Timely and cost-efficient multi-hop data delivery among vehicles is essential for vehicular ad-hoc networks （VANETs）, and various routing protocols are envisioned for infrastructure-less vehicle-to-vehicle （V2V） communications. Generally, when a packet （or a duplicate） is delivered out of the routing path, it will be dropped. However, we observe that these packets （or duplicates） may also be delivered much faster than the packets delivered along the original routing path. In this paper, we propose a novel tree based routing scheme （TBRS） for ultilizing the dropped packets in VANETs. In TBRS, the packet is delivered along a routing tree with the destination as its root. And when the packet is delivered out its routing tree, it won＇t be dropt immediately and will be delivered for a while if it can arrive at another branch of the tree. We conduct the extensive simulations to evaluate the performance of TBRS based on the road map of a real city collected from Google Earth. The simulation results show that TBRS can outperform the existing protocols, especially when the network resources are limited.
SONG ChaoLIU MingGONG Hai-gangCHEN Gui-haiCAO Jian-nong
An artificial fish-swarm based coverage-enhancing algorithm(AFCEA) for visible light sensor networks is proposed.In AFCEA,the improved optimization algorithm is used into the solution for coverage-enhancing in directional visible light sensor networks with the rotational direction model.Compared with other classic directional sensor networks coverageenhancing algorithms,AFCEA can achieve a higher directional sensor networks coverage with less iterative computing times.
