The vehicular ad hoc network (VANET) has attracted a lot of interest recently. However, traditional VANET is just an instantiation of MANET in which nodes are treated equally for data delivery. We first analyze the unique features of urban VANET that vehicles have different types, and move as clusters due to the influence of traffic lights. Then a two tier architecture called Mobile Infrastructure Based VANET (MI-VANET) is proposed. In this architecture, the buses constitute a mobile backbone for data delivery while the low tier is composed of ordinary cars and passengers. MI-VANET will not only bring the benefit that ordinary cars do not have to forward packets for other nodes, but also improve the network connectivity. The corresponding Mobile Infrastructure Registering (MIRG) and Mobile Infrastructure Routing (MIRT) algorithms are also presented. The bus line information is made full use in MIRT. Simulation results show that there is a 40-55% improvement in delivery ratio while the throughput is even doubled compared to GPSR in traditional VANET.

No abstract

A soluble Pt nanocluster catalyst (Pt-GLY) is efficient in the absence of base for aqueous-phase aerobic oxidation of, in particular, non-activated alcohols with high recyclability.

No abstract