Apparatus and method of adaptive transmission power control for vehicle communication. A vehicle (Fig 1C, 100) has a driving assistance unit (Fig 1C, 106) which determines 408 an expected speed of target vehicles (Fig 1C, 118, 120) in the vicinity of the transmitting vehicle and a communications module (Fig 1C, 102) which determines 404 a type of message 402 received from a subsystem of the vehicle and broadcasts the message at a power level 410 based on the message type (Fig. 2A, 202) and the expected speed of the target vehicles. The message type may be public safety 408 or private service 412, where its private service the power level may be based on a range request accompanying the message and where its public safety the power level may be based on the expected speed or may be based on the range request which may be increased if the difference between the expected speed of the target vehicles and an actual speed of the vehicle satisfies a threshold (Fig. 2C, 212)
Adaptive transmit power control for vehicle communication