CTE messages have high overhead when compared to
beacon messages. To avoid overloading the communication
channel, such messages are only sent, at a frequency of only
0.1 Hz (one message every 10 seconds), when the local
LOC for a vehicle is higher than Cth. Furthermore, only
vehicles with LOC levels higher than Cth participate in the
retransmission process, and if there already is a passing vehicle
ahead, the vehicle behind it cancels its own transmission. The
process ends when the network relay messages arrive in a
region where the local LOC detected by the vehicles is less
than Cth.