JP 3-50 National Search and Rescue Manual Vol I - US Navy

9. SART.
10. MF DSC, used to initiate ship-to-ship call or ship-to-shore
call when within 100 NM of shore. Call can be initiated
without anyone listening to radio.
11. HF DSC, same purpose as MF DSC, except provides worldwide
coverage
D. Alerting signals in GMDSS include the frequencies listed below.
Shore facilities providing these future services are scheduled to have
24-hour guards and direct connection to the area RCC.
1. Satellite EPIRB signals, 406.025 MHz, and 1.6 GHz.
2. Satellite Ship Earth Station signals, 1.6 GHz band.
3. Digital Selective Calling, 2, 4, 6, 8, 12, and 17 MHz (FM)
band.
4. Navigation, Meteorological, and Urgent information broadcasts
shore-to-ship on 518 kHz, using NBDP telegraph equipment
(NAVTEX).
320 COMMUNICATION FACILITIES
A. Voice Communications provide the most rapid means of
transmitting urgent information, and usually are the most practical for
directing on scene operations. They may be accomplished by using:
1. Telephone Private Lines (TPL). When established specifically
for SAR nets, they may be called SARTELs. ARTCCs have
widespread voice circuits for domestic and international
traffic control. These can be extremely valuable for SAR,
particularly in aircraft incidents. Urgent communications
between two RCCs can often be relayed by an ARTCC.
2. Automatic Voice Network (AUTOVON), a worldwide direct-dial
system of voice communications for United States military
agencies.
3. Federal Telephone System (FTS), a direct-dial system within
the United States for use by United States government
agencies.
4. Commercial telephone, the most widespread method of domestic
and international voice communications. It often provides the
most rapid means of transmitting or obtaining information.
5. Radiotelephone, the most common type of radio communications
among surface, air, and fixed stations. There are innumerable
uses of radiotelephone circuits and a considerable number of
networks that can be used in SAR operations. Radiotelephone