title: A Cooperative Downloading Method for VANET Using Distributed Fountain Code.
abstract: Cooperative downloading is one of the effective methods to improve the amount of downloaded data in vehicular ad hoc networking (VANET). However, the poor channel quality and short encounter time bring about a high packet loss rate, which decreases transmission efficiency and fails to satisfy the requirement of high quality of service (QoS) for some applications. Digital fountain code (DFC) can be utilized in the field of wireless communication to increase transmission efficiency. For cooperative forwarding, however, processing delay from frequent coding and decoding as well as single feedback mechanism using DFC cannot adapt to the environment of VANET. In this paper, a cooperative downloading method for VANET using concatenated DFC is proposed to solve the problems above. The source vehicle and cooperative vehicles encodes the raw data using hierarchical fountain code before they send to the client directly or indirectly. Although some packets may be lost, the client can recover the raw data, so long as it receives enough encoded packets. The method avoids data retransmission due to packet loss. Furthermore, the concatenated feedback mechanism in the method reduces the transmission delay effectively. Simulation results indicate the benefits of the proposed scheme in terms of increasing amount of downloaded data and data receiving rate.
authors.affiliation: College of Computer and Communication Engineering, China University of Petroleum, Qingdao 266555, China. liujianhang@upc.edu.cn.
authors.forename: Jianhang
authors.initials: J
authors.lastname: Liu
authors.affiliation: College of Computer and Communication Engineering, China University of Petroleum, Qingdao 266555, China. audiproduct@gmail.com.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Institute of Computing Technology Chinese Academy of Sciences, Beijing 010190, China. wangqi08@ict.ac.cn.
authors.forename: Qi
authors.initials: Q
authors.lastname: Wang
authors.affiliation: College of Computer and Communication Engineering, China University of Petroleum, Qingdao 266555, China. lishibao@upc.edu.cn.
authors.forename: Shibao
authors.initials: S
authors.lastname: Li
authors.affiliation: College of Computer and Communication Engineering, China University of Petroleum, Qingdao 266555, China. chenhaihua@upc.edu.cn.
authors.forename: Haihua
authors.initials: H
authors.lastname: Chen
authors.affiliation: College of Computer and Communication Engineering, China University of Petroleum, Qingdao 266555, China. cuixuerong@upc.edu.cn.
authors.forename: Xuerong
authors.initials: X
authors.lastname: Cui
authors.affiliation: Institute of Computing Technology Chinese Academy of Sciences, Beijing 010190, China. sunyi@ict.ac.cn.
authors.forename: Yi
authors.initials: Y
authors.lastname: Sun
keywords: VANET; cooperative downloading; digital fountain code