Abstract: According to the location-specific vehicular subscriber node and sink node， the end-to-end throughput of the vehicular networks was improved by selecting out the optimal trunk node. Incorporating this issue into the vehicular networks model which is based on the group-based acknowledgement mechanism， and combining with data retransmission technology and multi-hop relay technology， the optimal trunk node selection (OTNS) algorithm was presented. With the help of the nonlinear optimization method， the location of the optimal trunk node between the vehicular subscriber node and sink node was ultimately determined， which made the end-to-end throughput between the vehicular subscriber node and sink node reach its maximum. Finally， the effectiveness of this algorithm was verified through the simulation experiments， which showed that the selection of optimal trunk node is useful for increasing the vehicular networks performance. Compared to not using the optimal node， the vehicular networks end-to-end throughput expectation was improved on the basis of the proposed method.

Key words: multi-hop relay technique, group-based acknowledgement mechanism, throughput, vehicular network, package receipt rate