The aim of this article is to give an overview on the basic implementation of Emergency mode for PoC devices.
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 server and user settings to configure the action taken when receiving emergency calls - e.g. talkgroup scan for emergency channels.
Emergency calls are received server wide by default. i.e. radios will receive emergency calls regardless of which channel (Talkgroup) the are currently using - or alternatively,
each user account allows restricting incoming emergency calls to be limited to those initiated from another user in the same channel (enable ‘ignore emergency calls from other channels’). note: This is an ‘either/or’ setting and when enabled for a user, emergency calls initiated from other channels will not be received)
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 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)
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