40 System Feature Overview
April 2011 68007024085
2.3.4.4 Emergency Voice Interrupt for Emergency Alarm
The Emergency Voice Interrupt feature, when enabled in a radio, is used during the initiation of an
emergency condition when an interruptible voice transmission is already taking place on the
channel.
When an emergency is initiated with Emergency Voice Interrupt enabled, the radio attempts to
interrupt an ongoing, interruptible voice transmission on the channel. The radio then uses the
established procedures for either Emergency Alarm or Emergency Alarm with Call, depending
upon the CPS configuration. For the Emergency Voice Interrupt for Emergency Alarm feature, the
radio is not required to be a member of the voice call being interrupted.
NOTE: For the Emergency Voice Interrupt for Emergency Alarm feature to operate consistently,
all radios using the channel should be provisioned with the ability to be interrupted.
However, not all need to be provisioned with the Emergency Voice Interrupt for Emergency
Alarm capability.
If some radios are provisioned without the ability to be interrupted (e.g., normally desirable for a
supervisor’s radio), then those radios’ transmissions cannot be interrupted and the radio user
instead transmits the Emergency Alarm in accordance with the configuration of the polite and
impolite Emergency Alarm fields in the CPS, if Emergency Alarm is attempted while receiving
another radio’s uninterruptible transmission.
If the interruption of the voice transmission is successful, the radio uses the established
procedures for either Emergency Alarm or Emergency Alarm with Call, depending upon the CPS
configuration, once the channel has been cleared. The radio user whose transmission was
interrupted receives a Talk Prohibit Tone until the PTT is released.
If the interruption of the voice transmission fails, the radio then uses the established procedures for
either Emergency Alarm or Emergency Alarm with Call, depending upon the CPS configuration.
However, the probability of success diminishes because the original voice transmission had not
been successfully cleared from the channel.
If the voice call on the channel is not transmitting an interruptible voice signal, the radio uses the
established procedures for either Emergency Alarm or Emergency Alarm with Call, depending
upon the CPS configuration, again with a lower probability of success.
To Next Page
Loading...
