Operating Modes and Protocols: ( Those most likely to be employed in bold type )
a) SPEECH
b) DATA :- PSK31 /MFSK16 & Pactor I & Amtor & RTTY & CW
Other datamodes include Pactor II, Clover II, G-Tor and an increasing number of PSK and MFSK variants. Whilst not ruling out any of these for emergency datacomms, it should be borne in mind that one always has to consider what modes or protocols the majority of stations are normally set-up to use – probably PSK31/MFSK16, PACTOR I, AMTOR & RTTY!
Obviously new datamodes are still in constant development and the situation needs to be kept under continuous review
c) VISUAL : SSTV and Fax
SSTV standards vary, depending which side of the Atlantic or which band you are on, but well known ones are Martin (UK), Scottie (US) and Robot 36 modes.
FAX transmissions generally follow the main Weatherfax standards (which are usually available in the decoding software – often bundled in with SSTV software).
d) APRS:
APRS*/UiView*:The most popular use of APRS (Automatic Packet Reporting System) and its UK compliment, UiView, would appear to be for people/vehicle location by passing and interpreting information received from GPS receivers over the air by the TNC in a packet radio format and through suitable software, displayed moving along a map, via constant data updates over the radio. What must not be forgotten however, is that the APRS programme additionally provides for short text bulletins, ancilliary equipment (such as electronic home weather station data) and frequency coordination purposes.
e) EXPERIMENTAL : ALE, Digital Speech etc.
ALE is Automatic Link Establishment, where automatic ‘soundings’ and received analysis of these signals on a set of frequencies allows the optimum frequency for good contact to be established. It is claimed that this has a higher success rate than manual selection and its use is rapidly increasing in commercial HF.
There is an ALE programme that Amateurs can use written by Charles Brain, G4GUO, and can be found on the website of N2CKH.