.

Radiograms are typically employed for conducting Record communications, which provides a message transmission and delivery audit trail. Sometimes these records are kept for proprietary purposes internal to the organization sending them, but are also sometimes legally defined as public records. For example, maritime Mayday/SOS messages transmitted by radio are defined by international agreements as public records.

Historical development

The concept of the standard message format originated in the wired telegraph services. Each telegraph company likely had its own format, but soon after radio telegraph services began, some elements of the message exchange format were codified in international conventions (such as the International Radiotelegraph Convention, Washington, 1927), and these were then often duplicated in domestic radio communications regulations (such as the FCC in the U.S.) and in military procedure documentation.

Military organizations independently developed their own procedures, and in addition to differing from the international procedures, they sometimes differed between different branches of the military within the same country.

For example, the publication "Communication Instructions, 1929", from the U.S. Navy Department, includes:

Notable characteristics of radiograms include headers that include information such as the from and to addresses, date and time filed, and precedence (e.g. emergency, priority, or routine), so that the radio operators can determine which messages need to be delivered first during times of congestion.

Chronology of the commercial radiogram format

Maritime radio service radiotelegrams

The message format for communications transmitted to sea-going vessels is defined in Rec. ITU-R M.1171, § 28:[3]

  1. radiotelegram begins: from . . . (name of ship or aircraft);
  2. number . . . (serial number of radiotelegram);
  3. number of words . . . ;
  4. date . . . ;
  5. time . . . (time radiotelegram was handed in aboard ship or aircraft);
  6. service indicators (if any);
  7. address . . . ;
  8. text . . . ;
  9. signature . . . (if any);
  10. radiotelegram ends, over

Airline Teletype Message

The international airline industry continues to use a radioteletype message format originally designed for transmission to Teleprinters, Airline Teletype System, which is now disseminated via e-mail and other modern electronic formats. However, the relationship of the IATA Type B message to other radio telegram message formats is clearly visible in a typical message:

QD AAABBCC
.XXXYYZZ 111301
ASM
UTC
27SEP03899E001/TSTF DL Y
NEW
BA667/13APR
J 319 C1M25VVA4C26
LHR1340 BCN1610
LHRQQQ 99/1
QQQBCN 98/A
QQQQQQ 906/PAYDIV B
LHRQQQ 999/1
QQQBCN 998/A
SI

Military radiograms

Military organizations have historically used radiograms for transmitting messages. One notable example is the notification of the air raid on Pearl Harbor[4] that brought the United States into World War II.

The standard military radiogram format (in NATO allied nations) is known as the 16-line message format, for the manner in which a paper message form is transcribed through voice, Morse code, or TTY transmission formats. Each format line contains pre-defined content.

When sent as an ACP-126 message over teletype, a 16-line format radiogram would appear similar to this:

RFHT
DE RFG NR 114
R 151412Z MAR
FM CG FIFTH CORPS
TO CG THIRD INFDIV
WD GRNC
BT
UNCLAS
PLAINDRESS SINGLE ADDRESS
MESSAGES WILL BE TRANSMITTED
OVER TELETIPEWRITER CIRCUITS
AS INDICATED IN THIS EXAMPLE
BT
C WA OVER TELETYPEWRITER
NNNN

Some of the format lines in the above example have been omitted for efficiency. The translation of this abbreviate format follows:

Format Line Message Text Explanation
Line 2 RFHT Station being called, which will receive the message
Line 3 DE RFG NR 114 Sent by radio station having the callsign RFG, station serial number 114
Line 5 R 151412Z MAR Routine precedence, March 15, 2:12pm UTC in Date-time group format
Line 6 FM CG FIFTH CORPS The message is from CG FIFTH CORPS
Line 7 TO CG THIRD INFDIV The message is to CG THIRD INFDIV
Line 10 WD GRNC Accounting symbol (WD); word groups have not been counted (GRNC)
Line 11 BT Section separator between heading and text
Line 12 UNCLAS

PLAINDRESS SINGLE ADDRESS

MESSAGES WILL BE TRANSMITTED

OVER TELETYPEWRITER CIRCUITS

AS INDICATED IN THIS EXAMPLE

 Message content is unclassified, and the message is...
Line 13 BT Section separator between text and the ending
Line 15 C WA OVER TELETYPEWRITER corrects (C) word after (WA) "OVER" to "TELETYPEWRITER"
Line 16 NNNN end-of-message indicator

This radiotelegraph message format (also "radio teletype message format", "teletypewriter message format", and "radiotelephone message format") and transmission procedures have been documented in numerous military standards, including the World War II-era U.S. Army Manuals TM 11-454 (The Radio Operator), FM 24-5 (Basic Field Manual, Signal Communication),[5] FM 24-6 (Radio Operator's Manual),[6] TM 1-460 (Radiotelephone Procedure), FM 24-18 (Radio Communication), FM-24-19 (Radio Operator's Handbook), FM 101-5-2 (U.S. Army Report and Message Formats), TM 11-380, FM 11-490-7 (Military Affiliate Radio System), AR 105-75, Navy Department Communication Instructions 1929,[7] and their modern decedents in the Allied Communications Procedures, including ACP 124 (messages relayed by telegraphy), ACP 125 (messages relayed by voice), ACP 126 (messages relayed by radio teletype), ACP 127 (messages relayed by automated tape), AR 25-6, U.S. Navy Signalman training courses[8][9] and others.

At one point before World War II, the U.S. FCC defined (at least for domestic police radio traffic) a station serial number as a sequential message number that was reset at the beginning of each calendar month.[10]

The Communications Standard Dictionary defines radiotelegraph message format as "The prescribed arrangement of the parts of a message that has been prepared for radiotelegraph transmission."[11]

This example of an USMTF message contains a good summary of the message creation and handling rules.

MARS radiograms

The Military Affiliate Radio System uses radiograms, or MARSgrams,[12] to transmit health & welfare message between military members and their families, and also for emergency communications. Some MARS radio procedure documents include instructions on how to exchange ARRL NTS Radiograms over a MARS radio net. Both formats include a procedure for counting the number of word groups (words in NTS, groups in the ACP/MARS format), but differ in how word groups are counted, for instance, so the counting method must be resolved when converting messages between formats.

U.S. Department of State ACP-127 radiograms

The U.S. Department of State uses the military's automated message delivery version of the 16-line format, known as ACP-127, with its own structured definitions of the format lines.[13]

Police Radiogram

Police radiograms had their own format, likely derived from the commercial radiogram format.

Example radiogram from A National Training Manual and Procedural Guide for Police and Public Safety Radio Communications Personnel, 1968.[14]

15 SHRF LEE COUNTY ILL 12-20-66 (A. Preamble)
PD CARBONDALE ILL (B. Address)
DATA AND DISPOSITION RED 62 CHEVROLET (C. Text)
4 DOOR ILL LL1948 VIN 21723T58723
ABANDONED DIXON ILLINOIS THREE DAYS
HELD ANDREWS GARAGE FRONT END DAMAGED
NOT DRIVEABLE NO APPREHENSIONS WILL
BE RELEASED TO OWNER ON PROOF OF
OWNERSHIP
SHERIFF LEE COUNTY
ILLINOIS JRM 1530 CST (D. Signature)

Section A6.6 Message Form

From the above training manual:

A formal message is one constructed, transmitted and recorded according to a standard prescribed form (see Sec. 4). A formal message should contain the following essential P A R T S:

  1. Preamble - message number, point of origin or agency identifier, date.
  2. Address - to whom the message is directed.
  3. Reference - to previous message, if any.
  4. Text - the message.
  5. Signature or Authority - department requesting the message.

ARRL radiogram

Main article: ARRL Radiogram
historic ARRL radiogram form

An ARRL radiogram is an instance of formal written message traffic routed by a network of amateur radio operators through traffic nets, called the National Traffic System (NTS).

It is a plaintext message, along with relevant metadata (headers), that is placed into a traffic net by an amateur radio operator. Each radiogram is relayed, possibly through one or more other amateur radio operators, to a radio operator who volunteers to deliver the radiogram content to its destination.

VOA Radiogram

VOA Radiogram is an experimental Voice of America program, started in 2012, which broadcasts digital text and images via shortwave radiograms [15] This digital stream can be decoded using a basic AM shortwave receiver and freely downloadable software of the Fldigi family. This software is available for Windows, Apple (OSX), Linux, and FreeBSD systems.

The mode used most often on VOA Radiogram, for both text and images, is MFSK32, but other modes are occasionally transmitted.

VOA Radiogram Broadcast Schedule[16]
Day and Time (UTC) Shortwave Frequency (kHz)
Saturday 0930 - 1000 7545
Saturday 1600 - 1630 17870
Sunday 0230 - 0300 5745
Sunday 1930 - 2000 15670

References

  1. ↑ "International Telegraph Conference (London, 1903)" (PDF). Retrieved 26 April 2015.
  2. ↑ "International Telegraph Conference (Paris, 1925)" (PDF). Retrieved 26 April 2015.
  3. ↑ "Rec. ITU-R M.1171" (PDF).
  4. ↑ "Radiogram reporting the Pearl Harbor attack, December 7, 1941".
  5. ↑ "FM 24-5 (Basic Field Manual, Signal Communication)" (PDF).
  6. ↑ "FM 24-6 (Radio Operator's Manual)" (PDF).
  7. ↑ "FM 11-490-7 (Military Affiliate Radio System)" (PDF).
  8. ↑ "U.S. Navy Signalman training course" (PDF).
  9. ↑ "U.S. Navy Signalman training course" (PDF).
  10. ↑ "The APCO Bulletin, 1938" (PDF).
  11. ↑ "Communications Standard Dictionary". Retrieved 19 April 2015.
  12. ↑ "MARS Radiogram" (PDF).
  13. ↑ "5 FAH-2 H-320 ACP-127 FORMAT LINES".
  14. ↑ "A National Training Manual and Procedural Guide for Police and Public Safety Radio Communications Personnel". Retrieved 27 April 2015.
  15. ↑ "VOA Radiogram". VOA Radiogram. Retrieved 2014-04-15.
  16. ↑ http://voaradiogram.net/
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