Operating Modes and Protocols

Operating Modes and Protocols: ( Those most likely to be employed in bold type )

a)  SPEECH

The message handling protocol to be used on team nets is the RAYNET Voice Procedure. This is compatible with the IARU HF Emergency Operating procedure and is suitable for UK and international use.

b)  DATA

There are a wide variety of data modes in use in the Amateur Service, each meeting the needs of a particular user group or set of propagation conditions. To allow flexibility RSID ( Reed Solomon Identification ) is used by many programs to identify which mode is in use and some client software monitors the signal to noise levels of transmissions to allow automatic mode changing to reflect the current conditions.

With flexibility comes complexity, the video below lasts around 20 minutes and is a walkthrough of one particular software suite and the configuration settings required. The specific modes to be tested on a particular net would be announced via the mailing list.

The message handling protocol to be used on team nets where the Flmsg package is not in use is the RAYNET Data Procedure. This is compatible with the IARU HF Emergency Operating procedure and is suitable for UK and international use.

c) CW

CW remains a good emergency communications mode able to use simple equipment and is very power efficient. Operator skill is still required though, especially for weak signal working.

The message handling protocol to be used on team nets is the RAYNET CW Procedure. This is broadly compatible with the IARU HF Emergency Operating procedure and is suitable for UK and international use.

d)  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).

e)  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.

APRS is capable of handling formal messaging using the procedure specified in the RAYNET Data Procedure. This is compatible with the APRS Protocol reference and is suitable for UK and international use.

f) 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.

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