SmartBeaconing

SmartBeaconing is an algorithm created by Steve Bragg for adjusting the transmit rate by the speed and heading changes on the tracker. As the tracker moves faster, the transmit rate will increase linearly. SmartBeaconing also uses CornerPegging to cause transmissions to occur when the tracker turns corners. In order to use SmartBeaconing, the GPS must send speed and heading information with the GPRMC sentence.

The SmartBeaconing algorithm works like this:

IF (speed < slow_speed) // "Stop" threshold

beacon_rate = slow_rate;

ELSE { // We're moving; adjust beacon rate to speed, and peg corners

turn_threshold = min_turn_angle + turn_slope / speed; // adjust turn threshold according to speed

IF (heading_change_since_beacon > turn_threshold) AND (secs_since_beacon > min_turn_time)

CornerPeg = TRUE; // Corner pegging

IF (speed > fast_speed) // Adjust beacon rate according to speed

beacon_rate = fast_rate;

ELSE

beacon_rate = fast_rate * fast_speed / speed;

}

if ((secs_since_beacon > beacon_rate) OR CornerPeg)

// ... send beacon