Fig. 3From: Collecting road traffic information using vehicular ad hoc networksDifferent scenarios for nodes to return acknowledgement for the NP message. a Only N 1 and N 2 return acknowledgement to the NP message from S. b N 1−N 3 are selected as the next forwarding nodes in other segments when the query reaches the intersection. Nodes in segments B, D, F, and G do not respond to the NP message from S Back to article page