Patent ID: 9554322
Date: 2017-01-24
CPC Classifications: H04W

Claim:
1. A transmission control method for a vehicular ad hoc network system, the vehicular ad hoc network system having a plurality of mobile nodes with communication capability, wherein the mobile nodes comprise a source node, a destination node, and a plurality of relay nodes, the transmission control method comprising: each of the mobile nodes periodically broadcasting a beacon message which includes a mobility information; each of the mobile nodes receiving the beacon message that is broadcasted from each of the neighboring mobile nodes, and correspondingly updating a connection state table associated with each of the mobile nodes according to the beacon message, wherein the connection state table records a coverage remaining duration between each mobile node and each of the neighboring mobile nodes; establishing a network connection between the source node and the destination node such that the source node transmits a data packet to the destination node through the relay nodes; each of the relay nodes determining whether the coverage remaining duration between the relay node and the subsequent mobile node is less than a predefined threshold according to the connection state table upon receiving the data packet; and when determined that the coverage remaining duration is less than the predefined threshold, the relay node transforms into a proxy node, stores the data packet, and establishes a first sub-connection with a subsequent proxy node or the destination node; wherein the step of calculating the coverage remaining duration comprises: when the relay node determines that the speed thereof is less than the speed of the subsequent mobile node according to the connection state table, the relay node calculates the coverage remaining duration using equation (1): wherein, CRD represents the coverage remaining duration; R represents the transmission distance of the relay node; when the relay node determines that the speed thereof is greater than the speed of the subsequent mobile node according to the connection state table, the relay node calculates the coverage remaining duration using equation (2): wherein CRD represents the coverage remaining duration; R represent the transmission distance of the relay node;