IPSC3 can relay government public warnings as spoken announcements to nearby repeaters, POC handsets and located personal hotspots, in that order. The independent public-alert worker supports modular feed adapters, geographic selection, persistent delivery history, hourly repeats and confirmed cancellation announcements. Automatic transmission is disabled on new installations.
This is a supplementary amateur-radio service, not an official emergency warning system. Do not rely on IPSC3 for personal safety. Refer to the issuing agency, emergency broadcasters and emergency services for current advice. An unavailable feed, an expired warning or a locally muted relay is not an all-clear announcement.
| Module | Source | Default Voice Eligibility |
|---|---|---|
| NSW Rural Fire Service | Official RFS CAP incidents feed | Watch and Act and Emergency Warning. Routine Advice can be enabled separately. |
| Bureau of Meteorology | BOM CAP warnings distributed by WMO SWIC, with BOM geographic boundaries | Severe/Extreme CAP warnings and explicitly named severe weather, tsunami, tropical cyclone and major-flood warnings. Routine warnings can be enabled separately. |
Source links, held warnings, source errors and announcement outcomes are visible to administrators under Configuration > Public Alerts. The original agency link remains available for the complete warning. BOM source health is based on successful polling, not on requiring a newly issued warning every 30 minutes: RSS publication time records a content update, not a heartbeat. Each CAP warning must still be effective and unexpired, present in recently polled data and geographically valid. Failed or overdue polls hold announcements. RFS's separate publisher-heartbeat check remains in place.
The default destination is All Call 16777215 on the configured call-channel timeslot. An administrator can instead select the actual configured call-channel talkgroup. All Call does not automatically cross timeslots or frequencies. Reception was verified on a Motorola radio and a Chinese radio through the VK2FLY Motorola repeater on TS2; other repeater types and radio combinations still require operational testing.
The spoken identity is the individual repeater callsign. The DMR source ID is that repeater's configured Radio ID. Example:
This is [local repeater callsign] with a public alert from the NSW Rural Fire Service. The following warning was issued ...
Playback goes directly to the selected endpoint, never through network-wide talkgroup, scan, trunk or master fanout. The sender conservatively defers while there is recent voice activity on the timeslot. It does not change dynamic camps. Different warnings are spaced at least five minutes apart on a repeater by default; confirmed cancellations may bypass that spacing.
POC receives native PCMU audio, not audio that has been encoded to AMBE and decoded again. The spoken and displayed identity is IPSC3. The wire source Radio ID is the existing system service ID 9998; the displayed callsign and origin are IPSC3, with origin type public_alert.
Announcements use the existing call_start/call_end messages and call_status=2 (Emergency). The client's Emergency receive option must be enabled. A geographically selected handset can hear the warning regardless of its selected group; a handset currently transmitting is not interrupted. Normal selected/scan audio resumes afterwards. Other devices with the same Radio ID are not implicitly selected. No client protocol upgrade is required for devices that already support Emergency reception.
Personal hotspots use their reported coordinates, falling back to the centre of an available Maidenhead grid locator, as on the map. Unknown or invalid positions without a valid locator do not qualify. A provisioned MMDVM repeater remains in the repeater class and is not selected twice.
For each warning, repeater playback attempts are queued first. After pending repeater playback drains, POC delivery is attempted, followed by hotspot delivery. Busy or failed endpoints are retried later rather than permanently blocking the other recipients. A bounded serial RF queue limits both job count and waiting audio, so a large hotspot population cannot overflow the player.
Hotspots hear the selected standard voice identifying the local hotspot's configured callsign: This is [local hotspot callsign] with a public alert.... Only POC announcements say This is IPSC3. The hotspot's on-air source Radio ID remains 9998; the spoken callsign is separate from that wire identity. The full hotspot ID, including its suffix, identifies the target only; it is not copied into the 24-bit on-air source field. Simplex hotspots use TS2; duplex hotspots use the configured call-channel timeslot. The configured All Call/call-channel destination applies to both repeaters and hotspots.
Playback is local to each selected hotspot, with its identity and position checked again before sending. Scan and dynamic camps are not changed, and alerts never fan out to trunks or the master. The same hourly repeat, update, mute and cancellation safeguards apply. A confirmed cancellation can still reach a previously notified connected hotspot after it moves outside the original area. Supervised tests must explicitly include hotspots; ordinary existing tests do not start sending to them.
The dashboard's selected standard voice supplies the ElevenLabs voice settings. The existing prompt builder's filtering, level conditioning, limiting and DMR AMBE bit conversion are reused. Audio is cached by voice and spoken text. An isolated, low-priority software vocoder prepares AMBE for repeaters without occupying live hardware channels. Long warnings are held rather than silently truncating safety instructions.
Government polling, parsing, geography, text-to-speech requests, persistent history and scheduling run in a separate process. Repeater jobs are dispatched to a dedicated bounded playback thread so a long announcement does not hold up ARS/SMS or normal prompt processing on unrelated endpoints. Requests for the same endpoint and timeslot wait for its announcement reservation. The POC player has a private local Unix socket and a separate pacing thread; geometry work is outside the shared voice-state lock. There are no added HTTP requests or database queries in received voice-packet handlers.
Each adapter supplies a stable incident key, agency, source identifier/references, UTC issue/effective/expiry times, official severity, headline, description, instructions, source URL and WGS84 geometry. It must distinguish actual public warnings from test/private messages and explicit cancellations from missing data. The common scheduler handles selection, synthesis, persistence and delivery, so a new agency adapter does not need to alter the RF or POC packet handlers.
RFS information: © State of New South Wales (NSW Rural Fire Service). For current information go to www.rfs.nsw.gov.au. BOM warning and boundary information: Australian Government Bureau of Meteorology; refer to official BOM warnings. Feed availability and redistribution remain subject to the issuing agencies' terms.