Cooperative content downloading in vehicular ad hoc networks

Abstract

Abstract Content downloading in vehicular ad hoc networks supports the large file sharing, the entertainment experience and the mobile office. However, because of the high velocity, the frequent topology change, the limited bandwidth and a small number of roadside units, it is difficult to directly transmit the contents to their requesters through only one hop. This paper proposes a cooperative content downloading scheme in vehicular ad hoc networks, named CCD. It introduces the direction, range and timing constraints to select appropriate cooperative nodes, which improve the contact probability between the cooperative nodes and the request senders. Additionally, CCD computes the number of copies for each block according to its importance and urgency, and then schedules the block transmission accordingly. Experiments show that compared with existing schemes, CCD has a short delay and a small transmission overhead.