Aegis Operation; Voice Modes; Mode 1: Clear Modes; Mode 2: Aegis Digital Mode - Ericsson EDACS PRISM HP Operator's Manual

VOICE MODES

Aegis programmed systems have three (3) different
voice modes: clear (analog), digital and private (en-
crypted). The voice modes are programmed on a per-
group basis within each trunked system and on a per-
channel basis within each conventional system.

Mode 1: Clear Modes

The Aegis clear mode is a voice mode in which the
radio transmits and receives only clear (analog) voice
signals. These analog signals are non-digitized and non-
encrypted. Clear mode transmissions can be easily
monitored by unauthorized persons. Groups or channels
programmed for clear operation cannot transmit or re-
ceive Aegis digital or private messages.

Mode 2: Aegis Digital Mode

The Aegis digital mode allows the radio to transmit
and receive digitized voice signals. Aegis digital signals
provide improved weak signal performance and cannot
be easily monitored with a standard receiver. Groups and
channels programmed for Aegis digital operation trans-
mit only digital signals. Private (encrypted) calls cannot
be received or transmitted when the radio is in the Aegis
digital mode because the radio does not know the cryp-
tographic key used. Message trunked group calls and
individual calls are answered back in the mode which
they are were received assuming the call or hang time is
still active. Individual phone, all, and emergency calls are

AEGIS OPERATION

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