en:c-its:messages:denm
DENM (Decentralized Environmental Notification Message)
DENMs are event-driven warning messages (ETSI EN 302 637-3). While CAMs are broadcast continuously, a DENM is only transmitted when something exceptional happens, and it is repeated for as long as the event is valid.
Typical triggers:
- roadworks (including mobile roadworks / safety trailers)
- stationary or broken-down vehicle
- traffic jam ahead
- emergency vehicle approaching
- adverse weather or slippery road
A DENM contains, among other things:
- the event type (a standardized “cause code”)
- the position and the area affected by the event
- detection and validity times
On motorways, DENMs are typically sent by RSUs and roadworks safety trailers; vehicles generate them e.g. for emergency braking or breakdown warnings.
en/c-its/messages/denm.txt · Last modified: by fasteiner