The aim of this article is to give an overview on the basic implementation of Emergency mode for PoC devices.
A dynamic group is a temporary group. When a device initiates an emergency call (DN radio or Smartphone), a new ‘dynamic’ group is created.
(a dynamic group is a temporary group)
DN radios participating in the emergency call move to the emergency dynamic group.
note: Dispatchers have an options for what action to take when receiving emergency calls in relation to moving Talkgroups manually or automatically.
By default, (options available)
1. Emergency calls are semi-full duplex. The initiating radio transmits ‘open’ mic continuously (no TX/RX cycles) on a new ‘dynamic’ Emergency group. (not related to the current selected group). The receiving radio or dispatcher must press their PTT to talk back to the initiating radio (or smartphone), and while PTT is pressed, the call is then in ‘full duplex’ mode. (i.e. transmitting and receiving simultaneously).
2. All devices are always listening for this ‘Emergency’ group . (unless receive emergency calls is set to when ‘receive emergency calls’ is enabled.
note: 'receive emergency calls' is enabled/disabled per user via T.Commander. DN radios additionally have a menu option for disabling emergency RX/TX which allows user control. (but cannot override server user settings if emergency is disabled)
DN Radios:
Making an emergency call:
To initiate an emergency call, press and hold the top ‘orange’ button for >2s. Emergency calls can also be initiated automatically in Lone Worker or Man Down modes of operation.
Receiving an emergency call:
When DN radios receive an emergency call, there is an audio alert, and the LED flashes Red. In addition, the radio will hear the ‘live’ microphone voice audio from the initiating radio.
There is an option now to accept or reject the emergency call, by using the ‘right’ or ‘left’ keys below the display.
Accept: (RH key) the audio alert is cancelled, and the radio joins the emergency group. Press PTT to talk back to the radio sending the emergency call.
Reject: (LH key) the radio exits emergency receive mode and resumes normal operation on the selected channel.
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