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.

Collaborative Content Downloading in VANETs with Fuzzy Comprehensive Evaluation

“…Digital fountain code (DFC) is proposed and applied in the field of cooperative downloading for VANET. As long as enough data packets encoded by hierarchical fountain code are available, the client can recover the raw data and avoid data transmission interruption [16,17]. In Reference [18], a fuzzy logic-based resource management (FLRM) scheme was proposed, and the lifetime of each storage resource was defined by the proposed fuzzy logic-based popularity evaluation algorithm.…”

Fuzzy logic-based integrity-oriented file transfer for highway vehicular communications

“…where (μ) denotes the gamma function, which is defined as 7,588]. is the average received power before envelope detection, which is defined as…”

“…C. Lai et al [6] propose a secure incentive scheme to achieve fair and reliable cooperative (SIRC) downloading in highway VANETs. J. Liu et al [7] propose a cooperative downloading method for VANET using digital fountain code (DFC) to increase the amount of downloaded data and enable the transmission to be more robust in a vehicular environment. Ota et al [8] propose a cooperative downloading algorithm called maxthroughput and min-delay cooperative downloading, in which the roadside units (RSUs) intelligently select vehicles to serve towards the minimal average delivery delay of file transfer.…”